Masonry Construction Manual - Building Science

Building science

Buildingscience Joachim Achtziger

2.6.1 Surfaceresistancesin m2K V Directionof heat flow Horizontal R" 0.10 0.13 R

0,04

. location,orientation and formof the structure, . physicalpropertiesof materialsand componentsusedfor the structure, Thethermalinsulation of a buildingis intended ' the designof systemsfor the technicalserto contributetowardsa hygienicand comfortvices, climate,whichis notdetrimental ableinternal . performance featuresfor the componentsof to the heaithof the occupantsand usersof the thesesystems,and building,and at the sametimeprotectsthe . the behaviour of the usersof the building. effectsof structureagainstthe climate-related Theenergy moisture andtheirconsequences. of planningand designstanrequiredfor heatingin thewinterand measures Thecombination climatein the dards,standardswith generallyacknowledged to providean acceptableinternal of for designdata,standardsfor the measurement summerwithoutthe useof air conditioning with componentsand materialsas wellas those coolingmustbe optimizedin conjunction coveringproductsis shownin a verymuch the necessarythermalinsuiationand energyforminfig.2.6.2. and generalized Thesedays,thermalinsula- simplified savingmeasures. tionto a buildingis notjusta meansof saving Thequalityof a buildingin energytermsis accordingto a designstandard. elementin an environ- calculated energybut an important Furtherrulesare necessaryfor assessingthe Therefore, mentalprotectionprogramme. of partsof a building, frombuilding thermalperformance reducingemissions of pollutants such as roomsadjacentthe soil,roomsin the heatingsystemsis an importantaspect. roofspaceor partsof the buildingwith lower' Besidessavingheatingcostsfor the user,an as well as standardsfor specifytemperatures, increasingly importantfactor,evermorepreof components ing the thermalperformance ciousenergyand fuel resourcesare also behaviouruponheating and theirnon-constant spared. and cooling.Tablesof valuesor measurements ProductsDirective[13],the The Construction of componentspreparedaccordingto estabmostimportantelementin the creationof a lishedrulesservefor the calculationof transEuropeanSingleMarketfor the construction missionheatlossesfroma buildingenvelope the importanceof industry,acknowledges and givenheatgains.Fufther,componentscan thermalinsulation and definesthe areaof be assessedaccordingto theirconstituents, "Energyeconomyand heatretention"as one basedon the propertiesof the materials the whole, requirements. On of six essential employed.Therefore,a complete,coordinated the costsand adaptationproblemsof Europeanstandardization standardizedconceptfromthe productproperare outweighedby the for is available tiesto finalenergyrequirement benefits,The effectsof theseare to: . harmonize of a building.In the performance describing the markets, . createuniformframeworkconditionswithin Germany,DIN4108remainsas the National andthe publication Document Application t h eE U , ' attainEuropean Thefirst describingnationalrequirements. supplyconditions, ' set uniformevaluationand testingstandards, nationalmeasuresfor savingenergyin the . set uniformstandardsof qualityrecognized within wereestablished heatingof buildings Act of 1976, throughoutEurope;differentstandardsin dif- the scopeofthe Energy-savings Act whichledto the 1977ThermalInsulation ferentcountriescan be assessedaccording '1982 1995. in and revisions classes. and itssubsequent to a systemof gradedperformance Act of 2001hasthe The new Energy-savings The objectiveof the principaldocument"Ener- potentialto achievea further30%savingin A complete energyin the heatingof buildings. gy economyand heatretention"is, takinginto forthe energyplanningconceptis available accountthe location,to keepdownthe contakingintoaccountheatdesignof buildings, sumptionof energyrelatedto the useof a of the energy ing systemsand an assessment and to buildingand itstechnicalsystems, guaranteean adequateof standardof thermal carrier. comfortfor the occupants,Thisencompasses the followingmainfactors: and standardizes Thermalinsulation

Downwards 0.17

160

d

Thermalinsulation

Heat transfer, thermal insulation parameters, terms

Heattransfercan take olace in the formof conductionin solid,liquidand gaseousmedia, and in the formof radiationin transparent materials and vacuum.In buildingmaterials, heattransferis expressedby the propertyof thermalconductivity.Thermalconductivityl. specifiesthe heatflow in W passingthrough 1 m2of a 1 m thick layerin t h whenthe temperaturegradientin the directionof the heat flowis 1 K. The lowerthe thermalconductivity, for a given the betteris the thermalinsulation Thethermalinsulation thickness of material. by capacityof a componentis characterized Ihe thermalresistanceR, lt is determinedby dividing thethickness of the layerconcerned (inm) by the material'sthermalconductivityl. (inWmK). Multi-layer componentsrequirethe valueof each layerto be calculatedseparately accordingto this method.Thetotalof the indiR vidualvaluesgivesthethermalresistance forthe completecomponent.The higherthe the betteris the thermal thermalresistance, insulation. To determinethe thermaltransmittance througha component,we also needto know the internaland externalsurtaceresisfanceR", and R"".Thesurfaceresistanceis the resistanceof the boundarylayerof air to the transfer of heatfromthe internalair to the compoThe surnentand fromthisto the external.air. faceresistances are generallystandardized of the component accordingto the orientation (vertical, horizontal) and the externalair circuventilated,notventilated) lation(unrestricted, as givenin table2,6.1.Theyhavebeendeterminedfor a degreeof emissionsfromthe surfaceof e = 0.9 and a wind soeedn = 4 m/s at theexternalsurface.Thetotalof all resistances - thoseof the layersof the componentand the surfaceresistances of the boundarylayersof air - is the total thermalresistanceR- which the completecomponentappliesto resistthe flow of heat.The reciprocalof this valueis the thervarimaltransmittance U - the characteristic of a building ableforthethermalinsulation for The U-valueis fundamental component. of a buildcalculating the heatingrequirement the betteris the ing.Thesmallerthe U-value, The calculationof the therthermalinsulation. malresistance comof single-and multi-layer oonentsas well as the U-valueis shown of the Uin 2.6.3,Thecalculation schematically valuefor comoonentsmadeJromseveral neighbouring sectionswith differentthermal conductivities is dealtwith in the sectionentitled"Thermalbridges".The mathematical of heattransferand temperature assessment gradientsin componentsis a relativelydifficult problemdependingon timeand geometry. Therefore, to simplifythe workwe assumestationary,i.e.constant,temperatures on both sidesof the componentas well as a onedimensional heatflowacrossthe thicknessof

2.6.2 Diagramof relationshipbetweenmaterials,componentsand designstandardsfor assessingbuildingsin terms of energy performance

Tabularvalues lvlethodsof calculation Methodsof measurement

Fabricated on slte

\

-,,\ \-/ ,/\

2.6.3 Calculationof thermalresistanceand thermaltransmittancevaluesfor single-and multi-layermasonry components Sketchof principle

Construction

Equation

Thermalresistance Single-layercomponent

_o ,'R

1

1

1

2 ,/,4

Thermalresistance lvlulti-layer componenl

2 ]0,

d2

n=-

dr

ln',

+ -

d2

rnz

+

1 '!Rn

o"l

$i

Thermaltransmittance Single-or multi-layer component

r61

Building science

2.6.4 Thermalconductivityof dry expandedclay and expandedshaleconcretesampleswith and withoutvarious quartzsand additionsby volumeof total aggregatecontent(%) in relationto gross density(averagetemperature 10"C),afterW. SchLlle,Gieseckeand Reichardt[195] Expandedclay concrete

Expandedshaleconcrete

0,90

0.90

0,80

0,80

u

!

30o/o

0.70

;

30o/o1

o.70 209

2Oot

0.60

a l c o a 6

0.40

E

i.-

0.60

0,50

o c F

-/u

0.50

-,-''

Vo

'{.

1 "6n

0.40

0.30

0.30

1000 1 1 0 0 1 2 0 0 1 3 0 0 1 4 0 0 1 5 0 0 1 6 0 0 1 7 0 0

1200 1300 1400 1500

Bulk density(kg/m3)

2.6.5 Orderof magnitudeof thermalconductivity (WmK) of solid constituentsof buildingand thermal insulationmaterials,afterJ.S. Cammerer[29] Inorganicbuildinglra!glq!s Crystalline perpendicularto crystalaxis 4 . 7I o 7 . O parallelto crystalaxis to 14 Quaftzite 6 Limestone,marble,granite 1 . 6t o 4 , 0 Basalt,feldspar,sandstone Amorphoussolidifiedmells such as blastfurnaces]-agand glasses 0.7 Io 1.2 N a t u r aol r q a n i C s u b s t a n c e s 0.3to0.4 0 . 1 6t o 0 , 3 5

2.6.7 Thermalconductivityof buildingmaterials 1,0

sufThisapproachis generally the component. with ficientlyadequateforwinterconditions permanently heatedinteriorsand constantlow temperatures outside,as wellas for calculating a meanheatlossovera longerperiodof time. the heatflow At equilibrium,

2.6,6 Variables.svmbolsand unitsused in thermal performance__ _ Phvsicalvariable Svmbol Unit Temperature o "c Thermalconductivity 7, W/mK Thermalresistance R m'?K,AiV Internalsurfaceresistance 'R- s m2K.AiV R Externalsurfaceresistance m,KAV Totalthermalresistance R (airto-airresistance) m2K,\N Thermaltransmittance WlmzK Heatflow ; q Heat flow rate W/m2 Specificheat capacity c J,4
< D = U x A ( O- iO " ) passesthroughan externalcomponentwithan air areaA on onesideof whichthereis internal at a temperatureOiand on the other,thereis the externalair at a temperature8e.Therefore, U is criticalfor the transthermaltransmittance missionheatlossthroughthe component. of the UHowever,the graphicrepresentation valuein fig.2.6.8revealsthatonlyslight improvements are possiblebeyonda certain beThisnon-linear thickness of component. of increasing haviourleadsto the situation cosisfor moreand moreinsulationhavingever Thevariables, effects. smallerenergy-saving the for assessing symbolsand unitsnecessary thermalperformance of the buildingenvelope detailsareconaregivenin table2.6.6.Further tainedin DINEN ISO7345andthe respective Dartsof DIN4108. Thermal conductivity of building materials

Withthe exceptionof verydensestone,building materialsare porousto someextent.They voidsof varioussizesin varicontainair-filled and thesecan havea sigous arrangements, nificanteffecton the transferof heat.Thethermalconductivity of masonrydependson: . thethermalconductivity of the solidconstituents, . the porosityor gross/bulkdensity, . the nature,sizeand arrangement of the pores, ' the radiationpropertiesof the boundarywalls of the voids, 'temperature, and . the wateror moisturecontent.

05 0.4 0.3

0.2

0.1 <> c

ss O l c C

o a

5 E

o.o3

o g F

162

of the material As the thermalconductivity dependson thetemperature underobservation for buildingpurwithinits rangeof application, posesall thermalconductivityvaluesare relatof 10"Cso that ed to a meantemperature can be made.For uneouivocal comparisons the samereason,materialparametersare specifiedfor the dry stateof the material,initially withouttakingintoaccountthe fact that moistureincreasesthe thermalconductivity. of theorder Table2.6,5providesan overview of of magnitudeof the thermalconductivities building usedto manufacture solidmaterials and thermalinsulationmaterials.Materialswith mainlycrystalline components exhibita higher thanthosewithvitreousor thermalconductivity Forinstance, the lime-based components. additionof quartzsandto concreteor mortar effecton the therhas a noticeablydetrimental mal conductivity. Measurements of concrete

Thermalinsulation

buildingmaterials beingmarketedinternationwithdifferentquartzcontentsare shownin fig. ally.Thenominalvaluefor thermalconductivity 2.6.4.Generally speaking, the useof aggregatesconiainingquartzcan be assumedto is the valueto be expectedfor the thermal propertyof a buildingmaterial or insulation reducethe insulatingeffectof the concreteby variableinflu- product,assessedby way of measurements 20%.However,the characteristic encingthethermalconductivity of buildingand takenat a referencetemperatureand humidity accordingto table2.6.11,specifiedfor defined insulation materialsis the grossdensity.This percentiles rangesand correand confidence relationship is shownin Iig.2.6,7- the evalin a spondingto an expectedservicelifeunder uationof morethan 1000measurements normalconditions.Theterm "servicelife"also Europeanresearchproject.Afterbeingincorporatedintoa structure,especiallyin external includesthe ageingbehaviour of products, materials withhighsuchas thermalinsulation exhibita components, buildingmaterials prooellants, greateror lesserwatercontent.Owingto the whichovertimeundermolecular go an exchangeof gaswiththe surrounding generally thisis relatively smallproportion, air,or the settlementbehaviourof loosetherknownas moisturecontent.Dependingon the porousstructureand the magnitudeof the in voids,Onlythe mal insulation materials moisturecontent,the watermay parilyor com- materialscatterand the influenceof moisture pletelyfilllargerand smallerporesor just are relevantfor masonryproducts. fhe design valuefor thermalconductivityis adhereto the sidesof the ooresor in corners exhibita the valueof a thermalpropertyof a bullding of thepores.Dampbuildingmaterials and material or oroductundercertainexternal higherthermalconductivity comparedto the whichcan be regardedas internal conditions, drystate,and this dependson the moisture typicalbehaviourof the materialor productin content,which in turn is relatedto the type of of a component.The its formas a constituent material. by the user/ designvaluesaredetermined Figure2.6.9showsthe thermalconductivityof planner,buildingauthorities stanor national variousbuildingmaterials as a functionof the to the intendedapplicadardscorresponding moisturecontent;this can be expressedrelator climed to eitherthe volumeor the mass.lf thether- tionof the product,the environmental as wellas the purposeof the aticconditions malconductivity in the dry stateand the moisc a l c u l a t i oen.,g . : turecontentof the buildingmaterialis known, thethermalconductivityin the moiststatecan be calculated accordingto DINEN ISO10456 . energyconsumptron . designof heatingand coolingplants usingthe equation ' surfacetemperature . compliance withnationalbuildingcodes x F, lu,*= 1,.,0,u . investigations thermal of non-constant u1) c o n d i t i o ni sn b u i l d i n g s 'trm -_" afu(u2, 't rm -_' 6 f , { V 2 - v j )

where: fuandf, = conversion factorfor mass-and volume-related moisturecontentrespectively u, andf, = moisturecontent0 of dry material moisu, and ry, = mass-and volume-related turecontentrespectively.

designvaluescan be Thermalinsulation derivedfromthe nominalvaluesby meansof factorsgivenin DINEN ISO the conversion for thermalinsulation 10456.Thisis customary Designvaluesfor masonrymaterials materials. are derivedfromthe thermalconductivityin the dry state.

2,6.8 ThermaltransmittanceU in relationtothermal resistanceR

U (WmzK) 6 5 4

3 2.38 2

1.49 1.O7

oasffi 4.0

3.0

2.0

R (m2Kl,{)

2.6.9 Thermalconductivityof buildingmaterialsin relationto moisturecontent(volume-and massrelated) Y6lurns-lsl3tsl ----mass-related

Thermalconductivity(W/mK)

,-/ 0,5

-'

clay brrcKs

3 P = t c r!6 kg/m

.-t-'

o/o 1'= 43

0,4

Thermal insulation provided by layers of air

Layersof air in componentstransferheatby Themoisturecontentsu and y commonin practice,as well as conversionfactorsfor the and radiation. conduction, convection The variousheattransportmechanismshave moisture content,are givenin DINEN'12524 for air the effectthat,unlikewith solidmaterials, to table2.6.10.Thestandardcorresponding the thermalresistanceR doesnot risewith and y izedmoisturecontentsu (mass-related) (volume-related) thicknessbut insteadreachesa increasing are relatedto the moisture mate- maximumvalueandthenremainsconstant. contentequilibriumof the corresponding of layersof air according Thermalresistances rialat 23'C and 5Oo/o relativehumidity,or 23'C t o t a b l e2 . 6 J 2 a r es p e c i f i eidn D I NE N I S O and 80%relativehumidity.The moisturecon6946and may be takenlntoaccountonlywhen tentsin the desiredreference ambientcondianalysingthermalperformanceif they are isotionsand the conversionfactorsfor the influlatedfromthe outsideair.Suchlayersof air enceof the moisturecontenton the thermal masonry individual- alsoincludethe cavitiesin twin-leaf conductivity can alsobe determined '1053becausethe openingsin the wallsto DIN ly for certainmaterialsby way of experiment, withthe aim of achievingmorefavourablether- outerleafare too smallto bringaboutan The exchangeof air withthe outsideair.The extent malconductivity valuesfor realsituations. to achieve to whicha layerof airwithsmallopeningsto term"nominalvalue"was introduced for the propertiesof theoutsideair can stillbe regardedas a a uniformspecification

'--

--'---z

P u nlce concrele 1 0 1 5k g l m ' 58 lo

Gas concret(??/evtl.aerated c )2 P = 540 kg/nr 3 N=79o/o

----:== 0,1

Perlite N=87

o/o

---/ .a-:----= 303 ko/m 3

=-==:=46 lvloisturecontent (%)

163

Building science

2.6.10 Moisture-related propediesof masonrymaterials l\.4aterial

Moisturecontental 23"C,50%re

values layer,or to whichinsulating stationary poorlyor well ventilatedlayersof air can be g i v e na r es h o w ns c h e m a t i c a il nl yf i 9 . 2 . 6 . 1 3 . to Smallor dividedair spacescorresponding masonry tig.2.6.14,as occurin perforated perforatedclay bricksand units,horizontally gripaids,requirespecialconsideration. In thesecases,the geometryof the perforations ratio- has an influthe gap width{o-thickness thermalconductivity of enceon the equivalent the void,Thethermalresistances of air spaces withany dimensions can be calculated accordingto DINEN ISO6946,Thethermalresistanceof an air cellis foundusinqtheeouation:

Moisture content at 2 3 ' C , \ O a / ran

Solid bricks C a l c i u ms i l i c a t e Pumiceconcrete Normal-weiqht concrete concrete Concretewith predominantlyexpanded with blastfurnace

a-

concrete Concretewith other

where: Rs = thermalresistance of air space d = thickness of air space = widthof air space E = degreeof exchangethroughradiation hro = €xternalsurfaceresistancedue to radiation for a blackbodv

Mortar(masonrymoftar 250-2000

q!q.p]419l!!s!]}9r) accorqing to DINENISO10456 ?44 Bg1glglggconditions Property Boundary condition | (10"c) _ abcd Referencetemperature 10'C 10'c Moisture

A;.1.;-

u

"U6o

"23,50 aqed

il (23.C) 23"C

23'C

,3zo

aqed

udryis a low moisturecontentattainedafterdrying, u23,50 is a moisturecontentwhich becomesestablishedin equilibriumat 23'C air temperatureand 50% relativehumrdity.

2.6.12 fhermal resistanceR of stationaryair layers- surJaceswith high degreeof glE!lg!! @onofheatfbw R in mrK,A/V ry]m __-. upwaros Horizontal , 0 0,00 0.00 5 0.11 0.11 7 0.13 0.13 10 0.15 0.15 tc 0.16 o.17 25 0.16 0 . 18 50 0 , 16 0.18 100 0,16 0.18 300 0,16 0.18 NC!9.l4q!qdiq1g trel!9lllqy Q_e4!Cl!gq Qylllgelinterpoiation.

Downwards 0.00 0.11 0..13 0.15 0.17 0,.19 o.21

o.22 o.23

2.6.13 Thermalresistancesof stationary, poorlyventilatedand wellventilatedair layersaccordingto DIN EN ISO6946

O p e n i n g< 5 0 0 m m 2p e r 1 m l e n g t h

O p e n i n g > 5 0 0 m m 2p e r ' l m l e n g t h < ] 5 0 0 m m 2p e r 1 m l e n g t h

O p e n i n g > 1 5 0 0 m m 2p e r 1 m l e n g t h

Stationaryair layer

Poorlyventilatedair layer R - halfthe valueof the stationaryair layerbut max.0.15 m2K,4V

Well ventilatedair layer

164

(hu+ 1/2 Eh,o(1+d2lb2- d/b))

R"" = R"i= 0.13 m,l(W

huis as follows: . for a horizontalheatflow: h" = 1.25Wm2Kor 0.025/dW/m2K, whichever is the greater . for an upwardheatflow. hu= 1.95\N/m2Kor 0.025/dW/m2K, whichever is the greater ' for a downwardheatflow: hu= 0.12d 044W/m2Kor O.025/dW/m2K, whichever is the greater whered = thickness of air spacein direction of heatflow. The thermaloptimization of perforatedmasonry of perforaunitsdependson the distribution In comparing diftionsand theircross-section, ferentpatternsof perforations, the proportionof perforations and the thermalconductivity of the Figure solidmaterialmustbe keptconstant. qualities 2.6.15 illustrates thethermalinsulation in clay for variousarrangements of perforations brickswith40% perforations [46].The 1Bsamplesare arrangedin orderof descending thermalconductivity. ln lightweight concreteunitsthethermalconductivity- for the samegrossdensitydependsquitecruciallyon the proportlon of perforations of cells. and the arrangement of Figure2.6.16showsthermalconductivities masonrymadefromthree-and four-cell hollowblocks,as wellas a slottedunitcalculatedaccordingto EN 1745assuming a gross densityof 600 kg/ms.The valuesgivenapplyto unitsmadefromexpandedclay concreteand lightweight mortarLM 36,

Thermalinsulation

Determinationof design values for thermal

2 . 6 .l 4

S m a l lo r d i v i d e dn o n - v e n t i l a t evdo i d s{ a i rs p a c e s )

conductivity

for Thedesignvaluefor thermalconductivity usein calculating thethermalinsulation of is definedfor Germanyon the basis buildings of the practicalmoisturecontentor the moisturecontentequilibrium aI23"Cand B0%relativehumidity. To do this,the practicalmoisture contentor the referencemoisturecontentof thebuildingmaterial mustbe known.Practical moisture contentis understoodto be a quantity which ofwaterinthe buildingmaterial in an adequately dry becomes established structure overthe courseof time.This is causedby waterbeingabsorbedfromthe air (hygroscopicity) and the formationof condensationon surfacesand withincomponents. practicalmoisturecontentexcludes Therefore, moisture whichhas dueto buildingprocesses notyetfullydisappearedand saturationresultingfromprecipitation, risingdampand damThepracticalmoisture conageto the building. tentis definedby the relativecumulativefrequencyof a multitude on as of investigations manystructures as possible.Figure2.6.17 for a building showsthetypicalprogression material. The resultsof measurements of autoclavedaeratedconcretewallsand roofs(see fig.2.6.21) can serveas an examplefor the of externalcomponents dryinggradient [104]. wallswith adequaterainprotection External andpermitting evaporation on bothsidesdry outfaster,The dryingperiodlastsabouttwo yearsunderdifferent As the drying conditions. gradient is considerably influenced by the the weather, theoccupation of the building, of standardof construction and the orientation thewalls,and determining the moisture by removing coresof materialis expensiveand the complicated, a new methodof determining moisture characteristic of a buildingmaterial bywayof its hygroscopicmoisturecontent in a definedclimateis nowbeing equilibrium Moisture absorption at 23'C used(fig.2.6.18). humidityhasprovedequivaandB0%relative We speakthen lentto thefieldinvestigations. of thereferencemoisturecontent,a parameter in Eurowhichhasalsobecomeestablished peanstandards (seetable2.6.10,columns5 and6).Thewatercontentof a buildingmaterial is specifiedeitheras the quantiiyof waterconrelatedto tainedin a massunitof the material, thedrymassas the "mass-related watercontent"u in kg,&g,or as the volumeof watercontainedin a volume unitof the material,relatedto the material watercontent" volumeas the "volume-related y in m3/m3. Themass-related moisturecontentis recommended for buildingmaterials becauseit remainsconstantoverthe entiregrossdensity range. As an example, figure2,6.19showsthe resultsof teststo measurethe sorptivemoistureof aeratedconcreteat an ambienttemperatureof 23'C and B0%relativehumiditv,and

d. -1--

7-

t'tt

b

/"

." Heatflow

for a constantproportionof perforationsand constanttotalweb thick2.6,15 Variationsin clay brick cross-sections ness (heatflow horizontal)[2] Diamonds, offset

Circularholes, parallel

Ellipses, parallel

Delta perforations

Hexagons, offset

Rectangles,parallel+ grip holes

WWWffiffiffi WWWWffiffi ffiffiWWWW Ellipses, offset

Rectangles, parallel

Rectangles,oflset + grip holes

Rectangles,ofl seY"standard"

T-bricks

Interruptedouter weos

K-bricks

Gothic bricks

Meander bricks

"Spring" bricks

Fence bricks

Fineceramic"B" bricks

2,6.16 The influenceof pedorationson the thermalconductivityof lightweightconcreteunitswith grossdensity600 kg/ms

tilml Unit

Thermalconductivity Proportionof Concrete perforations gross density of masonry

B

llLjILlul c

t!l!_[]l C

35 35

kq/m3

929 923 680

0,27 0.25 0.18

Building science

2.6.17 Cumulativefrequencyof moisturecontenl of pumice buildingmaterialsin external walls determinedin 88 samples

2.6.18 Volume-related moisturecontentin relationto relativehumidityfor absorptionand desorption of a calciumsilicateunitwith grossdensity 1720kg/m3,afterKunzel 20

' Abiorption o Desorption

E E p16 c o o o

zo

I

E rr8

3 an o-

a 6 I 64 E

f

o o .F

// I

l

6

b

b cr

_-----t

4

Relativehumidity(%)

Volume-related moisturecontent 2.6.19 Sorbedmoisture(equilibriummoisturecontent) of autoclaved aerated concrete at 20'C and 80% rh in relationto the volume(y) or the mass (u) of the materialdependingon gross density

2.6.20 Percentageincreasein thermalconductivityol autoclavedaeratedconcretedependingon 1.,0,,,, in relationto % by vol. or 1 mass 70,after l6l

10

14

therbetween tig.2.6.20showsthe relationship mal conductivityand moisturecontentderived moisture fromthis.Takingthe mass-related contentas our referenceoointallowsthe useof a surchargeto coverthe influenceof the moiswhichis indetureon thethermalconductivity, pendentof the materialbulkdensityandthe To carryout a thermal thermalconductivity. the userrequiresa thermal insulation analysis, designvaluefor the particular conductivity Thistakes type of masonryconstruction. accountof the type,formand grossdensityof the masonryunitas well as the type of mortar. The thermalinsulationpropertiesof different typesof masonrycan be determinedfrom tablesaccordingto EN 1745or by measuring basedon the samplesof wallor by calculation materialparameters[3]. To take intoaccount the influenceof moistureon the thermalconductivity,the referencemoisturecontentsand valuesFmgivenin table moisture correction 2.6.23applyin Germany. Morefavourable valuesnotcontainedin thetablemavbe verifiedexperimentally. Thermal performance of external walls

10 o

I

\o

B

c

;9

!

r>Q.

o A a

c o

o 6?

=

t

o

a c^

l

m

-:-\

s6

o

0 300

400

500

600

700

800

0.08 0.10

900

0.14

0.16

0.18 0.20

Thermalconductivity(W/mK)

Moisturecontent(%) 2.6.21 Drying-outof autoclavedaeratedconcreteexternal components(wallsand flat roofs)plotted againsttime [3]

0.12

2,6.22 Ventilatednaturalstonefacadesand lightweight curtainwalls;increasein thermaltransmittance of wall in relationto numberof fixingsand fixing material AU (WmzK)

o4

E >1'

plasThethermalresistance R of single-leaf teredexternalwalls,single-leafexternalwalls or with internalor externalthermalinsulation, insulatwin-leaf wallswithor withoutadditional tionis calculated by simplyaddingtogether layers.As an the R-values of the individual figure2.6.24showsa plastered example, comwallwitha thermalinsulation single-leaf positesystem.lf the insulationis attachedwith fixings,additional heatlosses mechanical occurdependingon thetypeof fixing,Based on experiments and numericalpararneter studies[6, 205],the heattransferfor a component(including thethermalbridgeeffect) in a simplified estimation can be represented methodas follows: . by addingthe increase AU to thethermal valueU for the undisturbed transmittance sectton U"=U+au

!-

. by a percentageincreasein the thermal transmittance valueU c o O Aj l 6 '6

U"= U(t+-rOO)

02468

01234

Time (years)

No. of fixingsper m2 Natural stone facade Lightweightcurtainwall o

The initialprogressionof the given range stemsfrom measurements on externalwalls at the FraunhoferInstitute'sopen-airsite (lowerlimit:externalwall, evaporation possibleon both sides;upper limit:outerface sealed, evaporationonly possiblevia innerface). o externalwalls o flat roofs representmeasurements of actual buildings.

166

. by addingthe increasein the conductance of a componentby meansof the discretethermaltransmittance 1 L= IUiA,+ L1, Thefirstmethodwith a surchargeAU was first usedin the European standardEN6946.The valuesgivenin table2.6.25applyto correction the varioustypesof anchorsusedfor fixing thermalinsulationcompositesystems.A masonrysubstratebehavesslightlybetterthana

Thermalinsulation

concreteone.Thetype of renderinghas practicallyno influence on the outcome.Thethermal materialand its conductivity of the insulation thicknesshaveno effecton the additionalheat givenper losswhenaddingAU.TheAU-values anchorcan be simplyaddedtogetherfor the particular application, slncein the mostunfavourable situation the anchoronlyhasan effectwithina radiusof max.250 mm aboutits axis.Influences of AU < 0.002can be ignored the additional heatlossliesbelow because 3o/o.

Atjust1%the influence of thethermalbridges for mechanical fixingsyscanbe neglected if the plastic temsusingplasticrails.However, railsarereplacedby aluminium ones,this results in a considerable of AU = surcharge 0,05Wm'?Kfor horizontalrailsfixedto the loadbearingsubstrateat 500 mm centres. insulated wallwitha Inthecaseof a thermally ventilated external claddingmadefromany oneof a numberof differentmaterials,the cladding fixingsin thewallact as thermal Theireffectdependson the following bridges. influences: . material of thefixings ' numberof fixingsper unitsurfacearea . typeof wallmaterial. Timbersupportingconstructions with vertical andhorizontal battensfor carryingthe thermal insulation andthe claddinghaveonlya relativelysmalleffecton the heattransfer.Thethermalinsulation can be of suchconstructions calculated accordingto DINEN ISO6946.One particularly unfavourable casewitha highnumfacadewitha berof fixingsis the ventilated claddingof naturalstone.The naturalstone slabsareusuallyfixedto thewallby meansof The and retaining anchors. supporting absoluteincreasein the thermaltransmittance causedby the anchorsdoesnotdependon thethickness of the insulation andthetypeof hasno influence stonebasically on the heat transfer. On theotherhand,replacinga conwallwithoneof masonry creteloadbearing reducesthe influenceof the anchorsby 4Oo/o. Thereis a linearcorrelation betweenthe absoluteincreasein the heattransferand the numberof anchorsper unitsurfacearea(see fiq.2.6,22). The influence of thethermal steel bridgesis cut by halfwhenstainless anchors areused.lf the naturalstonefacadeis replaced ventilated by a lightweight cladding withothertypesof fixingto the loadbearing wall,surprisingly, the influence of the anchors remains the same.Theuseof a olasticunder lay("Thermostop") betweenbracketand masonry bringsabouta clearreductionin the thermalbridgeeffect,but a thermalbreak attachedto the cold side of the brackethardlv hasanyeffect. planninginstrument An important thesedaysis the"Determination of thethermalinfluences of thermalbridgesfor curtainwallventilated facades"[163].Thediscretethermalbridge

lvloisturecontentsand conversionfactorsfor moisturecontentaccordingto draftstandardEN 12524table 2, and moisturecorrectionfactor F- accordingto draft standardEN 10456 Moisture Conversionfactorfor Moisturecontentat lvlaterial correction moisturecontent 23 "C. 80% rh factor Fkgkg Autoclavedaerated concrele Lighh//eight concrete with pumice Lightweightconcrete with expandedclay Clay C a l c i u ms i l i c a t e lvlortar

1.2 1.15

4

1.08

0.03 10 10 4

o.o12 0.o24 0.06

1. 1 3 1.27 1.27

2,6.24 Exampleof calculationfor externalwall of plasteredsingle-leafmasonry Layer

Thicknessof layerrn m 0.015

R m2K,i1,{ 0.04

IR W/mK

0.35 Internalplaster 6 C a l c i u ms i l i 0.99 cate masonry 5 0 . 1 7 5 Bonding 4compouno R i g i de x panded polystyrene foam 3 0 , 1 2 0 Textured 1rendeflnq ThermalresistanceR = X d/)\. = 3.22

0 , 18

3.00

Thermaltransmittance U = 1 / ( 0 . 1 3+ 3 . 2 2+ 0 . 0 4 )= 0 . 3 0W m ' z K

1 , 5 -- 1 2 Tl

17.5 r-l

2.6.25 Heat lossesvia varioustvoes of anchors Type oI anchor Facadeanchorwith disc and steelscrewwith neao anchorwith steelscrew electrogalvanized with plasticcoatinq

aK per ancnor W/m'?K

Dia, of anchors mm

0.008 0.004

0.002

Facade anchor with V4A stainless steel

screwwith Facadeanchorwith thermalbreak

2.6.26 Recommen.qed valuesfor totalenergytransmittanceof transparentcomponentsto DIN 4108 part 6 Totalenergytransmittance Transparentcomponent YI

S i n g l eg l a z i n g D o u b l eg l a z i n g Heat-absorbingdouble glazingwith selectivecoating Tripleglazing,standard Tripleglazingwith 2{old selectivecoating glass Solar-control Translucentthermalinsulation

0.87 0.76 0.50 to 0.70 0.60 to 0.70 0.35 to 0.50 0.20 to 0.50

Translucentthermalinsulation T h e r m ailn s u l a t i o n1,0 0 - 1 2 0m m ; 0.8 Wm'?K< U" < 0.9 Wm'?K Absorbentopaquethermalinsulationwith s-[lglelayerglass cov

035 to 060

-

aPProx.Or]0

167

Building scienee

2.6.27 Rangesof standardthermaltransmittanceU for various external masonry walls

U-value

System

w/m2K

lossvaluec in W/K or the thermalbridgesurchargeAU in Wm2Kis specifieddependingon the construction of the supportsystemand the thermalresistanceof the loadbearingconstrucThe tion (influence of transverse conduction). effectof a thermalbreakis shownin fi7.2.6.28, a thermallyadvantageous supportingconstructionin fig.2.6.29.Figure2.6.27is an overview valuesfor a numof the thermaltransmittance ber of differentwall constructions.

0.30- 0.50 Windows

0.30- 0.45

S

NR\ t tM_I--1

t)\R[ t\Til \T'E \E--f--__-ll

1 0.20- 0.40

Thewindowas the "thermalhole"in the buildingenvelopeis nowa thingof the past.Techglazing nological in insulating developments systemshaveset standardsin the energy assessments of heatedbuildings. Thereduction in transmission of heatlossesand maintenance for the a sufficienttotalenergytransmittance passiveuseof solarenergymeanthatwindows to the heatgainduringthe heating contribute season.However,the areasof glazingdo have theirlimitsin termsof thermalinsulation during the summer,whenthey can leadto uncomfortably high interiortemperatures. Thethermal transmittance U* of a windowdependson: ' the distancebetweenthe panes ' the numberof panes . the emissivityof the glasssurfacestowards the cavity . the gasfillingin the cavitybetweenthe panes ' the hermeticedgesealof insulating glazing ' the materialof the frame.

0.25- 0.40

0.30- 0.50

0.40- 0.50

168

The thermaltransmittance U* can be taken fromtablesaccordingto DINEN ISO10077 part 1 (table2.6.30)for constantframeproportionsof 20 or 3O%,dependingon the glazing (U")andthetypeand designof theframe(Ur), orijeterminedby a simplearea-basedassessmentof the U-valuesfor glazingand frame includinga surcharge for the glasssealaround the perimeter. Timberand plasticframesprovidegoodthermalinsulation; the insideand outsidesurfacesof metalframesmustbe carefullyseparated(thermal break).Wideningthe cavitybetweenthe panesonly improvesthe Uo-value up to a certainwidthdependingon thb type of glass(forair about20 mm). lf this width is exceeded,thenthe improvement to the thermalinsulationpropertiesis counterBy employing noble actedby convection. gases(argon,krypton,xenon),we can exploit theirlowerthermalconductivity(comparedto air).The heattransportby way of radiation characterized by the emissionbehaviourof the glasssurfacescan be drasticallyreducedby usinglow-Ecoatin.gs. The development of lowE glazingbeganwith sputtered,laterpyrolytic coatingsand an airfillingto the cavity;this broughtUn-values of 1.8Wm'zK.Today,double glazingwith magnetroncoatingsand noble gasfillingsreachUg-values of 1.1Wm2K.And moderntripleglazingsystemsbasedon silver

coatingsand noblegasfillingshavealready reachedpeakvaluesbetween0.7 and 0.4 W/m2K. of the windowfor solarradiaThe permeability tion is expressedby the totalenergytransmit: tanceg. Thiscorrespondsto the percentage proportionof ineidentradiationthat passes of the buildthroughthe glazingintothe interior ing.As the glazedsurfacesare generallynot positioned perpendicular to the solarradiation and so part of the solarenergyis lostthrough reflectionat the pane,the totalenergytransmittanceis reducedby 15%.Furthermore, permanent shade,frompadsof the building, windowftames buildings, trees,neighbouring etc.,as wellas the degreeto whichthe solar energysuppliedis usedmustbe takeninto solarheatgains.lf accountwhencalculating no individualfiguresbasedon measurements are availablefor the totalenergytransmittance, the designvaluesgivenin fig.2,6.26maybe used.Thesevaluescoverthe lower,i.e.less of insulating favourable,rangeof permeability glazingwithrespectto the solargainsin the heatingseason.Figure2.6.31showsthethermal balanceof two windowswith doubleand tripleglazingduringthe heatingseasonin a (10"C heatingthresholdreferenceenvironment temperature, degreedaysfactor2900)com' oaredto the heatlossesof a well-insulated are achievedby externalwall.The Un-values usingcoatedglassesand gasfillingsto the cavity.lt can be seenthat doubleglazingwith but less of higherUo-value a combination has favourabletotalenergytrahsmittance advantageson the southernside but for other comorientatjons exhibitsslightdisadvantages paredto the tripleglazing.The latteris not usedso widelybecauseof the considerably higherweightof the glass.In the searchfor solutionswith evenlowerthermaltransmittance values,countersash and coupledwindows in certaincircumoffergood alternatives stances.The much betterinsulatedexternal wallsof modernbuildingsrenderit necessary to pay specialattentionto the detailat the junction betweenthe windowand the wall,or the positionof the windowin the wall.Poordesign can havea considerable or workmanship effecton the heatlosses.Variouswindow in monolithicmasonrywallswith arrangements external,cavityand internalinsulationhave with respectto theirheat beeninvestigated lossesvia the windowrevealsand masonry [45].Figure2.6.32showsthe bestpositionsfot: windowsin differentmasonrywall constructions. windowsill, 2 contains DIN4108supplement revealand headdetailsfor monolithicmasonry or masonrywith externalor cavityinsulation. An extractshowingdetailsfor a wallwithcavity insulation is shownin fig.2.6.33.

Thermalinsulation

Translucentthermal insulation (Tl)

2,6,28 Thermalbridges in ventilatedcurtainwall facades;influenceof thermalbreak betlveen

aluminiumbracketand fixinosubstrate Incontrast to normalopaquethermalinsulation attached to ihe outside,Tl allowsthe incident Discretethermalbridge loss coefficient1 (W,4() Substratefor fixings solarradiation to passthroughthe insulation Bracketfixing point o.12 material. Theradiation is thenabsorbedand 0 , 11 Thermalinsulation intoheatat the loadbearing wall.As converted 0,10 Tl functions as thermalinsulation, the heatloss Bracketslidingpoint 0.09 to theoutsideis considerably impededand the 0 . 0 8 majority of the solarenergyis conveyedas o.o7 T-sectionsupport heatto the interiorbehindtheTl wall.As fig. 0,06 2.6.34shows,conventional, opaquethermal hermalbreak 0,05 insulation converts the incidentsolarradiation 0.04 intoheatat the externalsurfaceand thenradi0.03 with thermalbreak atesthe majorityof it back to the externalenvi0.02 proporlion ronment. Onlya negligible of the incidentsolarradiation is transmitted 0 . 0 1 absorbed 0.00 through thewallto the interior. Butthewel> o.7 0.6 0.4 0,5 0.2 0,3 0 0.1 comepassiveuseof solarenergyduringthe ThermalresistanceR of fixing substrate(m2K,AiV) wintercan leadto undesirable heatgainsdursteelwith ingthewarmermonthsof the year.The lower 2.6.29 Thermalbridges in ventilatedcurtainwall facades;rail systemsof chromium-nickel good thermalperformance thethermalconductivity and storagecapacity 0.03 of theabsorbentsurfaceof a Tl wall,the hotter /,/ Substratefor fixings it becomes uponthe incidence of solarradiation.Thismeansthatthe absorbent surface thermalbreak behinda Tl wallcan reachoeaktemoeratures Facadefixingwith of 100'Cand morewithverylightweight base plate and perforatedplate masonry comparedto maximumtemperatures Serratedrail of 70'Cfor veryheavymasonry.The transluSpacerwith centthermalinsulation mustbe providedwith thermalbreak for suchsituations. sunshading ThemoreintenThermalinsulation sively thesuncan shineon thefacade,the 0.0] higher the heatgainsof a Tl wallare.This meansthatthe energygainsare greatest for a southorientation, the lowestfor a nodhorientation. Theheatlossesduringthe heatingseasonoutweighthe benefitsin the caseof a nodh >0.7 0.5 0.6 0.4 orientation. Tl surfacesfacingeastand west (m2K V) R of fixing substrate Thermal resistance exhibit an evenenergybalance.Cleargains havebeenrecordedfor south-facing Tl surfacesduringthe heatingseason.Thethickness windows to DINENIS9llSZZIe4 1 2 , 6 , 3 0 Thermal transmittance_oJ of themasonryhas no significanteffecton the Type of gains when energy of a Tl wall,Nevertheless, glazrng irfr.,x Wm2K planning a Tl buildingit is important to conqa 30% Proporlionot tra 3.8 3,4 2.6 3.0 r. 8 2.2 1. 0 1.4 siderthethickness of the masonrybehindthe 5.1 4.9 4.6 4.8 4.5 4.5 5.7 4.3 translucent thermalinsulation as thisinfluences S i n g l e -s.t thedelaybetweenmaximumincidence of solar Doubiit--3.6 3,5 3.4 zg 3z n z8 ffi 3.3 3.5 radiation 3.2 andthe heatbeingpassedon to the glazrng 2.9 3.1 2.6 2.7 2.8 3.1 3.3 3.1 3,2 2.8 3.0 2.7 2.9 2.4 2.5 interior. Thisdelayis about4 hoursforwalls 3,1 3.2 2.8 2.9 2.5 2.6 2.3 2.4 2.7 175mmthick,about6 hoursfor walls240mm 3.1 2.8 3.0 2.6 2.7 2.3 2.4 2.5 2.2 thickandaboutB hoursfor walls300 mm thick, 2.9 2.8 2.6 2.7 2.3 2.4 2.1 2.2 2.3 2.8 2.7 2.6 virtually 2.3 2.4 irrespective of thetypeof wallmaterial, 2 2.2 1,9 2.7 2.5 2.3 2.4 2.1 1.8 1.9 2.0 Consequently, thetimeat whichthe heatis 2.5 2.4 2.3 2.0 2.2 1.8 1.9 1 . 7 1 , 6 passed on to the interioris decisivefor the 2.4 2.1 2.3 1. 9 2.O 1. 6 1.7 l.c 1. 5 comfortof the user.Thethermaland energy 2.2 2.O 2.1 1.9 1.6 1.7 1.4 1,5 1.3 2.O 2.1 1.9 1 1.3 1.5 effectsand the influenceof climate,material 1.2 -2e 1 ..77 L6 ze 2.7 2.4 2.5 2.1 2.2 2.3 2.0 parameters and construction detailshavebeen Triple 2.8 2.5 2.6 2,4 glazrng 2.1 2.2 1.9 2.0 2.1 investigated in a projectsponsored by Ger2.6 2.5 2.4 2.0 2.1 2.3 1.7 1.8 1.9 many's FederalMinistry for Research and 2.5 2.4 2.1 2.2 1.8 1.9 1.6 1.7 1.7 2.4 2.3 2.0 2.1 1.7 1, 9 LC 1. 5 1, 6 Technology [63]. 2.2 2.1 1.9 2,O 1.6 1.7 1.4 1,5 1,3 Astheuseof translucent thermalinsulation 2.1 2.0 1.9 1.6 1.7 1.2 1.3 1.5 1.1 frequently leadsto excessive heatwhichcan2.0 1.8 1.6 1,7 1.4 1.2 1.3 0,9 notbe used,the cost-benefit ratiocan be con1. 8 1.7 1.5 1,6 1.3 1.1 1.2 o,7 0.9 1.6 1.7 1.4 1,3 1.0 1.2 0.8 0.9 siderably influenced in individual casesby pro9,5 Note:Calculatedusingy-valuesfrom appendixE. Valuesfor windowswhoseframe proportion* 30% shouldbe vidingonlya partialcoveringof translucent determinedus.lllg_the equationsin the main.partof this standaF, thermal insulatlon. Theareaof translucent

7.O o. l

4.4 4,3 4.1 4.0 3.9 3.8 3.6 3.5 3.3 3,2 3,1 2,9

3.7 3,6 3.4 3.3 3.2 3.1 2.9 2.8 2.6 2.5

Building science

2 . 6 . 3 1 T h e r m abl a l a n c e o f w i n d o w s o v e r a h e a t i n g s e a s o n f o r a r e f e r e n c e l o c a t i o n i n G e r m a n y KWh/HPm

2

!

DoubleglazingUs=1.2 9 = 0 . 6 5 Tripleglazing Us=0.8

% 20

South

EasWVest

9=0.5

E x t e r n aw l all rr_^e ascompanson "-"."

I

Solar gains of opaque external walls

Opaque

2.6.32 Positionof window in wall for differenttypes of walls + smallheatflow via windowreveal - large heatflow via window reveal

Type of externalwall accordingto table 1 Positionol windowin watl

Monolithic

Externalinsulation

Cavityinsulation

Internalinsulation

l7t4t

tffi Outside

w f././/-

T

Central

lnside

170

ruw3wl

is typicallybetween10 and thermalinsulation ln choosing of the totalareaof insulation. 3Oo/o aspects, whichareasto cover,architectural the orientation of the facade,the planneduse of the interiorand the amountof spaceavailableon thefacadeall playa role.A solarenergy systemconsistingof a translucentlayerof polycarbonate witha capillarystructureand a finalcoatingof translucentplasterhas proved practicable option[204]. to be an especially One importantadvantageof the systemis that in summera largepartof the incidentsolar radiationis reflectedat the surfaceof the plaster,and so expensive and translucent shadingsystemsaregenerally troublesome unnecessary.

m +ffi

Externalcomoonentsabsorbdirector diffuse Thus,the outerlayers incidentsolarradiation. of the componentheatup firstand the heatis conductedto the insideof the component. Thisprocessreducesthe heattransferthrough the externalcomponent.The heatgaindue to solarradiaradiation deoendson the available and colourof tionand henceon the orientation anyshadingto surfaces, the component's thosesurfacesand the externalsurfaceresisheat in transmission tance,Thereduction losseswhichcan be achieveddueto the absorptionof radlationby an opaqueexternal to the U-valueof the exwall is proportional hasone ternalwall.Whetherthe construction likewise, or morelayersis virluallyirrelevant; conthe sequenceof layersin a multi-layer struction. Theannualsolarnetheatgainsfromopaque without sectionsof the buildingenvelope onlya constitute thermalinsulation translucent fractionof the totalsolarheatgainsand are partlyoffsetby the radiationheatlossesfrom they sky.Therefore, the buildingto a cloudless can usuallybe ignored.Table2.6.35contains solargainfactorsfor commonexternalwalls. of an externalwall is Thethermaltransmittance influonlyreducedby 2-12%by the radiation The encefor averageclimaticrelationships. for BuildingPhysicshas Institute Fraunhofer in a computerreachedsimilarconclusions with studyon buildings assistedexperimental walls[198]. external monolithic and multi-layer

Thermalinsulation

Heat storage

Theinterior heatsup and coolsdown,the sun shines on theoutsideand rapidchangesto theairtemperature take placeon bothsidesof components. Theseeffectsleadto temperature changes andchangesto the heatflowswhich cannotbe takenintoaccountby the thermal resistance R or the thermaltransmittance U. ln thesecasesthe heatstoragecapacityof the materials andcomponents in conjunction with thetimeplaya decisiverole. Fora mathematical withnumerical analysis methods we requirevariables derivedfromthe specific heatcapacity, thethermalconductivity,thegrossdensityand thethickness of the materials concerned.The heatstoragecapacity Q",i,e,theamountof thermalenergyin J/m2K storedin 1 m2of a slab-like component of thickness d in m madefroma materialwith densityr in kg/m3for a 1 K temperaturerise,in a homogeneous is givenby construction Q"=cxPxd Thepropagation of a temperature zone in a material is describedby its thermaldiffusivitya in m7s.As the a-valueincreases,so the temperature changein a materialspreadsfaster. Thethermaldiffusivityis derivedfromthe thermalconductivity I, the specificheatcapacityc andthedensityp of the material concerned:

relatively small.Theoretical studieshaveproTherefore, the ducedthe sameresult1741. questionof whetherthe heatstoragecapacity of external compoor thethermalinsulation nentsis moreimportantfromthe pointof view it definitely of savingenergycan be answered: Theimportance dependson thermalinsulation. of the thermaltransmittance as the basisfor heatlossesthrough calculating transmission external wallsis undisouted. Studiesof buildingswiththe mostdiverseexternalmasonry wallshaverevealed thatdespiteseverely flucquasistatuatingexternalclimaticconditions tionaryheatflowsbecomeestablishedafter,at most,oneweekandthe U-valueadequately the heatlossesthroughthe opaque describes external surfacesof a building[2]. However, heavycomponents, whicharethussuitedto storingheat,do havea positiveeffecton the internal climatebecausetheycooldownslower whenventilating the interior or afterswitching the interior offthe heatingand hencemaintain air temperatureat a comfortablelevelfor a longerperiod.Theamountof heatlostthrough however, ventilation and transmission remains, the sameas for the lightertype of construction.

We mustdistinguish betweentwo opposing phenomenawith regardto the effectof the heatstoragecapacityon the annualheating requirement. Theheatgainsdueto internal heatsourcesand incidentsolarradiation can )r than be betterused by the heavyconstruction A_ oxc the lightweight construction becauseoverheating of the interioris considerably lowerin the Thethermal diffusivity of buildingmaterials lies former.Thiseffectis rewardedwith a better intherange0.4to 1 x I 0 6 m7s dependingon the behavuseof the heatgains.In contrast, bulkdensity(timber= approx.0.2x 10-6m7s, is more iourof the lightweight construction steel= approx,2.0x 10-6m7s).Theheatpene- favourablethanthe heavyconstruction in the trationcoefficient reduction of the materialconcernedis caseof a night-time temperature thegoverning variablewhenassessing the becausethe internal airtemperatures canfall behaviour of materialssubjectedto briefheat morerapidlyand hencethe heatlossesare flowprocesses suchas the heatingand coolsmaller.lt is notpossibleto makegeneralized ingof walls.The heatpenetration coefficientb statementsas to whichtype of constructionis is derivedfromthe thermalconductivity1.,the betterin termsof heatingenergyconsumption specificheatcapacityc and the densityp of becauseof the opposingeffectsof a night-time thematerial : concerned temperature reduction and overheating. Duringthe warmermonthsof the yearthe heat O=yTx p x c storagecapacityof the internalcomponentsof influence on a buildingexertsa compensating gradient.lf the heat Theb-values of somebuildingmaterials the internal are airtemperature givenintable2,6.36.Figure2.6.37showsthe fromthe sun is storedin the components heating andcoolingbehaviour for a changein beforebeingradiatedto the internal air,in interior airtemperature of 15 K for two different summerwe enjoya pleasant, balancedinternal wallconstructions with approximately equal climateevenwhencoolertemperatures thermal resistance. Rapidheating-up of the alreadyprevailbutside.DINEN 13786stipuwallsis desirable fromthe pointof viewof valuesrelatedto the latescharacteristic - withthe heatingoperatedbriefly, comfort of completecomdynamicthermalbehaviour ponentsand specifiesmethodsfor theircalHowever, the lightercomponentcoolsdown quickerafterswitchingoff the heating.Practiculation. calinvestigations Thecharacteristic of the influenceof the heat valuesdefinedin the stanstoragecapacityall leadto the sameresultfor dardcan be usedas productspecifications thatthe influenceof the heatstoragecapacity, components or for calculating especially thatof external walls,on the energy 'the internal temperature in a room, . the dailypeakperformance consumption for the heatingof a buildingis and the energy

2.6.33 Favourablewindowpositionto DIN 4108 supplement2 to reducethermalbridge effect (fulljill cavitywall)

2.6,34 The functionof translucentthermalinsulation ^^m^.r6d +^^n.^t 'a thermalinSUlation Transparent I n c i d e nst o l a r radiation

Heat radiation

I n c i d e nst o l a r radiation

Heat radiation

Buildingscience

2.6.35 Solargainfactorsfor commonexternalwalls subiectedto averaoeclimaticconditions[2131 Orientation Commonexternalwall Liqhtcolour Dark colour South 0.04 o.12 Easywest 0.03 0,07 North 0.o2 0.06 2.6.36 Heat penetrationcoefficientsfor some building materials Buildingmaterial Heat penetrationcoefficient J/sosmrK Normal-weight concrete dependingon grossdensity Lightweightconcrete dependingon grossdensity Clay brjcks Timber Foamedplastics

1600 to 2400 250 to 1600 1000 to 1300 500 to 650 30 to 45

2.6.37 Chronologicalprogressionof interiorsurface temperatureOoifor various externalwalls with approximatelyequalthermalresistancesafter increasingor decreasingthe internalair temperatur€OLiby 15 K ('C) [62] R = 1 , 5 0m 2 l ( W Wall 1

- 24Omm aerated concrete 500 ko/m 3 i l-

i, = 0.16w(mK) ooi

I

ou = 5'c

Yri

tc O o

Ern o o

E o

0

5 10 Heatingup (h)

F = 1.55 m2KAV

p 60 mm polystyrene, 30 kg/m3 l, = 0.040 W(mK)

Wall 2

.

flf or' = 5"c

tc (_l o i.n o o E o

F ' c-

't72

100 mm normal-weight concrete 2500 kg/m J

lt ^=21w(mK)

[1 Ln H Is.'

requirement for heatingor cooling, . the effectsof intermittent heatingor cooling.

L = x U i x A , + x Y o xl ^ + E 1 ,

where: L thermalconductionin W4( of buildingenvelope Ui thermaltransmittance Thermal bridges componenti in Wm2K Theseare weakpointsin the thermalinsulation for U, of the buildingenvelopeat which- compared Ai surfaceareaapplicable therof continuous Y., thermaltransmittance to undisturbed, neighbouring sectionsof the - additional malbridgek in WmK heatlossesand lower comoonent for Y^ lengthapplicable 'K internalsurfacetemperatures occur.Various of discretethermal typesof thermalbridgesare possibledepend- x1 thermaltransmittance bridgej in Wl(. ing on theway in whichtheyareformed: . Geometric thermalbridgesensuewhenthe Y is normallytaken The thermaltransmittance heat-absorbing and heat-radiating surfaces The examples fromthermalbridgecatalogues. of the comoonentare of differentsizes.The of buildingdetailscontainedin thesecataclassicexampleof a geometricthermal basedon fixedparameloguesare essentially wall. bridgeis the cornerof an external . Material-related andare and materials) ters(e.9.dimensions thermalbridgesdependon The lessflexiblethancalculations. therefore the construction of the buildingandthe of components catalogueexamplesoftendo not correspond arrangement and combination with materialsof differentthermalconductivi- exactlywiththe componentbeinginvestigated. the useof Y-valuesfromcataConsequently, ty. Typicalthermalbridgesof thiskindare aboutthose loguesleadsto uncertainties roofbearings,parapets,balconyfloorslabs the Y-valuefroma catawalls. details.Nevertheless, and columnsin external . Detail-related loguecan be used,providedthe dimensions thermalbridgescan ensuein comoonents dueto mechanical connections and the thermalpropertiesof the catalogue whichpenetrate or bypassthethermalinsula- examplearesimilarto thoseof the building exampleis less tion.Theseincludeanchorsin concretesand- detail,or the catalogue in thermaltermsthanthe building favourable wichwallsand multi-leaf walls,and all condetail.The Y-valuesin a thermalbridgecatastructions in metalandtimber. loguemusthavebeenderivedfromnumerical calculations accordingto DINEN 10211parI2. for avoidingor reducingthermal Measures Thermalbridgecataloguesoffersolutionsto bridgesare certainlynecessaryto avoidcondetailsfrom basementto roof- for wall,winand such densation on internal surfaces, dow,floorand balconyjunctions(seefig. measuresare generallytaken.However,the points 2 contains with 2.6.38),DIN4108supplement remaining in energyterms weak examplesfor thermal designand construction higherheatlossesare usuallynottakeninto accountwhenassessingthermalperformance bridgedetails;the masonrydetailsinclude junctionsfor monolithicexternalwallswith To andthe heatingrequirement of a building. Figure2.6.39 and cavityinsulation. someextentthe additionalheatlossesvia ther- external showsthe junctiondetailsfor groundslab, mal bridgesare balancedby the fact thatthe basementroof (groundfloor),upperfloorslabs transmission heatlossesof a buildingare caland flat roofwith parapetfor a monolithicexterculatedwith referenceto the outersurface, nal masonrywall 365 mm thick.A balconyfloor which is too large,particularlyin the caseof As the slab projectingfromthe structureacts likea thick,monolithicmasonryconstructions. coolingfin owingto the increasein the external standardof thermalinsulation of the building enveloperisesand the thermaltransmittance surfacearea;figure2.6.40showshowthe balconyjunctioncan be thermallyisolatedfrom valuesdrop,so thethermalbridgesplayan is the floorslab.The layerof thermalinsulation role.Therefore, the increasingly significant only penetratedat individualpointsby the reinincreasedheatlossesmustbe investigated at the heat- forcingbars.Thiscutsthe thermaltransmitthe planningstagewhencalculating This tanceY by 50% comparedto a continuous ing energyrequirement for the building. can be done in differentways.Thermalbridges concreteslab.A steelcurtainwall construction due to the structureitself,e,g. edges,corners, connectedto the floorslab by a tensionrod exhibitsa similarreductionin thermalbridge roofbearings, balconyfloorslabsetc,,can to the top losses.Applyingthermalinsulation only be calculatedaccuratelywiththe helpof balconyslab and bottomof the cantilevering computertechniques.However,for the presuccess.In no worthwhile liminary designof a buildingand assessment broughtpractically of the energyeffectsof the buildingenvelope, termsof the thermalbridgeeffectof a whole detailsfor baleonyjuncvarietyof construction it mustbe possibleto estimatethe effectsof single-leaf tions,thereis no differencebetvveen thermalbridgeswithoutmajormathematical composite walls,wallswiththermalinsulation analyses.Withthe helpof correctionvaluesto externalwalls. take intoaccountcontinuousand discretether- systemand multi-layer malbridges,DINEN ISO14683givesthethermalconduction of the buildingenvelopeas

Thermalinsulation

Thethermal influence rangeof thermalbridges canleadto noticeablylowersudacetemperaturesontheinsideandto condensation, which mayleadto the growthof mould.Specifying theinteriorsurfacetemperatures in "C deter- to a limitedextent- the additional mines stioulation of external and internal airtemperature. As verydifferentboundaryconditionsmay be chosen depending on useand meteorological circumstances, the surfacetemperature is used i na d i m e n s i o n l ef os rsmb y D I NE N I S O1 0 2 1 1 part2 according to thefollowingdefinition: f * " ,= ( O "-1O e ) / ( O-iO " ) where: f*., temperature factorat locationof thermal bridge Osi internal surfacetemperature oi internal air temperature fl externalair temperature. ToavoidthegroMhof mould,accordingto DIN4108part2, the minimumrequirement fRsi > 0.70mustbe fulfilledassumingan internal air temperature of 20"Cand 50% relativehumidity foran externalair temperature of -5"C* a not infrequent occurrence in Germanyunderaveragemeteorological limits.Inthiscontextthe minimum thermalresistancefor an external wallR = 0,55m2KAfimustbe increasedto R = 1.2m2KMin orderto alsomaintain the temperature factor0.70at the cornersof external wallsaccordingIo 2.6.41assumingan internal surfaceresistanceR"i= 0.25.This meansmaintaining an internal surfacetemperatureof O"i> 12.6'Cfor the saidlimits.As a rule,thestipulation in DIN41OBpart2 thatall constructional, form-related and materialrelated thermalbridgesgivenas examplesin DIN4108supplement 2 canbe regardedas providing adequate thermalinsulation formsa simplecriterion for the avoidance of mouldfor thedesigner and operatorof a building.Inthe caseof thermalbridgesin components adjoiningthesoilor unheatedbasementroomsand buffer zones,we mustassumethe conditions g i v e ni nf i 7 . 2 . 6 . 4 2 . fhe establishment of thermalbridgescan be carried outby experiment or by analytical means. Thesimplestmethodis the determinationof the internalsurfacetemperatures in the regionof a thermalbridgeby way of discrete measurements and referenceto the temperaturelimitson bothsidesof the externalcomponent.Thermographic techniques involvethe useof an infraredcamerato providea thermal imageof theexterior of a buildingelevation or theinternal surfacesof individual rooms.This methodsuppliesimportantinformation about thecondition and qualityof thermalinsulation. Defective workmanship or the successof upgrading the insulation to a buildingcan be madevisible.However, an infraredphotograph cannothelpus to makequantitative statements

aboutthe extentof thermallosses.Temoerature distribution and heattransfercan be determinedfor faithfulreplicasof components in laboratorytestsaccordingto DIN EN ISO8990, in whichthe component is incorporated as a oartitionbetweentwo soacesat differenttemperatures.The mathematical determination of the effectsof multidimensional thermalbridges is carriedout by calculating thetemperature zoneand heatflowusingthe numerical solutionof thethree-dimensional thermalconductionequaticn.lf adequatefor the particular plane for furo-dimensional case,the calculation relationships is carriedoutand,in the.caseof clearthree-dimensional temperature and heat flowzones,extendedto three-dimensional slruclures.

2.6.38 Some detailsused in a thermalbridge catalogue (Hauser)for specifyingY- and f-values

Walljunction

Wndow junction

Floorjunction

Balconyjunction

2.6.39 Junctiondetailsfor a single-leafexternalwall a c c o r d i n gt o D I N4 1 0 8s u p p l e m e n2t

Building science

2.6.40 lmprovingthe thermalperformanceof balcony floor slab junctions

+

= o.as 7f n",

2.6.41 The temperaturefactor at an e)iternalwall corner as a function of the thermal resistanceof the externalwall for two differentthermal transmittancevalues

36.5 cm

ed

o

H 0.8 o

= 6 @ o

E o

i7 ".,

F

0.6

R Thermal resistance

174

Airtightnessl

for thermalinsulation As the requirements of the building increase, so the airtightness envelopebecomesmoreand moreimportant. is necessary A highdegreeof imperviousness in orderto reallyachievethe desiredreduction and avoiddamin heatingenergyrequirement ageto the buildingas wellas a dropin the leakagefrom standardof comfort.Uncontrolled the buildingwrecksall othermeasuresfor Therefore, thethermalinsulation. increasing partialoptimization, likeminimizing U-values withouttakingintoaccountsuch leaks,are totallyineffectivein practicalterms.The airtightnessof a structuremustbe considered and independently of the exchangeof internal externalair.Thisexchangeof air is necessary to maintain a hygienicinternal climateand is takenintoaccountwhencaiculatingthe heatby way of the ventilaing energyrequirement tion heatlosseswith a definedair changerate. naturally Theair changerateis accomplished by openingthe windowsor by way of mechanical ventilation systems.So, leaksin external componentsrepresentadditionaluncontrolled ventilation heatlosseswhichcan be avoidedor at leastminimizedaccordingto the stateof the an. A non-airtight buildingenvelopeusuallyresults in severalunwantedeffects:

of the internal the caseof masonry,penetration plaster,windowjunctions,falsewall installationsand roofjunctionsmustbe carefully detailed.DIN4108part7 containsimportant recornmenand usefuldesignand construction dations,and shows- see fig. 2.6.43- detailsof and jointsin overlaps,junctions,penetrations plane of imperviousness. the Requirements for thermal insulation

stanand measuring Thedesign,calculation dards providedin CEN/TC89 "Thermalperformanceof buildingsand buildingcomponents" formthe basisfor the NationalApplication Documentsof the seriesof standardsbelongand energy insulation ingto DIN410B"Thermal economyin buildings".Thetype and extentof is stilla matterfor the individual requirements countries.In orderto maintainminimumrequirethe measures, mentsand plan energy-saving followingpartsof DIN4108mustbe adheredto: parl2: for thermal Minimumrequirements insulation part 4: valuesrelatingto Characteristic thermalinsulationand protection againstmoisture of annualheatand oart 6: Calculation annualenergyuse Airtightnessof buildingcomponents vorr /. recommendations and connections; for planningand Perand examples formance for supp.2: Thermalbridges- examples planningand performance

. Draughtsimpairingthe comfortof occupants . Condensation damageresultingfromwater vaoourconvectionof the moistinternalair to cold externalzonesof enclosrngcomponents ' Loweredsoundinsulation the minimumrequireagainstexternalnoise DIN4108part2 specifies ' Energylossesthatforma considerable of components pad of mentsfor the thermalinsulation lt andthermalbridgesin the buildingenvelope. thetotalenergylossesof a building. alsocontainsadvicepertinentto thermalinsuof occuTheairtightness of buildingsas wellas individ- lationfor the designand construction the useof which ualresidential unitsor roomswithina finished piedroomsin buildings, requiresthey be heatedto commoninternal accordingto DINEN buildingis determined (> 19'C).Minimum thermalinstan- temperatures ISO9972 (blowerdoor).This international overpres- sulationis understoodto be a measurethat the useof mechanical dardspecifies guaranteesa hygienicinteriorclimate;with appliedto buildings. sureor underpressure a assuming adequateheatingand ventilation is generally definedby the Theairtightness usage,at everypointon the conventional remaining air changerateof the buildingor so part of the buildingat a pressuredifferenceof surfacesof the buildingenvelope lnternal formsoverthe whole that no condensation The airtightness can be 50 Pa (nro-value). area,nor in corners.Apartfromthat,the riskof assessedon the basisof the nuoair change Majorchangesin mouldgrowthis diminished. for the ratesgivenin table2.6.44.Thresholds the 2000editioncomparedto the 1981edition air changeratewerefirstlaiddownin DIN the doublingof the minimum involvepractically for buildings with 4108part7. The n.o-value per value for the thermalresistanceof external hour, for is limited to 3.0 naturalventilation the more wallsfromR > 0.55to R > 1.2m2KNtl, 1.0per withmechanical ventilation buildings detailedtreatmentof thermalbridges,measof the hour,ln additionto the reouirements standard,it is consideredadequate,takinginto uresfor avoidingthe growthof mouldand the thermal of minimum assessment when simplified accountpracticalbuildingtolerances, for heavyand lightweightcompoinsulation the measuredair flow rate,relatedto the volumeof air in the room,exceedsthethreshold nents.We nowonly distinguishbetweencomtotalmassof at givenin the standardby up to 0.5 per hourat a ponentswith a surface-related pressuredifferenceof 50 Pa. least100 kg/m3and componentswith a lower As mightbe mayexpected,masonrybuildings totalmasswithouttakingintoaccountthe posigenerallyhavea betterairtightness tion of layersof insulationand theireffecton than lightheatingand coolingprocesses.Thefact that However,evenin weighttypesof construction.

Thermalinsulation

lowerstoragemassis compensatedfor by betterthermalinsulationis solvedsimplyby applying enhancedrequirements with R > 1.75m2K/"N for components< 100 kg/m3, whichcorresponds to the formermaximum valuefor lightweight In the case components, frames,the valueappliesonlyto of structural theinfillpanels.Inthesecasesan averageof R > 1.0m'zKAN is to be maintained in addition forthe entirecomoonent.Fuftherdetailshave alreadybeendescribedin the sectionson thermal bridgesand airtightness.

' Primaryenergyrequirement: the amountof energyrequiredto coverthe finalenergy requirement, takingintoaccountthe additionalamountsof energyconsumedby upstreamprocesschainsbeyondthe system boundaryof the buildingduringthe production,conversion and distribution of thefuel used.

2.6.42 f emperaturelimitsto DIN 4108 part 2 for thermal bridge calculations Temperaturee Partof buildingor surroundings

'c

Basement Soil Unheatedbufferzone Unheated roof

10 5 10

hasbeen Up to now,the heatingrequirement but the new subjectto certainstipulations, standardis coupledto the heatingenergy requirement, i.e,the primaryenergyevaluation, 2.6.43 Examplesof sealingto DIN 4108 part 7 Energy-savings Act in orderto incorporate the efficiencyof the Puttingfiguresto the requirements for energy- plantandthe energycarrierused.Thismeans savingthermalperformanceis the objectof thatthe balanceframework,whichpreviously public-law statutesaimedat energy-saving endedat the radiator,now extendsbackto the construction, The stipulationof an annualener- powerstationor to the supplyof gas or oil. gy requirement in the Energy-savings Act is Act corOnekeyelementin the Energy-savings respondsto a oerformanceclassfor different for the stricterframeworkof requirements methods of energy-saving the aimof whichis definedin principal energy-saving construction, document No.6 "Energyeconomyand heat to cut consumptionby an averageof 3O7ofor retention". The EuropeanstandardDIN EN832 newbuildingworkandto bringthe previous servesfor itstechnicalimolementation. This thermalinsulation andtechnicalolantrequirestandardrefersto a seriesof furtherdesign mentsand upgradingrules,as appliedto the standards, suchas the calculationof the speexistingbuildingstock,up to the currenttechcificheatlosscoefficient,heattransferto the nologicallevel.As in theThermallnsulation soil,dynamicthermalparametersand the treat- Act,thisact coversbuildings withnormalinter(min.19'C);the definition mentof thermalbridges.The raw datafor the for naltemperatures designstandards includesproductfeatures, withlowerinternal temperatures 1 Airtightlayer buildings 4 Urdl rpil rg uorrsr r e.g.thethermalconductivity of insulation maremainsunchanged. 3 Compressedsealingstrip Adhesive terials and masonryconstructions. The logical Buildings withnormalinternal temperatures 4 lnternalplaster connection betweenthe variousdesign,promustcomplywithmaximum figuresfor the (seefig. ductandmeasuring standardsis illustrated in annualprimaryenergyrequirement Junctionbetweenroof and plasteredmasonrywall fig.2.6.45.Furthermore, nationalboundary 2.6.46),dependingon thetypeof building conditions, e.g.climatedata,solargains,inter- Al/e. The specification of the primaryenergyis nalheatsourcesand air changeratein DIN intendedto createa clearlinkto the political 4108part6, as wellas provisions for dealing objective of reducingcarbondioxideemissions withtotalheatlossesfroma heatingsystem and avoida distortionof the marketfor comandthe heatingrequirement for hotwatersup- petingenergysystems. On the otherhand,the pliesto DIN4701part 10,stillhaveto be spec- calculated finalenergyprovidesvaluableinforifiedin orderto finalizethe Europeanmethodof mationfor the useras a standardizedoredicanalysrs. tion of the consumption to be expectedand at Experience hasshownthatambiguous in an "energy desig- the sametimeformsa parameter pass"specificto the building. nationsand confusionoftenarisewhendesThe requirement cribingthermalinsulation and energyproperadditional ancillary requirement coveringthe ties.Therefore, the followingdefinitions is are maximumannualheatingrequirement 6 Sealingstrip laminated intended to provideclarity: intendedto ensurethatthe oreviousstandard with non-wovencloth ' Heatingrequirement: heatto be deliveredto of thermalinsulation to the buildingenvelopeis Junctionbetweenwindowframe and masonrywall the heatedspaceto maintainthe temperature maintained. overa periodof time. forthe imperviousness of exRequirements ' Heating energyrequirement: the calculated ternalwindowsand glazeddoorsremain amountof energythat mustbe fed intothe unchanged. Theimperviousness of the buildheatlngsystemof a buildingto be ableto ing envelopeis dealtwithmoreprecisely by providinginformation coverthe heatingrequirement. on a suitablemethodof 2.6.44 Au chanqeratesfor airtightnesstesl ' Heating leakagerates. energyconsumption: the amountof measurement and permissible Recommendedvalues heatingenergy(energycarrier)measured To guaranteeenergy-saving summerthermal Air change rate at 50 palh Aidightness Detached Apartment overa certainperiodwhich is requiredto havebeen insulation, the previousprovisions of building maintaina certaintemperaturein a zone. improvedandtightenedup in linewithtech'1.0-3.0 0.5-2.0 very airtight . Finalenergyrequirement: the amountof nicalprogress. 3.0-8.0 moderatelyairtight 2.0-4.0 energywhichis requiredto coverthe annual A limitto the coolingrequirement hasbeen 8.0-20.0 4.0-10.0 l e s sa i r t i g h t heatingenergyrequirement which,becauseof their andthe heating imposedon buildings Thresholdvalues requirement for the provisionof hotwater, typeof facade function,demanda particular Air changesper h Buildingwith determinedat the systemboundaryof the Theminimumener- naturalventilation and coolingin the summer. nso33 n s o< 1 , 5 gy requirements buildingunderconsideration. for startingup heatingboilers, mechanicalextraction 't75

Building science

distribution apparatusand hotwatersystems in the HeatingPlantsAct havebeen stipulated en bloc. incorporated essentially temperawithlowinternal As before,buildings turesonlyhaveto complywitha maximum heatingrequirement annualtransmission the air changerate becausefor thesebuildings quite heatsourcescanfluctuate and internal dependingon use. considerably the Changesto existingbuildingsnecessitated previousprovisions to be adjustedto the of requirements for the thermaltransmittance , individual components accordinglo tig.2.6.47 meaforthermalinsulation Tighterstipulations suresto be carriedout duringrefurbishment workwerecreatedso that corresponding improvements affecting energyrequirements among wouldfinda widerangeof applications the existingbuildingstock.Withina specified pipesof a heatperiod,the heatingdistribution ing systemin an existingbuildingmustbe insulated andthe boileritselfbroughtup to the standardof newbuildingwork.

2 . 6 . 4 5 B r e a k d o w n o f T C 3 9 s t a n d a r d i z a t i o n w o r k a n d l i n k s b e t v v e e n i n d isvtiadnudaal r d s Energy-savings Act P l a n n i n ga n d d e s i g ns t a n d a r d s Buildings

Thermalperformanceof buildings Calculationof heatingenergyrequiremenl

Specifictransmissionheat loss coefficient E N t S O1 3 3 7 0 Thermaltransmissionvia the soil DraftEN 13786 Dynamicthermalproperties of components 1lparts1and

Method of calculation

2 , 6 . 4 6 Stipulations for primaryenergyrequirement 200 Primaryenergy with requirement hot water heated by electric

180 6

E 160

Primaryenergy requrrement with hot water heatedby boiler

c

? 140

; c

o 12n

Primaryenergy requirement without hot water

c o

= 100 o o >80

Energy-savings Act (Heatingenergyrequirementl

o o C^^ oou o c o I

20 0

0

0,1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1.0

1.1

, 4 / 1 m -1 2.6.47 Enerov-savinos Act (EnEV): measures for existinq buildinq stock Component

Externalwalls (internalinsulation,renewingof infillwalls) Externalwalls Windows Floors,roofs, pitched roofs (steep) Floors,roofs,pitchedroofs (shallow) Roofsand wallsto unheatedinteriorsor soil (insulationon cold side) Roofsand wallsto unheatedinteriorsor soil (insulationon warm side)

176

U-value Wm2k EnEV 0,45 0.35 1,70 0.30 o.25 0,40 0.50

Thecalculation of the heatingand heating is carriedout by usingthe energyrequirements European standardDINEN832 in conjunction DIN Document Application withthe National 4108part6 and DIN 4701part1O.Themethod accordingto DINEN832 is of calculation energybalancebut basedon a stationary does.however.take intoaccountinternaland changesas wellas the temperature external and solarheatgains. dynamiceffectof internal is calTheannualheatingenergyrequirement culatedaccordingto fig.2.6.48by drawingup a balancesheetof the lossand gainvariables Apartfromthe heatingrequirement involved. the heatingenergy dependingon the building, alsoincludesthetechnicallosses requirement of the heatingsystem,the energyrequirements for hotwaterand possiblegainsfromregenerativesystems.The lossesof the systemcan be accordingto DIN4701 calculated accurately part10 by way of quantityfiguresfor heat and storage,generation transfer, distribution, primaryenergyconversion for eachindividual for the caseaccordingto the plansavailable figure technicalservicesor by usinga quantity e^ for the entiresystemrelatedto the primary ehergy.Two methodsare availablefor deterThesimpler miningthe heatingrequirement. periodbalancemethod,alsopossiblewithout the use of a computerand restrictedto resiusesthe equation dentialbuildings, Q n = Q r ,n p - n H p x Q g , F j e

where: for the heating Q^ the heatingrequirement season Q,,n, the heatinglossesduringthe heating season

Thermalinsulation

boiler,condensing system(low-temperature withverifiedimperviousness, ingtechnology), douoptimized night-time dropin temperature, to ble glazingand a highstandardof insulation roofand basementareas. Themoreaccuratemonthlybalancemethod of the influencing ln such casesthe thermaltransmittance takesintoaccountfurthervariables wallshouldnotexceedU = 0.40Wm2K. theheatingenergyrequirement and broadens external Twin-leafmasonrywith additionalthermalinsutheplanningoptions.Theannualheating wallswiththermalinsulation requirement Qnis obtainedby addingtogether lation,single-leaf provided compositesystemsor thermallyinsulatedcontheindividual monthlybalances, therehavebeen positivevaluesfor each structionswithventilatedouterleavesare all possiblewithoutany problems. month,usingthe equation segmentsof a All the mainenergyrequirement n _sn buildingarecoveredby an "energyrequirev L! ' - ! v ! ^/ ""'' oos mentpass"for the followingpurposes: and . To providethe userwith information aboutthe Qn,v=Qr,v-nMxQs,M to be expected. energyconsumption DIN4108part6 containsthe limitsfor the heat- . To improveclarityin the housingand property marketwith respectto the qualityof buildingdegreedays,the averageavailable solar radiationand the averagemonthlyexternal ingsin termsof energyaspects. ' To supportthe implementation of the Act by temperatures and intensityof solarradiation puttingthe userin the positionio checkthe An necessary for bothmethodsof calculation. to energy, featuresof hisbuildingrelevant analysis of thermalinsulation accordingto pubunusualaspects. lic-lawrequirements mustalsoapplythe condiand to investigate A simplesummaryshowsthatthe heating tionsdescribedin DIN4108oart6, of a buildingis determined Theadvantagesof the monthlybalance energyrequirement methodarethatthe influencesof lighteror by fourfactors: . Climate:locationof building,external temperheaviertypesof construction on the degreeof ature,incidentsolarradiation utilization of the heatgainsand the effectof the night-time shape,volume,planlayout,orientadrop in temperature, as well as solar . Building: gainsvia glazedsections, of externalcomponents, opaquecomponents tion,construciion type of construction andtranslucent thermalinsulation can all be . Heatingsystem:heatgeneration, regulation, takenintoaccount.The air changerateof = per hotwatersupply distribution, n 0.7 hourfor naturalventilation, and its air changerate, reduction to n = 0.6 per hourif an airtightness . Use:internaltemperature, usablewasteheat. testis carriedout an$ the conditionn.o < 3 per houris therebyfulfilled, hasa decisiveinfluenceon the heatlosses.A furtherreductionin Thermal comfort ventilation lossescan be achievedby using Thethermalcomfortin a heatedroomessenmechanical ventilation with heatrecovery. of tiallydependson the surfacetemperatures ln the oeriodbalancemethodthe influence of the roomand on the air thermalbridgesis determined by a globalsur- the surfacesenclosing withinthe room.The velocityand heatloss temperature chargeon the specifictransmission U of peoplein humidityof the air,the activities the roomand clothingalsoplaya role.The comfortrangesof the individualfactorsare H*r=AU*rxA influlinked.Theair and surfacetemperatures perceivedby an occuAUwe= 0.05Wm'?Kcan be usedfor conencethetemperature pantsuchthat- withincertainlimits- a lower structionscomoarablein thermaltermswith for by a DIN4108supplement 2. Themonthlybalance air temperaturecan be compensated highersurfacetemperature(seefig. 2.6.49). methodalsopermitsthermalbridgelossesto val- Thereis a connectionbetweenthe desired be calculatedusingthermaltransmittance which humidityof the air and itstemperature, ues(y-values). can also be presentedas a comfortrange(see Thedegreeof comfortperceived Inaddition,quickimplementation of DINEN832 fig.2.6.50). is madepossibleby meansof globalreduction by an occupantmustbe assesseddifferently physiBasedon essentially for eachindividual. methodsor correctionvaluesderivedfrom exchange, suchas radiation European requiring cal processes comprehensive standards as wellas generand evaporation, intensive mathematical analysis. Thissimplifi- conduction intera favourable experiences, cationhas an effecton temperaturecorrection allyapplicable nal climateprevailswhenthe followingfactors factorsfor areasin a heatedbasementin parare oresent: ticular. . The externalcomponents- with goodthermal Calculations carriedoutfor individual typesof - havean internalsurfacetemperainsulation masonrywalls buildings confirmthatsingle-leaf tureof about18"C. arestillpossiblewith a higherstandardof heatsolar)during Qn,gpthe heatinggains(internal, the heatingseason Tlnp the degreeof utilization.

. The differencebetweenthe air temperature of enclosing and the surfacetemperature componentsdoes not exceed2 K. . The relationship and betweenair temperature relativehumiditylies,and is appropriately and balanced,in the rangeof O = 1B-24"C
Thermal insulation in summer

cooling mechanical Withsuitableconstruction, in buildsystemsare generallyunnecessary offices or individual apartments ingscontaining withsimilaruses. and otherbuildings in summeressentially Thermalinsulation of dependson the totalenergytransmittance theircomtransparentexternalcomponents, and, in the caseof roofwinoassorientation Otherfactorsarethe dows,theirinclination. optionsin the rooms,the heatstorventilation internalcompoage capacity(particularly nents),and the heatconductionpropertiesof subjecttononcomponents opaqueexternal constantboundaryconditions.Effectivesunshadesfor transparentexternalcomponents by way can be integratedintothe construction of overhangingroofsor balconies,by external or internalblindsor by usingsolar-control glass.The purposeof limitingthe ingressof solarradiationin the summeris to guarantee i,e.to avoid comfortableinteriortemperatures, for exceedingcertainthresholdtemperatures morethan10%of the occupancytime.In order limitsin warmerclito keeowithintemperature provided), the maticregions(withsunshades havebeenlaid down: followingrequirements ' summerclimateregionA; cool summerregions25'C . summerclimateregionB; moderateregions26oC . summerclimateregionC; hotsummerregions27'C solar of the dimensionless Thefixedthreshold Srr* mustnot be exceededin heatpenetration an analysis.Thisvalueis calculatedfromthe of the glassg, the totalenergytransmittance proportionof windowareaf in an elevation, and the reductionfactorF" for sunshadesas well as the windowframecomponentFr: Sru"z S = f x g x F" (1 - FF)/0.7 The thresholdis calculatedfroma basicvalue summerclimateregionas Sofor the applicable well as correctionfactorsdependingon construction and useaccordingto table2.6.51: Sr"" 2 So + x, AS, valuesapplyfor the design Thefollowing valueS^: 177

Building science

2.6.48 EN 832 (thermalperformanceof buildings):calculationof heatingenergyrequirementQ (finalenergy)and primaryenergyrequirementQp for residentialbu;lding

Q Heatingenergyrequirement Q, Heat gain from surroundings (renewableenergy) Qn Heatingrequirement Q* Heatingrequirementfor hot water supplres Qr Lossesfrom heating systems Q p Primaryenergyrequirement - p Primaryenergy-related total system cost index

\ Transmission

*

?imi" Q = Qn+ Q,+ Q,

' o,

Q p = ( Q h+ Q w ) . e p

2,6,49 Relationshipbetweeninteriorair temperatureand surfacetemperaturewith respectto the comfortof occupants[ 15] 30 28 26 Surface 24 remperalure 22 20 18. t oa 1t -

."1 a 1oL

12

20 22 24 Interior airtemperature 'C

26

2,6,50 Relationshipbetweeninteriorair temperatureand relativehumiditywith respect to the comfortof occupants[ 16]

22

24

Interior airtemperatureu

26 ("c )

2.6.51 CorrectionvaluesAS for basic characteristicvalueS^for solarheat oenetration lnfluencingvariablesito be considered Lightweightconstruction: panitions,suspendedceilings timberstudding,lightvveight Extremelylightweight construction: primarilyinternalinsulation,large hall,few internalcomponents glassitwith g < 0.4 Solar-control Increasednight-timeventilation(night n > 1.5,h during 2nd half of night) Proportronof window area in facade > 65% Roomsfacing north(NW-N-NE) Inclinedwindows(00-60"lo the horizontal)

178',

As' - 0.03 - 0.10 + 0,04 + 0.03 - 0.04 + 0.10 - 0.06

summerclimateregionA summerclimateregionB summerclimateregionC

So= 0.tB So= 0.14 So= 0.t0

Accordingto DIN4108part2, onlythe basic valueSo= 0.18for coolsummerregionsis for thermal usedas the minimumrequirement of wininsulation in summer,lf the proportion is dows in a westto southto eastorientation for a northlessthan2Oo/o, or lessthan3Oo/o or less orientation, eastto northto north-west is than157ofor slopingwindows,an analysis nornecessary. methodaccordingto DIN lnlhe differentiated forthe so4108pad 6, the specifiedthreshold heatgains non-usable calledstandardized, (whichcan alsobe interpretedas ovenemperaturedegreehours)mustnot be exceeded. The methodof calculationmakesit possibleto take intoaccountvariousfactors,e.g. internal of facade,air change heatloads,orientation method The differentiated rateetc.,accurately. withhigh suitablefor buildings is particularly internalloadsor enhancedpassivesolarenergy use.Buildings withinterior coolingshould in sucha be initially designedand constructed for thermalinsulation way thatthe stipulations in summerarecomoliedwithandthe residua heatis removedby usingmechanicalsystems ( s e ef i g .2 . 6 . 3 6 ) .

moisturecontrol Climate-related

is reached.lf the air coolsfuri.e.saturation, ther,the watermustbe separatedout fromthe air, becausethe air at thattemperaturecan no Theeffectsof moisturecausedby building longerholdthat amountof waterin vapour rainand conwork,normallivingconditions, remaina problemin the construction form.Mistformsin a gaseousatmosphereor densation on solidsudaces.Thetemperaindustry. Therefore,measureshaveto be taken condensation ture at whichthis processbeginsis knownas to keepmoistureof any kind awayfromthe or simplydew or reduceit to a safeminimum.Inade- the dew pointtemperature, building measuresto avoidthe quatemoisturecontroldecreasesthe levelof ooint.Constructional fallingbelowthe dew pointon temperature thermalinsulationand can leadto laterdaminternal sudaceshavebeendealtwithin the ageto the masonrythroughcorrosion,frost, in coniunction insulation" Figure2.6.52 section"Thermal mouldgroMhand efflorescence. ls a diagramn loadson a build- withthermalbridges, of the moisture ing. Climate-relatedmoisture control

Fromoutsidewe havethe effectsof: . rain.snow.moistexternalair . moistsoil,seepagewater,a build-upof water,groundwater Frominsidewe havethe effectsof: ' moisture fromnew buildingwork . waterin kitchensand bathrooms ' dampness plants causedby the household, from andwashing,and moistureevaporating theoccupants . moisturecondensingon the internalsurfaces of components or withinthe components.

2.6.52 Moistureloadson externalcomponents

Drivingrain Surface water

Hygroscopic moisture

Porousbodiesabsorbmoisturein the formof Vapourditfusion air accord- Seepagewater l watervapourfromthe surrounding ingto theirphysicaland chemicalproperties. Dissolvedsalts Adsorptionmay causewatermoleculesto collecton the surfaceof a materialin one or more And layers,accordingto the relativehumidity. strucwitha capillary-like in porousmaterials ture,watercan alsoaccumulateon internal surfaces.lf the watervapourin thesecapillariescondenses, thewatermovesaccordingto This processis knownas the lawsof capillarity. Thesetwo mechanisms 2.6.53 Variables,symbolsand unitsused in moisture capillarycondensation. general physical'variables, headingof "sorption". The symbolsand unitsrele- comeunderthe vantto the assessment of moistureprotection The hygroscopicpropertiesof buildingmater- Water vapour partial Pressure p 1 which Relativehumidity ialsare describedby sorptionisotherms, @ aregivenin table2.6.53. kg/kg u Mass-relatedmoisture content on the moisturecontentin orovideinformation m2h Water vapour diffusion coefficient D eachcasedependingon the relativehumidity Water vapour diffusionflow rate kg/m'?h s (seefig.2.6.55). of the ambi- Watervapourdiffusionresistance z Thetemperature Humidity m'?hPa,rkg The hygroWatervapourdiffusionconduction entair hasonlya smallinfluence. Theair in the atmospherealwayscontains kg/mhPa 6 scopicwatercontentthat becomesestablished coefficient watervapourfromthe evaporatlon of water. Water vapour diffusion is important undernormalambientconditions Depending air can hold on thetemperature, resistanceindex !rl onlya certainamountof watervapour,and this for assessingmoistureratiosin a materialin kg/m2 ho 5 w Water absorption coefficient practice.Thehygroscopic moisture Water vapour diffusionequilibrium increases as the temperaturerises(seefig. sdm contentsof variousbuildingmaterialsare given equivalentair layerthickness 2.6.54). As moistair cools,the dew point(or Area-related (for climaticcondiin table2.6.23 reference value)is reached.The saturation saturation kg/m2 flw,r condensationmass contentof watervapourin the air corresponds tionsof 23"Cand 807orelativehumidity). Area-related kg/m2 flwv mass evaporataon Besidesthe finalvaluesfor sorptionmoisture vapourpressuredependingon to a saturation in the constant whichbecomeestablished temperature. Thisalso increasesas the temperaturerisesto the samedegreeas the behaviourof surface state,the non-constant sincethey act as layersis also interesting capacityto holdwatervapour. humidities. internal Inthe majorityof casesthe air containsslightly bufferzonesfor fluctuating 2.6,54 Watersaturationor dew pointgraph morewatervapourthanthe respectivesatura- Kunzel[62] has shownthat it is the properties of the outermostsurfacelayersthat are partictioncontentallows.The relativehumidityQ ularlyrelevantfor short{ermmoisturechanges, servesto designatethe watercontentof the air.Thisis the ratiobetweenthe actualamount and thatthe substanceof the wall beneath plasteror wallpaperno longerhasany influof watervapourpresentW and the saturation witha quantityW" or the ratiobetweenthe prevailing ence.On the otherhand,furnishings tr carpets, watervapourpartialpressurep and the satura- hightextilecontent,e.g, upholstery, tc curtainsetc.,havea highsorptioncapacity, 6 tionpressureps,givenby o flucmoisture whichmeansthatno significant c o ln rooms in living expected tuations should be 0=W/Vs=p/ps C and bedrooms,and the sorptionbehaviourof o o is unimportant. buildingmaterials Forsaturatedair O= 1.0or 100%.As moistair =s heatsuo in a roomwithoutthe additionor extraction of air,so the relativehumiditydrops becausethe possiblesaturationquantityrises for a constantquantityof watervapour.In the reversesituation- moistair cooling- the relativehumidityincreases untilthe valueof 100%,

Buildingscience

2.6,55 Rangesof sorptioncurves

Capillarity

-

b !

r(

C

o c o oo

1n

l

>c

0

Relativehumidity(%) B

c

Clay bricks,gypsum ght concrete,lightweight concrete,autoNormal-wei clavedaeratedconcrete,calciumsilicate Timber,organicfibrousmaterials

2,6.56 Capillarywaterabsorptionof variousbuilding materialsin relationto the square root of the time (afterKLinzel)

,/ F o

E,u b. €6 -r o

,,

t/

3

0

W = wxrf

4

t/ t/u*

o 6

3s

5 -'t-

1

2

3

45

1: Gypsum1390kg/m3 2: Solidclay bricks 1730 kg/m3 3: Autoclaved aerated concrete 640 kg/m3 4: Calciumsilicate1780kg/m3 5: Pumiceconcrete880 kg/m3

In water-filledporesand tube-likematerial structures in buildingmaterials, capillary tensileforcesoccur due to the surfacetensionof water,dependingon the concaveradiusof the meniscusand the wettabilityof the solidmaterial.Thecapillarysuctioncan haveeithera positiveor negativeeffecton the building,depending on the moistureloadand the associated moisturemovement.The absorptionof water and conveyance by capillaryactiondueto drivingrainor moistsoiimustbe avoided.On the otherhand,the capillarity of a buildingmaterial promotesthe transportof waterfromwithina buildingcomponent to the surface,whereit then hasthe chanceto evaporate.Thisacceleratesthe removalof moisturefromthe building process frommasonry.In the caseof condensationformingwithinthe masonrydue to watervapourdiffusion,the amountof condensationcan be reducedby capillaryactionand the chanceto dry out improved.A standardizedtestin DINEN ISO15148is suitablefor establishing the waterabsorptionof a capillarytype porousmaterial.In thistest a samplesurface is immersedin waterand the increasein massdeterminedas a functionof the absorotiontime.Thewaterabsorptionincreaseslinearlyin proportionto the squarerootof the immersion time(seefig.2.6.56). Thecurve correspondsto the waterabsorptioncoefficient specificto the material:

6 7 8 I 10 Time (h)

180

Z=1.5xl06xpxd the diffusionflow rateis indirectConsequently, ly proportional to the diffusionresistancegenand thethickness of the builderallyapplicable proping material. Thedimensionless material ertyp specifiesby how muchthe diffusion resistanceof a materialis greaterthanthe stationaryair.The ;r-valueof air is therefore1. As the thicknessis of courseimportantfor calculatingthe diffusionresistanceof a component or layerof a component,in practicewe usethe diffusion-equivalent air layerthickness so=pxd Thisunitis specifiedin m. In somecasesthis characterizes the diffusionpropertiesof a buildingmateriallayerbetterthanthe p-value on its own.Thisis particularly truefor thin layThe ersand vapourbarriers(seetable2.6.59). diffusion-equivalent air layerthicknesses of thin layershaverecentlybeendefinedin DIN4108 oart 3 as follows:

where: W = the quantityof waterabsorbedfor a unit - open diffusionlayerwith sd< 0.5 m surfaceareainkg/m2 - diffusion-resistant = the absorption t timein h layerwith = w the waterabsorptioncoefficientin 0.5 m < so< 1500m - closeddiffusionlayerwithso > 1500m. kg/m2h{5 Table2.6.58givesw-values for materials typicallyusedfor buildingwalls.

Water vapour diffusion

2.6.57 Walervapourtransportthroughan externalcomponent a temperaturegradient p Watervapourpartialpressuregradient

is easilyillusout occurrence of condensation tratedfor a single-layer component(seefig. 2.6.57).Thewatervapourdiffusionflow rateg in kg/m'zh througha componentin the constant stateis calculated usingthe equationbelow. To do this,we mustknowthe watervapourparp;and p" in Pa on bothsidesof tialpressures the componentas well as the watervapour diffusionresistanceZ of the component.At a referencetemperatureof 10"C,Z can be calculated from

in physicalterms,air is a mixtureof gasesin whichthe nitrogen,oxygenand watervapour molecules circulateindependently. Eachindividualgas exertsthe samepartialpressureit wouldexertat the sametemoeratureif the othergaseswere not present.Existingmoisture differencesin tvvoblocksof air are balancedby watervapourdiffusionin the directionof the potentialgradient.Thisdiffusion shouldnot be confusedwitha flowwhich occursas a resultof a totalpressuredifference.In diffusionprocesses,the sametotal pressureis generallypresenton bothsidesof a separatinglayer.The externalcomponentsof heatedinteriorsare subjectedto watervapour diffusionprocessesbecausetheyseparate blocksof air with differenttemperatures and moisturecontents.The diffusionorocesswith-

Watervapourdiffusionresistances for building materials and masonryarespecifiedin DIN 4'108oart 4 and DIN EN 12524.Twovaluesare givenin DIN4108part4 in orderto take accountof the scatterfor type of materialor type of masonry.In calculatingthe diffusion, the lessfavourablewatervapourdiffusion resistanceshouldalwaysbe usedfor the condensingperiod.Thismeansthatwhencondensationoccurswithina type of structure,the lowerp-values shouldbe usedfor calculating the quantityof condensation on the inner (warm)sideof the condensation.plane or conzone,and the higherp-values forthe densation outer(cold)side.However,the valuesusedfor should calculating the massof condensation be retainedfor calculatingthe evaporation options.Table2.6.60providesan overviewof for the watervapourdiffusionresistances masonryand plastergivenin DIN4108part4. In contrast,the EuropeanstandardDIN EN 12524distinguishes betweenwatervapourdiffusionresistancesdeterminedaccordinqto the

moisturecontrol Climate-related

dryand moistzonemethodof DIN EN ISO 12572.ln the firstcasethe materialis essentiallydry duringthetestbecausethe humidities on bothsidesof the sampleare approx.0% and50%,but in the secondcaseabout50% and95%,so thatfor hygroscopicmaterialsan appropriaiemoisturecontentbecomesestablishedand influences the p-valuethroughthe transport of the sorbedwater(seefig. 2.6.61). Conesponding figuresfor buildingmaterials canbe foundin table2.6.62.lt can be seen for the moistzonewiththe thatthe ;r-values greaterflowof sorbedwaterare lowerthan thosefor the dry zone.

2.6.58 Waterabsorptioncoefficientof buildingmaterials(afterKunael) Gross density Mate{bl

normal-weighl lightweightconcrete

solid verticallyperforated vertrcallyperforated e solid calciumsilicate solid calciumsiiicate pumiceconcrete pumiceconcrete autoclaved aerated concrete autoclaved aerated concrete autoclaved aerated ooncrete normal-weight concrete concrete normal-weiqht

Water absorption coefficient

2.9 8,3 11 1635 1760 1920

7' 7 5.5 3.2 2.9 1.9 4.0 4.2

alq

1085 535 600 630 2290 2410

1,8 1.1

Calculating the quantity of condensation within components

Thequantityof condensation accumulating withina component andthe chanceof drying outcan only be estimatedand not accurately concerncalculatedowingto the assumptions ingtheclimaticboundaryconditions and the widescatterof materialparameters. Evensubcarriedoutwithinthe sequentcalculations, scopeof assessingdamage,arefraughtwith uncertainties. Thewatervaoourdiffusionresistanceis the mostimportantmaterialproperty butcanvaryconsiderably in practicedueto utilization effects.In the caseof hygroscopic materials the watervaoourdiffusionis concealedby sorptionprocessesand flowsof adsorbatefilms. Severalmethods- with differentclaimsto the posaccuracy- are knownfor investigating siblesaturation of componentsby the formawhichresultsfromthe diftionof condensation, ferencebetweenthe amountof wateraccumulatingand the amountable to dry out.The Glasermethodis coveredby a standard.This is a simplegraphicmethodfor estimatingpossiblemoisturebleedingwithinthe cross-sectionof a wallandthe possibledrying-out basedon a constantstatefor the temperature zoneandthe vapourpartialpressuregradient. Withconstantclimaticconditionsfor the condensingperiodovertwo wintermonthsand the periodoverthreesummermonths, evaporating we alsospeakof the blockmethod.Figure presentation 2.6.63is a schematic of a simple plane diffusion diagramwitha condensation betweenlayers2 and 3, as wouldbe the case, for example,in a twin-leafmasonrywallwlth However, cavityinsulation. owingto the misunderstandings whichoftenoccur in practice,it mustbe emphasized thatthe DINmethodis an estimateof the accumulation of condensation andits possibledrying-out as wellas a checkprovedoverdecades- of the absolutesafety of a componentsubjectedto standardconditions.Theclimaticboundaryconditions and the methodof analysisare describedin detailin DIN4108part3. The basicrequirement is that theformationof condensation withincomponents,whichleadsto damageor impairment of

air layerthicknessto DIN EN 12524of thin layers 2.6.59 Watervapourdiffusion-equivalent water vapour Producvmaterial diffusion-equivalent air laYerthickness Dd

Polyethylene 0.15 mm Polyethylene 0.25 mm Polyestersheet0.2 mm PVC sheet Aluminium f o i l0 . 0 5m m Polyethylene sheet(stacked)0,15 mm Bitumenizedpaper 0.1 mm Aluminiumcompositefoil 0,4 mm Roofingfelt for walls Coatingmaterial High-glosslacquer

m 50 100 50 30 1500 8 2 10

o,2 0.1 3 2

of a stationary of a productis specifiedas the air layer Note:The watervapourdiffusion-equivalent layerof air with the samewatervapourdiffusionresistanceas the product.The thicknessof the productin the table is not normallymeasuredand can be relatedto thin productswith a watervapourdiffusionresistance.The table specifies nominalthicknessvaluesas an aid to identifyingthe product

2.6.60 Recommendedvaluesfor diffusionresistanceindexesto DIN 4108 paft 4; upper and lowerlimitsof material scatter Recommendedvaluefor water Material vapour diffusion resista!eelnqell0l) Plasters I 5/35 Plasteringmixesof lime,lime-cemenl and hydrauliclime 10 Plasteringmixesof lime-gypsum,gypsum,anhydriteand lime hydrite 15/20 Lightweightplasters 10 Gypsumplasters 5/20 Thermalinsulationplaster 5o/2oo svnthetic resin Dlaster Masonryof 50/1Qo solid engineeringbricks,verticallyper{oratedengineeringbricks high-strengthengineeringbricks 5/10 solid clay bricks,verticallyperforatedclay bricks lightweightverticallyperforatedclay bricks 5/10 calciumsilicate,grossdensity1.0-1,4 15/25 calciumsilicate,grossdensity1.6-2,2 70/100 granulatedslag aggregateunits 5/10 autoclavedaeratedconcrete 5/10 lightweightconcrete

181

Buildingscience

2.6.61 Diagram of direction of diffusion uponmeasuringthewatervapourpermeability in thedryand moistzones,andspecification of thewatercontentin thesamptes andsorbate watertransDoft fora hygroscopic material withthegivensorptioncurve(afterK0nzel)

the surrounding air is achieved. Moisturetransportin componentstakinginto effects accountsorption,diffusionand capillarity subjectedto non-constant climaticconditionsis reflectedinthe KieBlmethod[94].The asso. ciatedcomputerprogram'WUFI'[219]takes intoaccountthe conditionsof the temperature 5 0 % | 5 -0 % ^ . ( e , g . t h r o u g h c o r r o s i o n , m o u '| d g r o w t h ) ' Water accumulatingwithinthe component and relativehumidityof the internaland exterI 1 e3l periodmustbe ableto nal air as well as the rainloadand the radiation duringthe condensing I I I t I ] escapeto the surroundings lossaccordingto the inclination and orientation againduringthe / fi e3% uo:/ 3olo evaporatingperiod. of the component.Thisinformation can be obI (^' ) ,1 t I) I| " g __,_ &. lf | l . T h e a r e a - r e l a t e d q u a n t i t y o f c o n d e n s a t i o ntainedfrom measuredweatherdataor from shouldnot exceed1.0 kg/m,for roofand wall test referenceyears,Materialdatasuchas porosity,specificheatcapacity,thermalconconstructions. Sorption moisture Sorbatewater Sorption moisture ' lf condensation In sampte in sample transport occursat the contactfacesof ductivity,diffusionresistance,moisturestorage capillary, non-absorbent layers,the permisfunctionand fluidtransportcoefficientare all put intothe calculation. siblecondensation massmaybe reducedto The computerprogram progression 0.5 kg/m2;provisionscoveringtimbercomthen determinesthe chronological ponentsare givenin DIN68800part2. of the temoeratureand moisturezonewithin 'An increasein the mass-related moisture the component. contentu exceeding5% is not permittedfor timber(3%for timberderivatives); wood-wool 2.6.62 Watervapourdiffusionresistanceindicesfor the and multi-ply lightweight buildingboardsto Moisture behaviour of masonry dry and moistzonesto DIN EN 12524 Material Watervapourdiffuson DIN1101areexcludedfromthis. DIN4108paft 3 describescomponentsthat,in resistanceindex the lightof experience,can be regardedas p ln contrastto the DINmethod,Ihe Jenisch and absolutelysafewith respectto saturation, dry moist methodlakesintoaccountthe temoerature for whicha'mathematical analysisof condenPlasteringmix 20 10 Clay brick 16 10 relationships at the location of the building sationis not required.The conditionfor this is Calciumsilicate 20 15 Thismakesuseof the meanannualfigure adeouateminimumthermalinsulation accord[90]. Concretewith expanded and the frequencyof the dailyaveragefor the ingto DIN4108part2 and normalinterior climefAV AdflrAnrlcc 6 4 externalair temperaturein certainclimatic ates.Figure2.6.64providesan overviewof Concretewith lightweight aggregates 15 10 zonesin orderto establishwhetherthe massof externalwall constructions whichare absoluteAutoclaved aerated concrete 10 6 condensation occurringin a component ly safein termsof the formationof condensacan dry outagainduringoneyear,Thismethodis tioninternally. slightlymoreinvolved thanthe DINmethodbut suppliesa moreaccurateannualbalancefor The masonrywallsare made up as follows: the occurrence of condensation and the 2.6.63 Water vapour diffusionwith condensation . Single-leaf chanceof it dryingout. masonryto DIN1053part1 and occurringin one planeof the building The COND method moisture walls of autoclaved aeratedconcreteto enables a l72l component profilein multi-layer enclosingconstructions to DIN4223with internalolasterand the followingexternallayers: be calculated on the basisof the coupledheat, tzo - rendering watervapourand capillarywatertransport,and to DIN18550part1 D.- O ^|sw - in termsof - claddingsto DIN18515parts1 and 2 ui= hence forms a solid foundation for 7t moisture- a correctand differentiated attachedby mortaror bondingwitha joint proportionof at least5% approachto the physicsof the buildingstruc- ventilatedexternalwall claddingsto ture.Startingwith a simpleblockclimatefor winterand summer,similarto DIN4108part3, DIN18516part1 withandwithoutthermal the capillarity insulation and hygroscopicity of the build- externalinsulation ing materialaretakenintoaccountin addition to DIN1102or to the watervapourdiffusion,As the cold seaDIN 18550part3 or an approvedthermal son begins,the differencebetweenwater insulationcompositesystem Diffusiondiagramfor condensationcase . Twin-leafmasonryto DIN 1053part 1, also vapourquantitiesdiffusingintoand out of the material,initiallywithoutformationof condensa- with cavityinsulation Al subtion,is usedto createa hygroscopicloadwith- . Wallsof masonrywith internalinsulation l tzJ ject to the followinglimitations: in the component. Once the water vapour satu-p, p .SW I rationpressureis finallyreached,condensation - internalinsulation with a thermalresistance 4 doesformbut,at the sametime,capillaryrelief of the thermalinsulationlayerR < 1.0m2KAiV begins.The balanceof vapourand capillary as well as a valuefor the watervapourdiffuwaterflowsleadsto a reducedmoistureload sion-equivalent airiayerthicknessof the -O 'Ds w comparedto the purediffusionmethod.During thermalinsulationlayerwith internalplaster e the warm partof the yearthe.materialis or internal claddingsdi> 0.5 m 4 - internalinsulationof plasteror clad woodrelievedby watervapourand capillarywater transport- untilthe condensation has dried woollightweight buildingboardsto DIN1101 furtherdryingtakesplaceuntil out.Finally, with R < 0.5 m2KAlVwithout anyfudher Diffusiondiagramfor evaporationcase hygroscopicmoisturecontentequilibriumwith requirement for the so,-value

'u

't82

the function due to the increase in moisture contained in building and insulating materials, should be avoided. This is generally the case when the following conditions are satisfied: . Building materialsthat come into contact with condensation should not suffer any damage

moisturecontrol Climate-related

. Externalbasementwallsof single-leafmasonry to DIN '1053part 1 or concreteto DIN 1045 withexternalthermalinsulation. Theseprovisionsin the standardsare based on manyyearsof experience and,as a rule,lie deviatesfrom on the safeside. lf a construction thisdoes thedetailsgivenin the catalogues, will notnecessarily meanthatthe construction fail,A numberof selectedinvestigations of externalwallsshowthe serviceability of facade claddings withIimitedventilation, the useof variouscombinations of materialsfor twin-leaf masonrywith cavityinsulationand the absence of problems- in termsof moistureprotectionwithinternalinsulation. Thewall protectedby an externalcladding,with or withoutadditional thermalinsulation, is a provenformof wall conThetransportof moisturefromthe struction. wallto the outsideis achievedas shownin fig. 2.6.65by ventilation to the rearof the cladding in conjunction withthe formationof condensationon the innerfaceof the cladding,which which thendrainsaway.Themechanism appliesdependson the degreeof ventilation. Tile-like, small-format elementsalso benefit froma considerablemoistureexchangeby wayof the perviousness of the cladding[131]. Therefore, if a claddingis notventilated according to DIN18516,thisdoesnotrepreon senta defect,providedthe condensation therearface of the claddingcan drainaway and doesnot leadto damageto the loadbearingconstruction [130]. ln a full-fillcavity wall,thermalinsulationmaterialswithanywatervapourpermeability can be withall relevantbuildingmaterials combined forthe innerleafand an outerleafof clay or calciumsilicatefacingbricksl5l. Whencalculatingthe diffusionaccordingto DIN4108part3, the amountof condensation according to figure2.6.66liesbelowthe maximumoermissiblecondensation massof 1000g/m'z, evenfor the mostunfavourable opento diffusion caseof thermalinsulation (e.9.mineral wool,looseinsulation) and a thin innerleaf.Onlyfor an outerleafof engineering bricksmustwateroccurringwithinthe compoperiodbe ableto nentduringthe condensing escapeagainto the surroundings duringthe period(m*:m* < 1) notfulfilled evaporating on paper- for insulatingmaterialsopento diffusion(seefig.2.6.67). Takinglntoaccount laboratory testson samplesof wall in a Munich-based thermalinsulation researchcentre,furtherpracticalinvestigations [53] and the factthatthe condensation that occursis onlya fractionof the amountof drivingrainthat peneVatesan outerleaf,a full{ill cavitywall can be regardedas absolutelysafe,evenwhen using engineering bricks,with respectto the formawithinthewall. tionof condensation Practical studiesof the formationof condensationwithincomoonentswith internalinsulation havebeencarriedout on commonformsof

2,6.64 biternal masonrywallsfor which a mathematicalanalysisof condensationis not necessary Single-leafwalls:monolithic,with ventilatedcladding,with thermalinsulation comDositesvstem

Single-leafwall with internalinsulation R < 1 . 0m 2k

l. . Ir - w

rtl

1 5 62; 0 . 5 m

Twin{eafwalls:with cavity,with partialJillcavity,with full-fillcavity

-

tl E E E E lt

E E E E

Basementwall with externalinsulalion

-

tI

r

E E

r

fl

masonrywith differenttypesof internalinsulation in laboratorytestsunderthe climaticconditionsaccordingto DIN4108part3 [a]. Masonry wallsmadefromno{ineslightweight calciumsilicateand claybrickswith concrete, materials such insulating diffusion-permeable as mineralfibres,eventhosewithoutvapour barrier,are absolutelysafewith respectto saturationin winter.Thethermalinsulation period. remainsdry duringthe condensing However,the increasein the watercontentof the masonryexceedsthe limitof 1.0 kglm'z accordingto DIN4108part3. The necessary periodis duringthe evaporating drying-out achieved.Theoreticalstudieswith a constant internalclimateand practicalexternalclimate [95] confirmthis assumptionfor certaintypes of masonry.As in the laboratorytests,they producehighermoisture in the fluctuations masonrycomparedwiththe use of denser insulationmaterialsor vapourbarriers.Butt jointsnearthe coveringon the innerfacein conjunctionwith rigid expandedfoamsor mineralfibre boards,with vapourbarriersinterrupted at the buttjoints,haveno measurableeffect on the watercontentof the masonry.Investigationscarriedout on existingstructuresconfirm Insulatingmathe laboratorymeasurements, e.g.calciumsiliterialswithactivecapillaries, cate,haverecentlybeenfavouredfor the interwithfacadesworth nal insulation of buildings preserving of just40 mm can [73].A thickness

valuesoften halvethe thermaltransmittance A diffusion in old buildings. encountered to resistanceU = 5 allowsthe construction Possible condenremainopento diffusion. and is dispersed sationbehindthe insulation relievedby the highcapillaryactionso that layersare unnecessary. diffusion-resistant Apartfromthat,the pH valueof calciumsilicate makesit resistantto mouldgrowthand the is a helpin regulating its hygroscopicity loadpeaksin internal climate,i.e.moisture the interiorare buffered.

183

Building science

2.6.65 Schematicpresentationof moistureloss in externalwallswith claddings.With idealventilation (O"= 4),the wall moistureis carriedaway with the air (right).With lessthan idealor no ventilation (Oa< O,),some moisturediffusingout of the wall can condenseand drain away (left)[7]

,$i

Water vapour convection

Wallsand roofsmustbe airtightto preventthe through-flow and convection humidiof internal ty, whichcan leadto the formationof condensation.Specialattentionshouldbe paidto the airtightness of junctionswith othercomponents and servicepenetrations. Transverse flowsin ventilation layerswithina constructionbetween roomsheatedto differenttemperatures should alsobe avoided.Facingmasonryand timber frames,as wellas masonryto DIN1053part1, are not airtightwithoutfurthertreatment. These typesof wallsmustbe givena coatof plaster to DIN18550part2 on onesideor madeairtight by othersuitablemeasures.Plastersto DlN 18550 DarL2 or 1B55Bare classedas airtightlayers.

Protection against driving rain

Drivingrainloadson wallsarecausedby the simultaneous effectof rainand wind blowing againstthe facade.The rainwatercan be absorbedby the wall by way of the capillary actionof the surfaceor entervia cracks,gaps 2.6.66 Condensationmass mwr in relationto diffusionor defectivesealsas a resultof the oressure equivalentair layerthicknessof innerleaf build-up.lt mustbe ensuredthatthewater Thermalinsulationlayer:mineralfibre boards Outer leaf:clay facing bricks enteringthe construction can escapeagainto the outsideair, Providinga wallwith proteciion againstdrivingrainin orderto limitthe absorption of waterby capillaryactionand to guaranm 800 tee evaporation opportunities can be achieved in throughconstructional measures(e.9.external g/m' 600 cladding,twin-leaf masonry) or throughrender.\--:___=-=ing or coatings.The measuresto be taken dependon the intensity of the drivingrainload, l 400 whichis determined by the directionof the I windandthe levelof precipitation as wellas the localsituation and typeof building.Accord200 ingly,threeloadinggroupsare definedin DIN 4108part3 in orderto assessthe behaviourof 0.5 1.0 1 . 5m external wallssubjectedto drivingrain.A rainDiffusion-equivalent air layerthickness fall map of Germanyprovidesgeneralinformation aboutprecipitation levels.However,this is onlythe startingpointfor assessing drivingrain (u=5) 0.1 0.2 0.3m becausethe localcircumstances, altitudeand Thickness of innerleaf formof the building(roofoverhang, heightof building)must alsobe takenintoaccount(see fig.2.6.68). Therefore, the loadinggroupsfor Germanyare definedwith associatedexplanations:

,l

Loadinggroup I - low drivingrain load As a rule,thisloadinggroupappliesto regions withannualprecipitation levels< 600mm but alsoto locationswell protectedfromthe wind in regionswithhigherlevelsof precipitation. Loadlnggroup ll - moderatedrivingrain load As a rule,thisloadinggroupappliesto regions with annualorecipitation levelsof 600-800mm as well as to locationswell protectedfromthe windin regionswithhigherlevelsof precipitationandto tallbulldings or buildings in exposed positions in regionswherethe localrainand

184

wind conditionswouldotherwisecausethemto to the lowdrivingrainloadinggroup. be allocated Loadinggroup lll - high drivingrain load As a rule,thisloadinggroupappliesto regions levels> 800 mm or to with annualprecipitation windyregions,eventhosewith lowerlevelsof precipitation (e.9.coastalareas,hillyand of theAlps), mountainous regions,thefoothills or buildingsin as wellas to tallbuildings exposedpositionsin regionswherethe local rainandwindconditions wouldotherwise causethemto be allocatedto the moderate drivingrainloadinggroup. Externalwallswith rainprotectionprovidedby usingthe rendering or coatingsareassessed waterabsorptioncoefficient w for water absorptionduringrai,nfall and the diffusion. equivalentair layerthicknesssd of the layer providingrain protectionfor the lossof water duringdry periods[106].In orderto limitthe short{ermincreasein moistureduringrainfall, the waterabsorotioncoefficientshouldnot exceeda certainvalue,evenwhendrying-out is guaranteedin the longterm.The lowerthe diffusion-equivalent air layerthicknesssdof the surfacelayer,the morequicklythe component loseswater- whichenteredduringdrivingrain - in the dry period.So such a surfacelayer or water-repellent shouldbe water-resistant with respectto rainprotection,but at the same as possiblefor timeremainas permeable watervaoourto allowthe moisturewhichhas penetratedto escapequickly.The requirementsfor rainprotectionprovidedby rendering and coatingsare definedin DIN4108part3 (seetable2.6.69). The rainorotectionis confinedto the outerleaf in the caseof twin-leafwallswith an air space or masonrywith a ventilatedcladding.Aittightare the tasksof the nessand thermalinsulation jnnerleaf.ln a full-fill cavitywall,the cavity to insulation shouldnotimpairthe resistance drivingrain,and moisture shouldnotbe ableto Thecavireachthe innerleafviathe insulation. ty insulationmustbe coveredby a standard, will haveto be veriotherwiseits serviceability regufied in accordance withbuildingauthority lations.Loosematerialsand mineralfibre boardsmustpossesshydrophobicproperties to repelthe water.An overlappingstepped jointis adequatefor plasticfoamsin orderto guaranteethatthe waterdrainsto the baseof materialsare the wall. lf loosecavityinsulation employed,suitablemeasuresmustbe takenat the openingsat the baseof the externalleafin orderto preventmaterialfromescaping.As with a cavitywall,a damp proofcoursemust be providedat the baseand aboveall openingstogetherwithweep holesto allowdriving rainwhich has penetratedthe outerleafto drainaway. Whenusingthermalinsulationcompositesyscouldendanger tems,cracksin the rendering

moisturecontrol Climate-related

thedrivingrainprotection and impairthethermalinsulation mainlyprovidedby the external thermalinsulationlayer,The effectsof cracks in renderinghavebeen investigated on externalwallssubjectedto naturalweatherconditionsat the open-airtest centreof the FraunhoferInstitute for BuildingPhysics[14].After threeyear,sof exposureto the weather,it can generally be saidthatfor rendering on rigid foam expandedpolystyrene and polyurethane sheetsas wellas hydrophobic mineralfibre boards,crackswith a widthof approx.0.2 mm do notimpairthefunctionof the rendering as rainprotectionto any significantextent,providedthe substratedoes not conductthrough As a capillaryactionor is water-resistant. simpleplanningaid,DIN4108part3 gives of standard examplesof the classification typesof wall accordingto the threeloading groups(see2.6.70).However, thisdoesnot ruleoutthe useof othertypesof construction provedby yearsof practicalexperience.

2.6.67 Drying-outoppodunitiesin relationto the diffuair layerthicknessof insulation sion-equivalent materialwhen using outerleavesof clay facing bricksand engineeringbricks

2.6.68 Allocationof drivingrain groupsaccordingto positionand form of building

m*/m*

t12 I

l"

0.8

Engineering

Xi"to'

;r;l

E3E

0.6

____-,,"i<

ll

:l:

Efii tt*ttt

o.4 0.2

--{1----

I bricks

air layerthickness Diffusion.equivalent u x s of insulationmaterial

for rain protectionto renderingand coatingsaccordingto DIN 4108 part 3 2.6.69 Requirements Diffusion-equivalent air layerthickness coefficient requirement sd

- Product wxsd kg/m6os

<w<2.0

2,6.70 Examplesof the allocationof standardwall types and loadinggroupsaccordingto DIN 4108 part 3 Loadinggroup lll Loadinggroup ll Loadinggroup I high drivingrain load moderatedrivingrain load low drivingrain load renderingto Water-repellent rendering Water-resistant Renderingto DIN 18550pt 1 DIN 18550pts 1-4 or syntheticresin to DIN 18550pt 1 on withoutspecialrequirements plasterto DIN 18550on for drivingrain protection . Externalwalls of masonry, wall panels,concreteor similar . Wood-woollightweight boards (with reinforcedjoints) . Externalwalls of masonry,wall panels,concreteor similar . Multi-plylightweightboards 'Wood-wool and multi-plylightweightboards (reinforcedover entire surface) a c c o r d i n gt o D I N 1 1 0 2 t o D I N 1 1 0 1 ,i n s t a l l e d t o D I N1 1 0 1 , installed a c c o r d i n gt o D I N 1 1 0 2 Twin-leal leaf pt 1, 375mm thick to DIN 1053 pt 1 with partialto t o D I N 1 0 5 3o t 1 . 3 1 0 m m t h i c k (withinternalplaster) or full-fillcavity (wjthinternalplasteo

wallswithtilesor pan" Externat

t o D I N 1 8 5 1 5p t 1 a p p l i e d in water-repellentmortar outer laverof concreteto DIN 1045 and DIN 1045 pt 1 (draft)as Externalwallswith dense microstructure D I N 4 2 1 9p t s 1 & t o D I N 1 8 5 1 6o t s 1 , 3 & 4 with ventilated e)dernal 18550 pt 3 or an approved with externalinsulationby meansof a thermalinsulationplastersystemto thermalinsulation tion 8.2 of DIN 68800 pt 2 Externalwalls in timberwith weather Note:Drainediointsbetween aoolied in thick-or thin-bedmortar

185

Building science

Sound insulation

2.6.71 Soundlevelsof varioussources

is becomingmoreand more Soundinsulation This the buildingindustry. important throughout primarily relating to the concernsquestions healthandwell-being of people.Soundinsuimportant in housingbelationis particularly causethis is whereoeoplerelaxand restand needto be shieldedfromthe everydaynoises is an And soundinsulation of theirneighbours. partof the buildingsystemif indispensable schools,hospitalsand officesareto be used properly. in buildingsbegins Soundinsulation noiseat the designstage.Forinstance, roomslikebedroomsand living sensitive roomsshouldbe placedwithinthe planlayout so thattheyare unlikelyto be affectedby unacceptable externalnoise;a usefulexpedient is to groupthoseroomswithsimilarfuncsound tionstogether.Besidescarefulplanning, insulation measures can onlybe successful when greatcare is exercisedduringconstruccan lead tion,Evenminorflawsin workmanship to, for example,acousticbridgesfor structurenullifythe bornenoise,whichthenpractically Puttingright measures. entiresoundinsulation is in manycases suchproblemssubsequently expensive. impossible or at bestextremely

Sound level dB(A) Jet engine (at 25 m)

140

-

130

Jet aircrafttakingoff ( a t 1 0 0m )

120 D^^ I vv

^r^' '^ v,uuv

110

-

100 <-Heavy goods traffic

Pneumaticdrill

90

-

,..-

Average traffic

-

Office

<

Livingroom

<

Forest

6U 70 Conversation ;

OU

50 Library

40

-

30 Bedroom

>

Terms and definitions

20

is the protection against Soundinsulation soundwhichis conveyedin variousways (seefig,2.6.72):

10 0

L l m i to f a u d i b i l i t y

. Airbornesoundis soundwhichpropagates in air (a gaseousmedium).Uponstrikinga solid part body (buildingcomponent), of the airbornesoundis reflectedand part is absorbedor attenuated. ' Structure-borne soundis soundwhichpropa: gatesin solidmaterials. In buildings theseare noisescausedby buildingservices frequently whicharethenconveyedvia and machinery the construction. . lmpactsoundis a specialformof structurebornesoundcausedby peoplewalking acrossthe floor.

2.6.72 Airborneand structure-borne sound Excitationof airbornesound

Excitationof structure-borne sound

*)),),

2.6.73 Frequencyranges Infrasound

A u d i b l er a n g e

Rrrilrlinn

aanr re+inc

Speech -----?

186

Ultrasound

vibration of an elastic Soundis the mechanical mediumwhosefrequencylieswithinthe audible rangeof the humanear (between16 and f is definedas the num20 000 Hz).Frequency per second.As thefrequency ber of vibrations increases the pitchrises.A doublingof thefrequencycorresponds to oneoctave.In building witha we are generally concerned acoustics rangeof fiveoctaves- from100to 3150Hz (seefig.2.6.73). The periodicsoundvibration pressurein air or flugenerates an alternating ids knownas soundpressurep. The sound pressureis superimposed on the staticpresmediumand can surepresentin the respective be measuredby usinga microphone. The soundpressurelevelL describessound

Soundinsulation

events in buildingacoustics. As the humanear isina position to perceivea rangeequalto 1 x 106, thesoundpressurelevel(oftenabbreviatedto SPL)is describedusinga logarithmic Thisis the base 10 logarithm scale, of the ratio ofthesquareof the respectivesoundpressure p to thesquareof the referencesoundpressurepo:

thewallson all sidesas wellas doorframes insulatand servicepenetrations, by a resilient Inglayer.

2.6.74 Exampleof formationof averagevaluewith the aid of the evaluationcurve cdB o c .E

Requirements

550

F

Minimumreouirements for soundinsulation l c o havebeenlaiddownin a numberof construc!lo c-" tionlawdocuments. DIN4109specifies l o L = 10 log,o(p'/po') requirements for airborneand impactsound individual functional unitsin insulation befureen Theunitof soundoressure for protection or soundleveldifbuildingsand requirements ference isthe decibel(dB).Thesoundlevelis againstexternalnoise.lt shouldbe notedhere Displaced specified usingtheA-scaledB(A);thisis based thatthe requirements applyonlyto the sound g components performance ontheA-weighting network, whichapproxiof separatin matesto a scaleof volumecomoarableto that befuueen differentresidential or officepremisfor ofthesensitivity of the humanear.A soundthat es;thereare no minimumrequirements increases by 10 dB is perceived to be twiceas soundinsulation withinresidential or office premises. loud,Thesoundlevelextendsfromthe limitof 1 to DIN4109(examSupplement audibility has 0 dB(A)to the painthreshold . A num- plesof detailsand methodsof calculation) 0 berof typicalsoundlevelsare givenin fig. beenimplemented by the buildingauthorities. 400 800 1600 3200 100 204 rz f FrequencY 2.6.71. Sosoundinsulation meansreducing the Supplement 2 to DIN4109 (recommendations 1) LSM = alrbornesound nsulationmargin soundlevelsof soundsourcesto an acceptfor enhancedsoundinsulation and suggesablelevelwhentheycannotbe diminished. withinoremises) has tionsfor soundinsulation Thesoundreduction indexR describes notbeenimplemented the by the buildingauthoriinsulating effectof components againstairties,and necessitates a specialagreement bornesound.Thisis calculated fromthe sound betweendeveloper Bearingin and architect. 2.6.75 Transmission paths for airborne sound qualityawareness leveldifferencebefuueen of hryorooms(source mindthe increasing throughthe separatingwall (path1), Besidestransmlssion andreceiving rooms)takingintoaccountthe users,the designershouldcheckwhetherthe the alrbornesound is alsotransmittedvia paths2,3 and 4 absorption surfaceA of the receivingroomand enhancedsoundinsulation measures of supplement2 can be implemented thetestsurfaceof the comoonentS: takinginto accounttechnicaland economicaspects.A guideto the contentsof DIN4109and the supR=!-Lr+10tog,o(S/A) plementsis givenin fig.2.6.76.Workon Europeanstandardization fhe airbornesound insulationrndexR* is a is beingcarriedout by singlevalueforthe simpleidentification thetechnicalcommittee CEN/TC126"Acoustic of building components. As showninfig.2.6.74, properties of buildingproductsand of builda curveB,theshapeof whichtakesinto ings". account thesensitivity conof the humanear,above TheEuropean standardis essentially thelineof measured frequencies M, is disof testingmethcernedwiththe harmonization placeddownwards Flankingtransmission in steosof 1 dB untilthe and in situ),the evaluation of ods (laboratory average undershoot U of the displacedgrade testresultsandthe drawing-up of methodsof curvebelowthe measuredcurveis max.2 dB. calculation for determining the acousticperJorThesoundreduction indexof the displaced manceof buildingsbasedon the properties of gradecurveat 500 Hz is takenas the single theircomponents. Thestandardsbeingproidentifying value. ducedfor thisby CENwillhavea directinfluInpractice the airbornesoundinsulation index enceon the provisions of DIN4109.TheGerfor sound 2.6.76 Requirementsand recommendations isspecified takingintoaccountthe sound manbuildingacoustics constandardization insulation (seefig. transmission viaflankingcomponents Designation lmplementedContenl overceptwillhaveto undergoa fundamental by building 2.6.75). Flanking transmission is thatpartof the haul.The DINstudygroupsresponsible are authorities airbornesoundtransmission betweentwo adworking standardization concept currently on a Protectionof occupied Yes D I N4 1 0 9 jacentroomswhichdoes nottake placedirect- thattakesthe harmonized codesintoaccount. roomsagainst . noisesfrom roomsnot lyviatheseparating 1 willneedto component but insteadvia BothDIN4109and suoolement belongingto the same pathsthroughadjoinin g components. be revised. auxiliary premises lmpactsoundis structure-borne involves soundgener- Theworkto be carriedout essentiallv . noisesfrom building atedby walkingor similarexcitation of floorsor thefollowing areas: servicesand operations on the same premises stairs,and is transmittedto the roomsbelow . externalnoiseand the partlydirectlyas airbornesoundor viaflanking ' A revision the curof DIN4109whileretaining noiseof commercialor components as structure-borne rentlevelof reouirements. soundwaves, lmpactsoundinsuiation is usuallyimprovedby . Theproduction of a buildingcomponent Examplesof construction Supplement1 Yes detailsand methodsof t o D I N4 1 0 9 a two-layerarrangement in the formof the floor catalogue. calculation finishbeingsupportedby a "floating" methodof construc- . The integration of the harmonized Advice on designand S u p p t e m e nZt t l o tionon thestructural floor. in the Germanbuildingacoustics t o D I N4 1 0 9 calculation constructionand A floating screedis a supporting layerwhichis concept,including the drawing-up of instrucfor recommendations enhancedsound insulation separated fromthe structuralfloor,and from tions.

187

Buildingscience

from other 2.6.77 Aibo"ne sound insulationfor walls and doors to preventsoundtransmission residentialor workingareas _.__ Recommendations Fequirements Componenl for enhanced t o D I N4 1 0 9 r ) sound insulation cr rnnlomon+

ronrl P'

r^^d

?zl

R'

dB dB 1. Multistoreybuildingswith apartmentsand work rooms Partywalls betlveen apartmentsand walls betureenseparate >55 worKpremrses 53 >55 523j Staircasewallsand wallsadjacentto communalcorridors 55 Wallsadjacentto driveways,entrancesto commongaragesetc. Wallsto gamesor similarcommunityrooms 55 Doors ' which leadfrom communalcorridorsor stairsto corridorsand >37 27 hallwaysin apartmentsand residentialhomesor from work rooms; . which lead from communalcorridorsor stairsdirectly 37 rooms corridorsand 2. Semidetachedor terracedhouses >67 Partv walls 57 3. Hotelsetc. Walls betvveen . oeorooms 47 . corridorsand bedrooms 47 Doors 'between corridorsand bedrooms ac >37 4 . H o s p i t a l sc,l i n i c s >52 Wallsbetween ' patients'rooms ' corridorsand patients'rooms . examinationor consultationrooms ' corridorsand examinationor consultationrooms . patientsroomsand work or nursingrooms Wallsbetuveen ' operatingtheatresor treatmentrooms 42 ' corridorsand operatingtheatresor treatmentrooms Walls between 37 ' intensivecare rooms ' corridorsand intensivecare rooms Doors between ' examinationor consultationrooms 37 . corridorsand examinationor consultationrooms ' corridorsand patients'rooms ac >37 . operatingtheatresor treatmentrooms atm,gn!r,og!lt! : golllqgrs and operating t 5, Schoolsand similarplacesof education Wallsbetween . classroomsor similarrooms ' corridorsand classroomsor similarrooms Wallsbetween 52 ' stairsand classroomsor similarrooms Wallsbetween 55 ' "particularlynoisy"rooms (e,9,sportshalls,musicrooms, work rooms)and classroomsor similarrooms Doors befureen 32 ' corridorsand classroomsor similarrooms 1) Extractfromtable 3 of DIN 4109 2) Extractfrom table 2 of supplement2 to DIN 4109 3) The followingappliesto wallswith doors:R'*(wall)= R*(doo| + 15 dB; wall widths< 300 mm are not considered here.

and workwillinvolvemasonry The necessary reinforcedconcrete,steeland otherframes, doors elements(windows, timberconstruction, etc.)and buildingservices. 3 tt o D I N4 1 0 9h a s I n G e r m a n ys,u p p l e m e n period.This beenpreparedfor thetransition the airborne containsa methodfor converting in the indexR* determined soundinsulation intoa withoutflankingtransmission laboratory valueR'w,whichis stillrequiredat presentfor the Germansystem.Thereverseprocedure, R'* to R*, is alsoincludedin the i.e.converting su00lement. for soundinsulation The levelof requirements in buildingsis notaffectedby the European Theestablishment of requirements standard, the provinceof national remainsexclusively bodiesand can thereforebe adjustedto the traditions and developrespective national Accordingindustry, mentsrnthe construction in thisrespect ly, DIN4109is notthreatened level. at European by developments

Sound insulationagainst internal noise

of DIN4109 f able2.6.77liststhe requirements 2 to of supplement and the recommendations DIN4109for a numberof selectedwallsfor protecting occupiedroomsagainstsound or working fromotherresidential transmission premises. for occupantsis Soundinsulation and withinthe sameresidential alsoimportant whenroomsservedifferent workingpremises purposes, workingand restingperior different requireods apply,or enhancedinsulation 2 to DIN Supplement mentsaredesirable, for standard 4109 containsrecommendations Table2.6.79 and enhancedsoundinsulation. providesan overview of the corresponding and officebuildings. for residential suggestions valuesforthe permissible DIN4109stipulates roomsin orderto soundlevelin noise-sensitive provideprotectionagainstnoise frombuilding servicesand operations.In orderto maintain are laiddownfor thesevalues,requirements of the airborneand imoactsoundinsulation noisy" between"particularly components to noise(seetable roomsandthosesensitive to be living 2.6.80). The latterareunderstood rooms,bedrooms,hospitalwards,classrooms noisy"roomsare: and offices,"Particularly . Roomswith"pafticularly noisy"buildingplant or servicesif the maximumsoundpressure levelof the airbornesoundin theseroomsfrequentlyexceeds75 dB(A). . Roomshousingcontainers for rubbishchutes and accesscorridorsto such roomsfromthe outside. ' Roomsfor craftor commercialactivities, if the maximum includingsalesactivities, soundpressurelevelofthe airbornesoundin exceeds75 dB(A). theseroomsfrequently . Restaurants. caf6s.snackbarsandthe like.

188

Soundinsulation

. B o w l i n ga l l e y s ' Kitchens for hotelsetc.,hospitals, clinics, restaurants; not includedhereare small kitchens,preparationroomsand communal kitchens. 'Theatres ' S p o r t sh a l l s . Musicand workrooms.

2.6.78 The airbornesound insulationindex R'- accordingto the mass law can cvv

-:

Concrete, masonry, gypsum, glass and similar building materials

cc ovv E

.g

Sher ST

E A^A

"'rt

to

mm thick i

= C

Inmanycasesit is necessary to provideadditionalstructure-borne insulation to machines, apparatusand pipesoppositesoffitsand walls ofthe building.No figurescan be specified herebecauseit dependson the magnitude of thestructure-borne soundgeneratedby the machineor apparatus,which is very differentin eachcase.Suppldment 2 to DIN4109providesgeneraldesignadvice.Thereis no requirement with respectto the airbornesound insulation indexfor the soundinsulation of wallsbuiltto concealbuildingservicesand plantif the area-related massof the wall is at least220 kg/m2- suchwallscomplywiththe permissible soundlevelfor noisesgenerated by waterpipes(including wastewaterpipes). Wallswith an area-related mass< 220 kg/m2 mustbe verifiedby a suitabilitytestto prove thattheyare adequate.Excessivenoisetransmissionin suchsituationscan be effectively reducedby attachinga non-rigid facingof mineralfibreboardand plasterboard on the side of the noise-sensitive room,Modernsystems forsuchwalls,witha facingor claddingthe full heightof the room,providevery good sound insulation.

Sound insulation against external noise

Various noiselevelranges,classified accordingto the actualor expected"representative externalnoiselevel",formthe basisof the provisions for the requiredairbornesoundinsulationof externalcomponentsto protectagainst externalnoise.Differentrequirements have beenlaiddownfor the bedroomsin hosoitals andclinics.occuoiedroomsin residential accommodation, hotelbedroomsand classroomsas wellas offices(seetable2.6.81 ). As the enclosing external components usually consisiof severaldifferentsurfaceswith differproperties, entsoundinsulation the requirementsapplyto the resultingsoundreduction indexR'*,,""calculated fromthe individual soundreduction indexesof the different surfaces. Therequiredsoundreductionindiceshaveto be increased or decreaseddependingon the ratioofthe totalexternalsurfaceof a roomto the planareaof the room.Forinstance,for a standardceilingheightof 2.5m, the requirementsgivenin table2.6.81arealreadyacceptablefor a roomdepthof 3 m and reductionsof up to -3 dB maybe exploitedfor greaterroom deoths. Therequirements for the resultingsoundreductionindexfor roomsin residential buildinos

;c3 0 f

o

@

a20-c

nr)er,timbel 0 e n \'atrv3 S

c

3

4 5 6

I 10

20

30 4050 70 100

200 300

500700

Area-relatedmass m' (kglm2)

t o D I N4 1 0 9

for sound insulationwithinresidentialor Suggestionsfor standardsound insulation reqd R'* dB Residentialbuildinq Wallswithoutdoors between"noisy" and "quiet"roomswith differentuses, e.g. betweenlivingroom and child's bedroom. Officebuildinqs Walls between rooms for normal office activities Walls between corridors and rooms for normal office activities Walls to rooms for intensivemental activitiesor for handlingconfidentialmatters, e.g. betweendirector'sofficeand anteroom Walls betvveencorridors and rooms for intensivemental activitiesor for confidentialmatters Doors in walls between rooms for normal office activitiesor in walls betweencorridorsand such rooms Doorsrn wallsto roomsfor intensivementalactivities or for handlingconfidentialmattersor in walls between corridorsand such rooms

enhancedsound insulation reqd R'* dB >47

37

2.6.80 Requirements for airbornesound insulationof walls and floorsbetween"particularlynoisy"+oomsand those to be insulated Airbornesound insulation Type of room index R'* reqd dB

with "particularlynoisy"

75- 80 57

or servrces Roomsfor craftor commercialactivities, salesactivities Kitchensfor hotelsetc., hospitals,clinics,restaurants, snack bars etc. Kitchensas above but also in ooerationafter 10 o.m. Restaurantsetc. not occuoiedafter 10 p.rh, Restaurants etc. - max.sound level LAF< 85 dB(A)- also occupiedafter 10 p.m

57

Restaurants etc. - max.sound level85 dB(A)< LAF< 95 dB(A) e.q. with electroacoustic Note:LAF= time-relatedsound level,which is measuredwith the frequencyevaluationA and the time evaluation F (= fast) as a functionof the time.

189

Buildingscience

of the flankingcomponentscan be assumedto be approx.300 kg/m3. generally Besidesthe fact that soundinsulation dependson mass,the internalattenuation (materialattenuation) of the materialusedis also importantto a certainextent.Thisattenuation is understoodto be the abilityof the materialto convertpartof the vibrationenergyinto heatand henceremovesomeofthe energy carriedout by fromthe vibration.lnvestigations Institutefor BuildingPhysics the Fraunhofer haveshownthatthe airbornesoundinsulation indexcan be set2 dB higherthanksto this effectfor plasteredwallsof materialattenuation autoclavedaeratedconcreteand lightweight aggregates of pumiceor concretecontaining < 800 kg/m3 expandedclaywithgrossdensities mass< 250 kg/mz. and an area-related University Acousticstudiesat Braunschweig haveestablishedthis 2 dB bonusfor plastered wallsof calciumsilicatewithgrossdensities < B0Okg/m3as well. J. Lang11071 showedlongagothatclaybrick wallswith comoarablemassesbut different oerforations exhibiteddifferencesin theirairindexof up to 10 dB bornesoundinsulation (seefig.2.6.83).Goselediscovered oneexplanationfor this in the effectof thicknessresowere deviations nances[62].Themeasured of the webswithattributedto the arrangement in the masonryunits.In onecasethewebs passthroughthe unitin a straightlineand serveto stiffenthe unit;in anothertheyare offset with respectto eachotherand worklikea set of springsin series.Morerecentstudies of walls haverevealedthatthe soundinsulation madefrom perforatedunitsdependsnotonly in the units of perforations on the arrangement but alsoon numerousotherfactors,suchas the type of mortarbed,thicknessof plasterand Single-leafwalls Thesoundinsulation homo- formatof the unit[176].Figure2.6.84shows of thick,single-leaf, geneouswallsdependsin thefirstinstanceon the differencebetweenthe measuredand calindicesfor wallsof culatedsoundreduction theirarea-related mass.The relationship perforatedunitswith differentarea-related index betweenthe airbornesoundinsulation R'* andthe area-related massis shownin fig. massesand differentproportionsof perfora' tions.The effectsof the variousinfluencing 2.6.78.Theorerequisite for the correlation aresumand the variables on the soundinsulation betweenthe airbornesoundinsulation marisedin table2.6.85, area-related massof a single-leaf wall is a closedmicrostructure and sealedconstruction. Positiveeffectsare broughtaboutby: . hardermortar lf thisrequirement is notfulfilled, thenthewall . thickercoatsof plaster mustbe sealedon at leastonesideby a completecoveringof firmlyadheringplasteror cor- . shortermasonryunits . coarselystructuredperforations withthick responding againstdirect coatingto insulate 2.6.82 webs, soundtransmission Table shows [62], the difference in the airbornesoundinsulation The problemsassociatedwith perforated indicesfor wallswith and withoutplaster.The curvein tig.2.6.78doesnotapplyto lightweight masonryunitsappearedin clay,calciumsili< 85 kg/m2and, accordingto DIN cate and concreteunits,and - accordingto components currentfindings- are not restrictedto a certain 4109,with an area-related mass> 630 kg/ms of buildingmaterial. can onlybe usedto describethe behaviour joint f able2.6.87orovidesan overviewof the chartwin-leaf wallswithcontinuous separating indicesfor airbornesoundinsulation becausein thisrangethe achievable sound acteristic and lightweight insulation is limitedby theflankingcompomasonrywith normal-weight indicesare mortarand plasteredbothsides.Thesevalues nents.Thegivensoundreduction '100kg/m3for a gross mass mustbe reducedby achievedonly if the averagearea-related

witha standardceilingheightof 2.5m, room depthsof at least4.5 m, and 10-60%window Noise Critical R'*,ru.reqd for external area,aredeemedto be fulfilledwhenthe indilevel external component vidual soundreductionindicesgivenin tables (in dB) range noise to the proportion of level BedOccupied Officesl) in DIN4109 according dB(A) rooms rooms windowarea- aremaintainedfor the wall and | <55 35 30 wtndow. ll 56-60 35 30 30 Thesoundreduction indicesof ventilation 6 5 ill 61 40 35 30 ductsand rollerblindboxesandthe associatlv 66-70 45 40 35 v 71-75 45 40 50 ed referenceareashouldbe takeninto ,) vl 76-80 50 45 accountwhencalculating the resulting sound 2) 2) vll > 80 50 ventilareduction index.Facilities for temporary r)Thereare no stipulationsfor the externalcomponentsof tion(e.9.openinglightsandflaps)areevaluatroomsin which,owingto the natureof the activitiescarried out in those rooms,externalnoisewhich enterssuch thosefor oermanent ed in the closedcondition. roomsmakesonly a minorcontributionto the internal (e.9.sound-attenuated ventilation ventilation noiselevel. openings)in the operating condition. 2)The reouirementsin these casesare to be established The representative externalnoiselevelis deteraccordingto the local circumstances. minedfor the variousnoisesourcesusing 2.6.82 Aiborne sound insulationindexof partywalls appropriatemethodsof measurement and withoutplaster,afterGosele evaluation. DIN4.109containsa trafficnoise R'_ tdBl nomogram in whichthe averagelevelcan be without with readoff dependingon thevolumeof trafficand plaster 240 mm vertically perforated the distanceof the buildingfromthe centreof clay bricks 50 53 the road.Specialanalysesfor trafficsituations 250 mm in-situconcrete 11 53 in whichthe nomogram cannotbe usedas well 240 mm hollowblocksof n' rmi^a ^^n^rdf6 as for railand waterbornetrafficare covered 16 49 200 mm storey-heightaerated by DIN18005part2. concrelepanets 45 47 Forair traffic,i.e.airports,the "Lawgoverning protectionagainstaircraftnoise"laysdown 2.6.83 Differentsound insulationof verticallyperforated noiseprotection zones.The provisionsof this clay brick wallswith approximatelyequal arealaw,or morerigorousnational regulations, related mass but different oerforations.after applywithintheseprotectedzones. J. Lang The representative externalnoiselevelfor comUnit cross-section Web crossmercialand industrialooerationsmakesuse of section (schematic) the dailyimmissions valuegivenin the developmentplanfor the respectiveareacategory Act. accordingto Germany's NoiseAbatement 2.6.81 Noiselevelrangesand sound reductionindex R'",r""to be maintained

WffiNA A: m'= 435kglm2, R*= 59 dB (continuouswebs from outside to inside) B: m' = 42okglm2, R*= 49 dB (webs offset with respect to each other)

rou X c) c .5 c60

.9 b l

o_^

OCU

o c

X

l

840

r

30

100

500

1000 2000 Hz Frequency f

190

Soundinsulation

density> 1OO0 kg/moand 50 kg/m3for a gross 2.6.84 Differencebetweenmeasuredand calculated 2,6.85 Influenceof masonryunit geometryand type ol (to DIN 4109 supplement1) airbornesound constructionon the sound insulationof wallsof < 1000kg/m3for wallsof lightweight density or oerforatedunits.afterScholl insulationindicesin relationto proportionof perautoclaved aeratedconcreteoanels.as well as forationsfor variouswallsof oerforatedmasonrv forgaugedbrickworkusingthin-bedmortar. units,afterScholl possibility Another of improving the sound AR.u" I n f l u e n c i nvga r i a b l e c0" insulation of internal walls- alsosubsequently I gementof perforations 1 0 - 1 5d B Arran ; - isto combinethe solidwallskinwitha nonapprox.5 dB Type of mortar cc0 o approx.5 dB "noisy" Thicknessof bed joints rigidcladdingon the sideof the separ- o C 5-10dB Thicknessof plaster atingwall,We distinguish betweentwo groups o o-r 5dB Unitformat = depending on the connection to the rigidwall The figuresgiven here representthe maximumchange in o (seefig,2.6.88). group Claddingsof A are that occurredupon changingthe sound insulationARmax respectiveinfluencesfor a constantwall mass in the fixedto the heavywall via a supportingframemeasurementdata available. work,whilethoseof groupB arefree-standing or bondedto the substrate viaa resilient con010203040506070 nection usingmineralfibreboards.Table Proportionof perforations(7o) 2.6.86 specifies airbornesoundinsulation indices forsolidwallswitha claddingon one side.lf,forexample, for thermalinsulation reasons,insulating battswith a high dynamicstiffnessareattached to a single-leaf rigidwall either fullybondedoverthewholesurfaceor justat discretepoints,thiscan degradethe soundinsulation if the insulatinq battsare 2 . 6 . 8 6 A i r b o r n e s o u n d i n s u l a t i o n i n d e x R ' w o f s i n g l e - l e a f r i g i d w a l l s w i t h a n o n + i g i d c l acdhdai rnagc; t e r i s t i c v a l u e s coveredby plaster. accordinsto QIN:||Sgjlpplpmg[ 1

Twin-leafparty walls Party walls of two heavy, rigid leaves with a

jointbringabouta concontinuous separating siderable reduction in the soundtransmission for example,adjoining between, apartments, Thesoundreductionindexof a twin-leafparty jointis determined wallwithcontinuous from thearea-related massof bothleaves,including coatsof plaster, similarly to single-leaf compo(without nents, Thedirectsoundtransmission flanking transmission) wallof solid of a twin-leaf leaves is 12 dB higherthancouldbe expected fora single-leaf solidwallwiththe samemass. Thejointextendswithoutinterruption fromtop offoundation to roofcovering(seefig.2.6.90). A jointpassingthroughthe foundation leadsto bettersoundinsulationin the basementbut as thisis a problemin termsof sealingthe building,thisarrangement remainsan exception. The12 dB bonusmayonlybe takeninto account whenthefollowinq conditions are with: complied 'The area-related massof eachleafmustbe at least150kg/m2and the distancebetween the leavesat least30 mm. . Witha separating joint> 50 mm,the arearelatedmassof each leafmay be reducedto 100kg/m'z, 'The jointmustbe filledcompletely withtightly jointedresilient boards,e,g.mineralfibre impactsoundinsulation boards. . Suchfibreboardsare notreouiredwhenthe area-related massof each leafis > 200 kg/m'?. Thejointbetweenthe leavesshouldnot be madetoothinas thiscan veryquicklyleadto acoustic bridges.On the otherhand,the optimumleafspacingsin termsof soundinsulation arehigherthanthe minimumvaluesgivenin

Area-related Airbornesound insulationindex R'wr) with cladding withcladding mass of without groupB groupA s o l i dw a l l cladding dB dB kct/m2 dB 49 48 100 37 50 49 200 45 54 53 300 47 56 55 400 52 58 57 500 55 1)Appliesto flankingcomponentswith an averagearea-relaledmass m'L.mean of 300 kglm'?The valuesare reducedby 1 dB for a "riqid"connectionbetweencladdinqand wall.

2.6.87 Airbornesound insulationindex R'* of walls plasteredboth sides in relationto the bulk densityclassand wall thickness Airbornesound Wall Gross Wall Airbornesound Gross insulationindexr)2) thickness insulationindexr)21 density density thickness R ' w( d B ) mm class mm R ' w( d B ) class Lightvveight Normal Lightweight Normal mortar mortar mortar mortar 45 175 1.0 40 39 0.5 175 48 240 43 42 240 cl 300 45 44 300 ^ x 365 553 47 365 3) 47 175 1,2 175 41 40 0.6 50 240 240 44 52 300 4C 46 300 365 48 365 ----i7s 175 48 43 42 0.7 52 240 240 45 300 300 56 365 49 365 50 LO 175 43 03 175 44 53 240 46 240 46 55 300 48 300 49 57 365 cl 50 365 ct 175 44 o.g r 7s 45 54 240 48 47 240 57 300 49 300 50 59 365 52 51 365 '?)A total of 40 kg/m2has been taken into account for the coats of plaster. 3)Thesegross densitiesare not generallycqlbrned with lightweig

191

Building science

2.6.88 Soundperformanceof favourablecladdinosto DIN 4109 supplement1 Groupl) Wall construction B o (no connection ,/,/,/./,/,/,/,/,/,/,/,/ ).'i or resillent Connectlon ffiW _ I 6 to wall) *> 500 nl o N '+

>5oo

^ o

Description i,thickness>25mm. 'v rvilrvvervr I plastered, gap between wall and timber studding > 20 mm, free-standingin frontof heavywall, constructionto DIN 1102 vrduuil

C l a d d i n go f p l a s t e r b o a rtdo D I N 1 8 1 8 0 t, h i c k n e s sl 2 . 5 o r 1 5 m m , constructionto DIN 1818.1(currentlyin draftform),or of chipboardto D lN 68763, thickness10-16mm, gap betweenwall and timber studding> 20 mm, free-standing'?) in frontof heavywall,with cavityfilled3)betweentimber studding,

x ,--;- I ? o /. nt

Claddingof wood-woollighhveightboardsto DIN 1101,thickness> 50 mm, plasteredfree-standingwith 30-50mm gap in frontof heavywall,constructionto DIN 1102,a 20 mm gap is sufficientwhen fillingthe cavityaccordingto footnote3

A'TIV\NVV\N\7\7 O

o nl

C l a d d i n go f p l a s t e r b o a rtdo D I N 1 8 1 8 0 t, h i c k n e s s1 2 . 5o r 1 5 m m , and fibre insulationboardsa), constructionto DIN 18181 (currentlyin draftform),discreteor linearfixingto heavywall.

O

v \ T (withconnection to wall)

O

(o ^1 1

-

Claddingof wood-woollighhr/eight boardsto DIN 1101, thickness> 25 mm, plastered,timber studdingfixed to heavywall, c o n s t r u c t i otno D I N 1 1 0 2 .

> 500 (o

"l.r t

C l a d d i n go f p l a s t e r b o a rtdo D I N 1 8 1 8 0 t, h i c k n e s s1 2 . 5o r 1 5 m m , constructionto DIN 18181(currentlyin draftform), or of chipboardto DIN 68763,thickness10-16mm, with cavityfilling3), timber studdingfixed to heavywall2).

adding claddingsof group B, and by at least10 dB for claddingsof group A. 2)In theseexamplesthe timber studdingmay be replacedby sheetsteelC wall sectionsto DIN 18182pt 1. 3tFibreinsulationmaterialsto DIN 18165pt 1 nominalthicknessbetween20 and 60 mm, Iinearf low resistanceE > 5 kNs/ma. , 4)Fibreinsulationmaterialsto DIN 18165Dt L aDolicationtvoe WV-s.nominalthickness> 40 mm. s'>5 l\,4N/m3.

2,6,89 Examplesof twin-leafwalls- two leavesemployingnormal-weight mortarwith continuousseparatingjoint betweenbuildings- in relationto gross densityclasses t o D I N4 1 0 9s u o D l e m e n1t Airbornesound Grossdensityclass of unit and min. wall thicknessof leavesfor twin-leafmasonry insulationindex 1 5 m m p l a s t e rP l , P l l Facingbrickwork 10 mm plasterP lV or P lll both sides both sides both sides (lime-gypsum (dB) o d e r P l l l ( l i m e l, i m e or gypsum plaster) cementor cementplaster) 2 x 10 kg/m' (2x25kg/m2) Min. thicknessof Unit gross l\.4in. thicknessoi Unit gross Unrtgross Min. thicknessof leaveswithoutplaster density leaveswithoutplaster density leaveswithoutplaster density mm class mm mm class class 57 0.6 2x175 2 x240 o.72t 0.6r) 2x240 2 x 150 0.9 2x175 2x175 0.94) 0,82) 2x115 1 2x150 1,03) 1 .24) 2x150 1 /5\ 1.4 2x115 2x115 62 0.6 2x240 2x24O 0,56) 0.66) 2 x24O 2x175 0.9 175 + 24O 0.87) 0,87) 2x175 2 x 150 0.9 2x175 1.07) 0,97) 2 x 150 1 A 2x115 1.4 2x115 1,2 2x115 67 1 2 x24O 2x240 1.0u) 2 x24O 0.9e) 1.2 1 7 5+ 2 4 0 175 + 240 1.2 1.2 175 + 240 1.4 2+175 2x175 1.4 1.4 2x175 1 1 5+ 1 7 5 1.8 t.o 1 1 5+ 1 7 5 1.8 1 1 5+ 1 7 5 2x115 2.2 2x115 2x115 2 2.2 l OOkg/m'? '?)The grossdensityclass may be 0.3 lesswhen spacing betweenleavesis > 50 mm and weightof each individualleaf is > 100 kg/m', 3)The grossdensityclass may be 0.4 lesswhen spacing betweenleavesis > 50 mm and weightof each individualleaf is > 100 kg/m'?. atThe grossdensityclass may be 0.5 lesswhen spacing beween leavesis > 50 mm and weightof each individualleaf is > 100 kg/m'?, s)The grossdensityclass may be 0.6 lesswhen spacing betweenleavesis > 50 mm and weightof each individualleaf is > 100 kg/m'?. 6)For leavesof gas concreteunitsor panelsto DIN 4165 or 4166, as well as lightweightconcreteunitswith expandedclay aggregateto DIN 18151or 18152,the grossdensity classmay be 0.1 lesswhen spacing betu/eenleavesis > 50 mm and weightof each individualleaf is > 100 kg/m'?. 7 )F o r l e a v e s ogf a s c o n c r e t e u n i t s o r p a n e l s t o D l N 4 l 6 5 o r 4 l 6 6 , a s w a se l il g h t w e i g h t c o n c r e t e u n i t s w i t h e x p a n d e d c l a y a g g r e g a t e t o D o l Nr l S l 35 2l , t h e g r o s s d e n s i t y class may be 0.2 lesswhen spacing betweenleavesis > 50 mm and weightof each individualleaf is > 100 kg/m'?. e)The grossdensityclass may be 0,2 lessfor leavesof gas concreteunitsor panelsto DIN 4165 or 4166,as well as lightweightconcreteunitswith expandedclay aggregateto D I N1 8 1 5 1o r . 1 8 1 5 2 .

192

Soundinsulation

thestandard, A twin-leaf solidpartywallcomplieswiththeminimumrequirements of DIN (R'*= 57 dB)whenthe leavesareeach 4.109 115mmthick.the unitgrossdensityclassis 1.4anda totalof 20 kg/m2of plasterhas been To meetthe recommendations of aoplied. withat least67 dB, enhanced soundinsulation to thethickness of eachleafmustbe increased 175mmforthesameunitgrossdensityclass. Table2.6.89specifies airbornesoundinsulationindices for variouswallconstructions to DIN4109supplement 1: these according havebeencalculated on the basisof the mass dependency of R'* andthe 12 dB addition.

Flankingcomponents

Theairborne betweenrooms soundinsulation notonlyof the dependson the construction wallbutalsoof theflankingcomseparating ponents betweenseparatandthe connection Thesound ingwallandflankingcomponents. reduction indicesfor separating components g i v e ni ns u p p l e m e n 1 t o D I N4 1 0 9a p p l yt o providedthefollowing flanking components conditions arefulfilled: . Theaveragearea-related massR'r.r""n is approx. oftherigidflankingcomponents 300kg/m'?. .A rigidconnection to the flankingcomponentsis guaranteed whenthe area-related massoftheseparating components exceeds 150kg/m'z. . Theflanking from are continuous components oneroomto the next. .Thejointsbetweenseparating and flanking aresealed. components lf theaveragearea-related massof theflanking components deviatesfromapprox.300 kg/m2, thesoecified soundreductionindexof the mustbe corrected(see separating component table2,6,94). Theinfluence of the correction the valueKr,,is relatively small.In contrast, walland connection betweenthe separating thesolidflankingcomponents hasa consider) .h i si s t h ec a s e a b l ei n f l u e n c(es e ef i g .2 . 6 . 9 1 T whena lightweight thermalinsulation external wallpassesa heavyseparating wallbetween to apartments withoutbeingfirmlyconnected it.Measurements carriedout by the Fraunhofer Institute for BuildingPhysicsrevealeda degrading of the soundreductionindexof up i.e.buttto 10dB in the caseof non-bonded, jointed, wallswhosejointsubsequently cracked andwas sealedwitha permanently elastic compound. A fixedconnection betweentheflanking,solid wallor floor, andthe separating components provided is thisis of a heavyconstruction, Theexamplein fig.2.6.91shows desirable. twotypesof junctionbetweena separatingwall betweenapartmentsand an externalwall:with slotandwith buttjoint.The buti jointbetvreen masonry wallsis equivalent to toothingand

and rigidity slotsin termsof buildingacoustics in the senseof DIN4109, of the connection providedthe buttjointbetweenthewallsis fully filledwithmortar.Thisappliesto masonryin whichalljointsarefilledwithmortaras wellas to masonrywithoutmortarto the perpends.The inclusion of stainless steelanchorsprovides additional security, flanking Anothertypicalcaseof increased occurswhenan external soundtransmission or wallis providedwitha rigid-clad(plaster plasterboard) layerof insulation of rigid expandedfoamor wood-woollightweight boardson the insidein orderto improvether(seefig.2,6.93)[5].Theincrease malinsulation in flankingtransmission broughtaboutby the resonance effectis on averageabout10 dB. for separatThismeansthatthe requirements apartmentsare ing wallsand floorsbefuveen no longerfulfilled.

2.6,90 Jointsbetweenbuildingswith or withoutjoint in foundationand iointat roof level

Groundfloor

Basementfloor

External walls

madeup of wallswith Facadesare generally airborne windowsand doors.Theresulting indexmaybe calculated soundinsulation accordingto DIN4109 takingintoaccountthe comtotalareaandthe areasof the individual ponentsandtheirairbornesoundinsulation indicesor - moresimply- designedas shown in the examplein figure2.6.95usingtablesof indices values.Theairbornesoundinsulation of the windowsare obtainedfromthe test Recommended certificates of manufacturers. valuesfor commontypesof windowswithini n s u p p l e m e n1t s u l a t i n g l a z i n ga r ei n c l u d e d t o D I N4 1 0 9 . indexof an Theairbornesoundinsulation walldependson itsconstrucexternalmasonry Forsingle-leaf external tion (seefig,2.6.92). that thethermalinsulation wallsit is initially governswhichwallmaterial of lowgrossdensiof 300-365mm Wallthicknesses ty is required. kg/m3generally of 500-BO0 and grossdensities orovidesoundreductionindicesof between45 and 51 dB dependingon the massof the externalcomponent. lf a renderedthermalinsulation layeris attachedto the outside,then- as has beenknownfor sometime- coatsof plasteron lightweight boardsdegradethe wood-wool of a wall[61]. Laterstudies thermalinsulation materihaveconflrmed thistrendfor insulation partials of high dynamicstiffness(polystyrene materials withlow cle foam),whileinsulation (mineral wool)bringaboutimprovestiffness in others mentsin somecasesbut a worsening dependingon theweightof plasterandthe Investigations material of the solidwall11661. haverecentlybeen thermalinsulation carriedouton I4 different sybtemson a wallof calciumsilicate composite in the perforated units[147].lmprovements insulation soundindexof up to 4 dB were withlow materials established for insulation (mineral fibreboardswith dynamicstiffness

2.6.91 Flankingtransmissionvia flankingcomponent; junctionbetweenpartywall and externalwall using slot or butt joint

-T

LOng-rerm reliability

Tensionresistant connectton Flatanchor 300x 22x 0.75mm

V4A steel 23651

Tensionresistant connection Flatanchor 300x 22x 0.75mm

V4A steel 2 f f i [

365

.1

Buildingscience

2,6,92 Examplesof airbornesound insulationindex R'* for variousexternalwall constructions Single-leafexternalwall 45-51dB

Single-leafwall with thermal insulationcompositesystem 47_51dB

300 - 365 I--

175

t-_|

f

tl

I Single-leafwall with ventilatedcurtainwall 57 dB 175

Twin-leafmasonrywith and withoutthermalinsulation 55-66dB

t tt

rl

f':]----J

II J-t L------l

Pf-_-_l LJ

".]---_--]

2.6.93 Exampleof externalwall claddingdetrimentalto sound performance(rigidthermalinsulationboardson inner face),afterGosele c. dB

Externaiwall 240 mm masonry,clad internally -\ with 12.5 mm plasterboardon 30 mm r i g i de x p a n d e d foam boards.

without cladding

o !

.g c^^

o tiu

with claddjng R',* = 47 dB

F o

=

c o 6

3

l o

a

(d C

o

. 5 dB if the area-related massof adjoining internalwallsdoesnot exceed5O7oof the innerleafof the external wall. . B dB if the area-related massof adjoining internal wallsexceeds50%of the innerleafof the external wall.

U

2.6.94 CorrectionvaluesKL,1to DIN 4109 for the airbornesound insulationindex R'*.*for rigid walls at flanking componentsof averagearea-relatedmass m'r,."un Type of separatingcomponent K, , in dB for averagearea-relatedmass m'r,,"un in kg/m2 400 S i n g l e - l e,arfi g i dw a l l s and floors S i n g l e - l e arfi,g i dw a l l s w i t hn o n - r i g i dc l a d d i n g s

194

+2

horizontal fibresor elasticized rigidexpanded polystyrene witha high boards)and rendering mass.Non-elasticized rigid area-related boardsresultedin a expandedpolystyrene worsening of -1 to -3 dB, mineralwoolwithverticalfibres(laminated boards)-5 dB. lnstallation by way of profiledrailspresentsthe of 2 dB, chanceto achievean improvement an evenwitha thincoatof plaster.Basically, externalwallwiththermalinsulationcomposite systemcan achievea highdegreeof sound insulation againstexternalnoisebecausethe to loadbearing walldoesnotneedto contribute the thermalinsulationand can thereforebe The builtusinga heavytypeof construction. indexof a 175mm airbornesoundinsulation wallwiththermal thickcalciumsilicateexternal insulationcompositesystemliesbetween47 conand 51 dB dependingon the particular struction. 1, the posiAccordingto DIN4109supplement tive effectof a ventilatedfacademay not be takenintoaccountwhenassessing the sound insulation againstexternalnoise.Onlythe arearelatedmassof the innerleafis assumedto However, to the soundinsulation. contribute wallscan achieveconsiderably solidexternal indiceswith higherairbornesoundinsulation the ventilated facadescurrently available on thetypeof joints,typeof [167].Depending material construcinsulation and supporting walls tion,the soundinsulation of solidexternal withventilatedfacadesmay be increasedby up to ARw= 15 dB witha carefulconsideration relevant to building of all boundaryconditions acoustics.Fora twin-leafexternalwall,the airfrom indexis calculated bornesoundinsulation the sum of the area-related massesof both leaves. Thefollowing amountsmaybe added in thiswavfor thetwinto the valuedetermined leaftype of construction:

350

+1

150 -1 0

-1

Soundinsulation

to achievean airbornesound It is possible insulation indexof 55-66dB for cavity,partialwallsusingthe customary fillorfull{illexternal The resultsof investigaformsof construction. tionsintocalciumsilicatewallsshow,for the the effectsof the samewallconstruction, remaining airspaceandthetypeof insulation material [92].Usingrigidexpandedpolywith styreneboardsas the thermalinsulation producesa anairspaceof 40 mm (padialJill) result 2 dB higherthanfullcavityinsulation. Ontheotherhand,fillingthe cavitycompletely loose{ill withmineral fibreboardsor hyperlite resultsin a 2 dB advantage overrigid material exoanded olasticboards.

2.6,95 Resultingsound reductionindex R'*,.*.,""(dB) in relationto sound reductionindexof wall,sound reduction indexof windowand its proportionof the area (%) Wall:50 dB Window:35 dB at 25% windowarea proportion Facade:40 dB

50 dB

in dB for a windowarea proportion(%) Soundreduction SoLrndreCuctionindex of window R.^, " OE ID J5 0b 32 dB 30dB indexof wall 30% 2 5 % 5Oo/o 4Oo/o 3Oo/o 2 5 % 40% 50o/o 25% 3Oo/o 39 39 34 35 37 36 32 34 33 35 45 39 40 34 35 37 37 33 35 33 35 50 40 34 35 37 33 33 35 35 55 andard constructions for a windowarea propoftion Soundred. Soundreductionindexofwindow 45 dB 42 dB 40 dB index 37 dB 257;o 3Oo/o 4OVo 5O/o 25% 3ook 4Oo/o 5O/o 25o/o 254/o 3Oo/o of wall 48 44 48 45 46 43 46 43 45 44 a1 ag a2 a2 50 50 45 51 46 48 47 43 45 44 40 46 43 42 41 60 51 50 45 47 46 48 44 43 45 40 46 43 42 41 65 b) Externalwalls and windowswith high sound insulation

38 38 38

50o/o 37 37 37

SOa/o

49 49

47 48 48

Building science

2 . 6 . 9 6 _B u i l d i n gm a t e r i a l cs l a s s e st o D I N4 1 0 2p a r t 1 Buildrngmaterialsclass Buildilg authoritydeslsnglgn A incombustiblematerials A1 A2 B combustiblematerials B1 not readilyflammablematerials B2 flammablematerials B3 h i g h l yf l a m m a b l em a t e r i a l s -

Fire protection

2.6.97 Fireresistance.classes F to DIN 4102 Fireresistance Durationof fire ciass resistancein minutes FJU >30 F60 >60 F90 >90 F 120 > 120 F 180 > 180 ffi

2.6.98 Comparisonof qerman buildingmaterialsclasseswith futureEuropeanclasses Firesituation Productpedormance Europeanbuilding Extensivefire ln one room Singleobject on fire No spreadof flame to adjoiningsurfaces of a prod,uct

No contributionto fire VerVlimitedfire Limitedcontributionto fire

a!!9p!4!le !e!lr&!119

Acceptablebehaviourin fire

No performanceestablished

DIN 4 j02 building

The chieftasksof fire protectionareto prevent firesfromstartingand spreading, and should thathappen,to guarantee to opportunities rescuepersons,animalsand propertyas well as createthe rightconditionsfor effectivefirefighting.Thecompulsory buildingauthority requirements maybe supplemented by the requirements these of the insurers. Satisfying is notcompulsory but doesleadto marked premiums. reductions in insurance Besidesactiveflre-fighting measures, e.g. sprinkler systemsandfirealarms,the emphapreventive sis is on maintaining fireprotection throughconstructional measures(referredto as structural fireprotectiorl). Thisincludes guaranteeing for the adequatefireresistance components, usingmaterials thatdo notgenerate any,or at leastno excessiveamountsof, smokeor toxicgasesduringa fire,and reducingthe riskof firethroughcarefulplanning measures. The latterincludesthe arrangement of firecompartments; the safeguarding of escapeand rescueroutes;and meansfor ventingsmokeand heat. In Germanythe buildingauthority requirements regarding fireprotection are definedin the FederalStateBuildingCodessupplemented by statutes,bye-lawsand directives. The stanis DIN4102(18 dardcoveringfireprotection paris),whichcontainsbothtestingstandards for investigating firebehaviour and assessing and information on analysingfire protectionfor classified buildingmaterials and components.

Building material classes

2.6.99 Determination of fire resistanceclass,afterKordina/lvlever Ottens

Materialbehaviour High-temperature or combustionbehaviour of material, e.g. of concrete, steel,masonry,timber

Durationof fire resistance

Fireresistanceclass + Classof materialused uesrgnaton

196

The behaviour in fireis of buildingmaterials assessedand classified accordingto DIN 4102part1. Buildingmaterials areclassified accordingto theircombustibility as classA (see (incombustible) or classB (combustible) for table2.6.96), Theassessment criterion incombustible buildingmaterials of classA1 is theirbehaviour uponthe outbreakof a fire.lf buildingmaterials of classA 2 includecomthe spreadof flame,the bustiblecomponents, gasesandtheirtoxicity densityof conflagration mustbe evaluated. Thisis intended to ensure thatdespitecontaining combustible componentsthe overallbehaviour can be compared to the purelyinorganic A 1 materials, Combustiblebuildingmaterials areassessed with regardto theirflammability and rateof spread of flame,Buildingmaterials of classB 3 - high- can makea directcontribution ly flammable to the outbreakof fire and so the FederalOutlineBuildingCodeprohibits theiruse.Thetest for B 2 involves a small,definedflame,thetest for B 1 typicallyan objecton firewithinthe room(e.9.wastepaperbasketin onecorner). Thebehaviour of the buildingmaterialin fireis important for the buildingauthority requirementsfor two reasons.First,the materialmust

Fireprotection

meetrequirements whenit is usedas the sur(e.9,walland soffit faceof a component cladding); second,whenusedas partof the construction of a component.The essential partsof fire-resistant componentsmustconsist of incombustible materials, TheEuropean of classesfor thefirebehaviour productshavenowbeenacceptedby building theStandingCommitteefor the Construction Industry. Theywillbe publishedafterworkon thestandardand the associatedtest methods hasbeencompleted. A comparison between theEuropean and Germanbuildingmaterials liketable classescouldwelllooksomethinq 2.6.98.

2,6.100 Standardtemperaturecurve 9o

1200

@ 6

o

.g o f

6 o o-

-o

Rnn

fj

Standard

F

600

Fire resistance classes

Thesafetyof a structureduringa fire depends notonlyon the combustibility of the materials - on the durationof fire butalso- in particular resistance of the components. Thefireresis1s0 180 120 60 90 tanceclassof a comoonent is definedas the minutes of fire ln Duration minimum durationin minutesfor whichthe wlthstands component a specifiedfiretest.In a firetestthe sampleis subjectedto a precisely 2.6.101 Designationof fire resistanceclassesin conjunctionwith materialsused accordingto DIN 4102 paft 2 gradient, defined temperature the international-Fireresistance Buildingmaterialsclassto DIN 4102 pt 1 Designationz) Code ly standardized standardtemperaturecurve ctass 10 of the materialsused for (seefig.2.6.100), and is assessedaccording table 2.2.3-2 to thefollowing chieftestcriteria: essentialpartsr) otherparts not classed ' Maintaining the load-carrying capacity(stabilas essentialpartsr) of components ity) underloadfor loadbearing components of components CompongntsoI or self-weight for non-loadbearing compoF 3O.B Fireresistanceclass F 30 B F30 B nents. F 3O-AB Fireresistanceclass F 30 and B ' Maintaining permissible a maximum rateof with essentialparts made in the caseof components on deflection from incombustiblematerials') F 3O-A Fireresistanceclass F 30 and statically determinate supports. materials from incombustible made . Maintaining (integrity the roomenclosure and --I OLI-D Fireresistanceclass F 60 F60 insulation) in the caseof wallsso thatno F 60-48 Fireresistanceclass F 60 and gasescan escapeand no cracks ignitable with essentialpafts made from incombustiblematerialsr) The canformwhichmightleadto ignition. F 60-A Fireresistanceclass F 60 and increase in temperature on the sideremote matelials made from incombusJible fromthefireshouldnotexceed140"Con F 9O-B Fireresistanceclass F 90 F90 F 9O-AB measuring averageand 180'Cat individual Fireresistanceclass F 90 and with essentialparts made pornts. As can be seenin fig.2.6.99,the durationof fireresistance is essentially determined by the behaviour of the material and influences specificto the component. Inthe caseof masonry, failuretakesplacedueto the reductionin crosssectionresultingfromtemperature-related fatigueof the masonryunitsand dehydration of the mortar.The durationof fire resistance to be assignedto a fire enablesa component resistance class(seelable2.6.97).Component classifications can be coupledto material requirements withrespectto buildingmaterials c l a s s eas c c o r d i ntgo f i g ,2 . 6 . 1 0 1 inindividual cases. Thefireresistance with classesaredesignated differentlettersdependingon the type of comp o n e n(ts e et a b l e2 . 6 . 1 0 2 ) .

F 120

F 180

a

A

B B

from incombustiblematerialsr) Fireresistanceclass F 90 and made from incombustiblematerials -Fire resisunce class F 120 Fireresistanceclass F 120 and with essentialparts made from incombustiblematerialsr) Fireresistanceclass F 120 and materials made from incombustibrle Fireresistanceclass F 180 Fireresistanceclass F 180 and with essentialpads made from incombustiblematerialsr) Fireresistanceclass F 180 and made from incombustiblematerials

F 9O-A

i :zuB F 120-AB

F 120-A F 180-B F 180-AB

F 1BO-A

1) Essentialparts include: parts alsothe partsthat contributeto a) All loadbearingpads and thosecontributingto stability;for non-loadbearing walls). theirstability(e.9.framesfor non-loadbearing b) In enclosingcomponentsa continuouslayerin the componentplanethat may not be destroyedin the test accordingto this standard, In floorsthis layermust be at least50 mm thick in total;voids withinthis layerare permissible. Whenassessingthe fire behaviourof materials,surfacecoatingsor othersurfacetreatmentsneed not be considered, 2) This designationconcernsonly the fire resistanceof the component;the buildingauthorityrequirements for materialsused in fittinoout the lnterior,and which are connectedto the component,are not affectedby this.

197

Buildingscience

2.6.102 Codesfor designatingcomponentswhen specifyingthe fire resistanceclass Component Walls,floors,columns,beams Externalwalls Fireprotectionclosures,e.g. fire doors Ventilationducts,fire stops (fireprotectionclosures) Glazing

Types and functions of walls Code for designating fire resistanceclass F T

L+< G

2.6.103 Typesof walls:examplesof plan layoutsfor residentialand industrialbuildings,afterHahn

R e s i d e n t i ablu i l d i n g ApartmentI l - -

+< 1.0i4)

I n d u s t r i abl u j l d i n g

T-

R l' + l

Lttr

l>1.0(,

@

L o a d b e a r i n ge,n c l o s i n gw a l l s

@

Loadbearing,non-enclosing wars

@

Non-loadbearing,enclosingwarrs

@

Shortwalls,formerlydesignatedas piers

Apartmentll

A p a r t m e nltl l

ln termsof the functionof a wall,for fire protectionpurposeswe distinguish betweenloadbearingand non-loadbearing, and between walls.Figure enclosing and non-enclosing 2.6..103 illustrates thesetermsusingpractical examples[68]. A non-loadbearing wallis a platetypecomponentthat- also in the caseof fire* is essentially loadedby its ownweightand doesnot prowalls. vide bucklingrestraint to loadbearing However,it musttransferwind loadsactingon its surfaceto loadbearingcomponents. A loadbearingwallis a plate-typecomponent mainlyloadedin compression for carryingboth verticaland horizontal loads.Wallscontributing to the stability of the buildingor otherloadbearing components as loadareto be considered bearingwallsfromthe pointof viewof fireprotection. An enclosingwallis a wall,for example,along an escaperoute,adjacentto a staircase,or a partywall or firewall.Suchwallsserveto preventfire spreadingfromone roomto the next and are thereforesubjectedto fire on onlyone side.Enclosing wallsmaybe loadbearing or non-loadbearing. wallis a wallsubjectedto fire A non-enclosing on two,threeor foursidesduringa fire.

Firecompartments

, f < r . o@ +

Directionoffloorspan Requirements

2.6.104

Overviewof buildingauthorityfire protectionregulations

Buildingsand structuresof special types for specialpurposes

Placesof assembly,garages, businesspremises,hospitals, high-rise b u i l d i n g ss, c h o o l s , i n d u s t r i abl u i l d i n g s

D t N4 1 0 2 D t N1 8 0 8 1 DtN18230

198

Thefundamentals fireproof buildingauthority tectionrequirements are contained in the respectiveStateBuildingCodesand the associatedstatutes, as wellas in technicalbuilding provisions and administrative rules.Figure 2.6.104explainsthe relationships and mutual influences. All StateBuildingCodes,the correactsand administraspondingimplementation tive rulesmakea distinctionbetweennormal for normalpurposes, buildings e,g.housing, for special and thoseof specialconstruction purposes, hospitals, e,g.placesof assembly, industrial buildings. Normalbuildings for normalpurposesmakea distinctionbetweenthe differenttypesof buildings.Theclassification in buildingclasses a c c o r d i ntgo f i g .2 . 6 . 1 0 5 d e p e n d so n l a d d e r accessfor thefirebrigadeand so is directly relatedto the heightof the building. Buildings or for special of specialconstruction purposesaredealtwithonlyin principlein the buildingcodes.TheStateBuildingCodesare complemented by specialactsand directives thattake intoaccountthe soecialcircumplacesof stancesof high-rise buildings, restaurants, hospitals, assembly, business premises, buildings. schoolsand industrial Therelationship betweenthe requirements padlydescribedin the StateBuildingCodes accordingto and the abstractclassification oart2 and otheroartsof DIN4102is carried in outon the basisof the definitions contained someStateBuildingCodes,or accordingto

Fireprotection

Therela- 2 , 6 . 1 0 5 C l a s s i f i c a t i oonf b u i l d i n g si n f i v e b u i l d i n gc l a s s e sa c c o r d i n gt o t h e b u i l d i n gc o d e s thelistof standardbuildingmaterial. lawand DIN4102 tionshiobetweenconstruction B u i l d i n gc l a s s 3 The primarycom is givenin table2,6.106. High-rise ponentof thefiresafetyconceptin the building L o w - r i s eb u i l d i n g s Free-standing Other buildings LadderaccessH<8m r e s i d e n t i ablu i l d i n g buildings principle: fire codeis the compartmentation H > 8 m > 3 holsing units t h o u s i n gu n i t < 2 housingunits shouldbe restrictedto as smallan areaas possible. is the F o r F F L> 7 m < 2 2 m At least1 occupied Thefirst"firecompartment" Firebrigadeaccess possible room > 22 m with scalingladderfor FFL< 7 m in an functional unit,e.g.a wholeapaftment above FFL apartment block,boundedby the floors,party F F L< 2 2 m wallsandstaircase walls.At the veryleast,the fireshouldnotspreadto neighbouring buildhigh ings,whichcan be achievedby relatively requirements beingplacedon thefirewalls.In theStateBuildingCodesdemand addition. thatlargebuildings themselves be subdivided intofirecompartments. However,the compartprinciplecan be fullyeffective mentation only for the useof whentheopeningsnecessary closed.Thisapplies building areappropriately to DIN 4102 and constructionlaw 2,6.106 to buildingservicepenetrations, e.g.electric Buildingauthority 41 designation cables,pipes,as wellas to openingssuchas Fire-retardant F 30flaps,doorsand gates. Fireresistanceclass F 30 -AB Fire-retardant Fireresistanceclass F 30 with A numberof primaryfire protectionrequireloadbearingparts made parts made from in residential buildings essential mentsfor components incombustiblematerials Theexamplegiven aregivenin table2.6.107. #tql4s F3o4 Fireresistanceclass F 30 and hereis takenfromthe StateBuildingCodefor made from incombustiblematerials Fire-resistant F 9O-AB (thereare sometimes Fireresistanceclass F 90 with NorthRhine-Westphalia essentialparts made from slightdifferencesbetweenthe codesof the incombustiblematerials federalstatesin Germany); this individual and Fire-resistant F 9O-A Fireresistanceclass F 90 and made from incombustiblematerials for all made from incombustiblematerials building codewas adoptedin itsentirety thefederalstatesof formerEastGermany. withone Free-standing residential buildings h o u s i nugn i t( b u i l d i ncgl a s s1 )a r en o ti n c l u d e d inthetablebecausethereareno requirements forthefire resistanceclassesof componentsin However, the basicrequiresuchbuildings. 2,6.107 Summaryof the most importantrequirementsfor structuralfire protectionfor componentscustomaryin BuildingCode as an example ment,thatno highlyflammable buildingmaterbuildingsusingthe NorthRhine-Westphalia C l a s so f b u i l d i n g, ialsmaybe employed, stillapplies,ConseO t h e rb u i l d i n g s Anybuilding Residential Type of quently, thethermalinsulation materials used apartfrom building thermalinsulainwallswithexternal or internal from high+ise of low height(FFL< 7 m) buildings > 3 h o u s i n gu n i t s < 2 h o u s i n gu n i t s , masonry withadditional tionlayerandtwin-leaf 0r) Ort Roof 01) thermalinsulationbetweenthe masonryleaves Loadbearingwalls F 9O-AB F 3O-ABA F 3O-B Other classB 2 mustcomplywithbuildingmaterials Fs94E_ F 9O-AB F 3O-AB Basement or higher. A or F 30-B externalwalls Non-loadbearino 0 B 2 ->suitable F 9O-AB (F 30-B) +

Externalwall Cladding

Firewalls

Firewallsaccordingto DIN4102part3 must complywiththefollowing enhancedrequirements: .Theymustbe builtfrommaterials of building materials classA to DIN4102part1. .Theymustcomplywiththe requirements of fireresistance classF 90 or higherto wallsmust DIN4102part2; loadbearing satisfy thisrequirement underconcentric andeccentricloading. . Firewallsmustremainstableandfulfiltheir to an enclosing functionafterbeingsubjected impactload(3 x 200kg of leadshotin sack). However,it is not onlyadequateto ensurethat - they firewallscomplywithtest requirements mustbe properlylocatedin practiceand properly constructed.

B u i l d i n ge n d w a l l s

B1

BW F 9O-AB

/tron_R\

Floors

Parly wails 40m Party walls betuueen

qpgg!9q9 Staircase

-

0rt F 3O-B

Roof Other Roof Floor Walls

F 3O-B F 3O-B 0 0 0

0r) F 30-AB3) F 9O.AB BW F 9O.AB F 3O-B F 60-48 0 F 3O.AB F 9O.AB

Walls

-

F 30-B

F 30-AB

0 0

F 3O-AB A F 9O-AB A

sat, flonorallv annocqihla

0r) F 9O-AB F 9O-AB BW

Roof Other Basemenl

F 3O-B FgO-AB F 9O-AB

itgqt=

corndorsas Cladding routes Walls,floors Open walkways Cladding adjacentexternalwalls 1)Insideof roof F 30-B for buildingswith gable facing the street 'z)F 30-Bfor buildingswith < 2 storeysabove ground level 3tF 30-Bfor buildingswith < 2 storeysabove ground level atlove ground level F 30-B/Afor buildingswith > 3 s.toreys

F 3O-B F 9O-AB 0 F 9O-AB BW

199

Bulldingscience

2.6.108 Fireprotectionrequirementsin the vicinityof fire walls Component ReqLlirements

Thefire protectionrequirements for firewalls aresummarized in 2.6.108.DIN4102oart4 containsdetailsof permissible slenderness ratiosand minimumthicknesses of firewalls withothercomponents. and theirjunctions

WAIIS

Loadbearingand bracingcomponents No. of openings Closuresto openings

+ impact load 3 x 3000 Nm F90 No restriction T 90 doors (self-closingmechanism) F 90 fire protectionglazing S 90 fire stop to cable penelrations

Complex party walls

nrr"ng The respectiveFederalStateBuildingCode must be adheredto

Betweenbuildingsforminga terrace W i t h i nl a r g eb u i l d i n g s Dependingon heightof buildingand roof covering: < 3 full storeysextendingto undersideof roof covering > 3 full storeys at least 300 mm above roof soft roof covering at least 500 mm above roof Componentsmay intrude,providedthe remainingcross-section of the wall remainssealedand stableto F 90 standard.

Complexpartywallsare merelyreferredto in a footnotein DIN4102part3 becausethisis an insurance industryterm,Themainpointto be notedis thatthe provisionsof the insurers, with limitations on openings, callfor fireresistance classF 180,Complexwallsmustpassthrough all storeyswithoutany offsets.Components may notintrudeintonor bypassthesewalls..

Classification of proven components 109 Fire

for ventilated c Requiredbuildingmaterialsclassto 4 n<2fullstoreys n > 2 f u l lstoreys,

high-rise buildings

Cladding B2 B1 S u p p o r t i n g c o n s t r u c t i o nB 2 B 2 1)2) Thermalinsulation B2 B1 A3) Means of Aqt A4) ' ) T h e r ea r e n o r e s t r i c t i o nosn u s i n gB 2 b u i l d i n g trame-likesuppofiingconstructions,providedthe gap betweencladdingand insuiationdoes not exceed 40 mm and window/doorrevealsare protectedby class A building materials. '?)The BavarianBuildingCode permitstimber supportingconstructionsfor buildingsup to 30 m high. 3) Does not apply to elementsfor retaininglayersof insulation. a) Does not apply to anchorsystemscoveredby a buildirigauthoritvcertificate,

2 . 6 . 1 1 0 S i n g l e - a n d t w i n - l e a f f i r e w a l l s t o D l N 4 1 0 2 p a r t . 4 | a b l e 4 5 , P e r m i s s i b l e s l e n d e r n e s s , mt hi ni c. w k nael l s s and min, spacingof leaves(fireload on one side).Valuesin bracketsapply to wallswith plaster,Designto .l DIN 1053 parls and 2 with permissibleslendernessratioho/d.The eccentricitye may not exceed cll3. Type of wall Masonry withoutplaster with plaster Min,thicknessd (mm) for single-leal twin-leaf6) construction construction Wallsof masonry3r to DIN 1053 parts 1 and 2 using normal-weight mortarof mortargroup ll, l l a o r l l l ,l l l a . Masonryunitsto DIN 105 part 1 of gross densityclass > 1.4 240 2x175 .1.0 > 300 2x2OO (240) (2 x 175) DIN 105 pad 2 of grossdensityclass > 0,8 JOC'' 2 x24O x1 u n i t st o D I N 1 0 6 p a r t 1 ' )a n d D I N 1 0 6 2 x 1755) part 1 A1 " as well as part 2 of grossdensityclass > 1.4 240 2x175 > 0.9 300 2 x2OO (300) (2 x 175) 300 2x240 x17 unitsto DIN 4165 of grossdensityclass > 0.6 300 2 x24O > 0.64) (2 x 175) 240 > 0.56) 300 2x Masonryunitsto DIN 1 18152 and > 0.8 240 X1 of grossdensityclass (175) (2 x 175) > 0.6 300 2 x24O (240\ (2 x 175) 'r Also with thin-bedmortar. 2)d = 175 mm when usingthin-bedmofiar and gauged brickwork. 3tUtilization factord2 < 0.6 when using lightweightmortar. o)Appliesto thin-bedmortarand gauged brickworkwith mortarto perpends and bed joints. 5)d = 150 mm when usingthin-bedmortarand gauged brickwork. 6)Appliesto thin-bedmortarand gauged brickworkwith tongueand groove only in the case of mortarto perpendsand hcd

200

ininiq

DIN4102part4 containsdetailsof building materials,componentsand specialcomponentswhosefire behaviourhas beenclassified on the basisof tests.Theproductsincludedin the standardhavealreadybeenverifiedin termsof theirbehaviourin fire.Thefire protection classification of the wallsis carriedout accordingto: 'wall material . wallthickness . type of fire (fromjust one side or frommore thanoneside) ' utilization of the load-carrying capacityof thewall lf a componentis notfullyutilized,its load-car-ryingcapacityduringa fireis greaterthan whenit is utilized100%.Therefore, in the stanfacdard we distinguishbetweenthe utilization tors o, = 1.0 (100% utilization), dz = 0.6 (60% The utilization) and c[',= 0.2 (2Oo/o utilization). classification of walls,shallowlintelsand channel blocksfilledwith concretecan be foundin tables38-42of DIN4102part4. The informationin thetablesappliesto masonryaccording to DIN1053.Plasteron the sidefacingthefire prolongsthe durationof fire resistance. The valuesin bracketsin the tablesrelatingto wall thicknessesreferto olasteredwallsbecause certainplastershavea positiveinfluenceon the fire behaviourof masonrywalls.Twin-leaf wallsonlyrequireplasteron the outerfaces. Thetablesare validfor all typesof perpends accordingto DIN 1053part1, i.e.for perpends fullyfilledwithmortar,for "tippedandtailed" perpends,and perpendswithoutmortar(interin lockor tongueand groove).Perforations masonryunitsor wall panelsmay not run perpendicular to the planeof thewall. Masonryreadilysatisfiesthe requirements of fire protection,generallythroughthe wallthicknessrequiredfor structural or buildingscience reasons.Therefore, the extensivetablesin DIN 4102parl4 can be considerably reducedby specifying fireresistance classF 90 and 100%

Fireprotection

degreeof utilization. Tables2.6.111-1'13 sperequiredto cifytheminimum thicknesses achieve fireresistance classF 90 employing masonry of standardunits.Besidesthe fire resistance class,firewallsmustalsocomply givenin table2.6,110with withtheconditions regardto slenderness ratioand wallthickness. maynotbe usedin orderto reduce Claddings thesoecified wallthicknesses. Thinnerwalls thanthosegivenin DIN4102part4 havebeen provedfor firewallsof clay,calciumsilicate, autoclaved aeratedconcreteand lightweight concrete unitsin teststo DIN4102part3 [7, 76,134,2091. Reference [67]containscomprehensive information on fireprotection in masonrystructureswith practicalexamples.

wallcladdingsuponwhichdoubthasbeen castby certaintests[22]. materials of buildingmateriThermalinsulation alsclassB 2 maybe usedup to the high-rise cavitywalls. buildinglimitfor partial-or full-fill In contrastto this,buildingsof mediumheight (7-22m) requirethatcontinuous layersof F 30AB and F 90-ABcomponentsmustconsistof materials. c l a s sA b u i l d i n g materials of building insulation Flammable materialsclassB 2 are permittedin the caseo1 for buildingsup Io 22 m internalinsulation applyto escape height.Specialregulations roules.

Single-leaf external wallswithan external, renderedthermalinsulation layer(thermal insulationcompositesystem)are assessedin fire protection termsaccordingto the type of insulationmaterial used.

systemswith Thermalinsulation composite insulation materials of notreadilyflammable polystyrene particlefoam(buildingmaterials thickness of 100mm classB 1) and a maximum witha generalbuildingauthority complying certificatemay be usedon masonryup to the high-rise buildinglimit.Thermalinsulation composite systemsusingmineralmaterials, e.g.mineralwoolproductsof buildingmateras a coat ialsclassA 1 or A 2. areconsidered thewall.In termsof of plasterwhenclassifying wallis equivalent fireprotection, the external wallwithoutthermalinsulation. to a plastered Thermalinsulation composite systemswith materials class insulation of buildingmaterials witha B 2 maybe employedonlyon buildings maximumof two full storeys.The fire protection facades requirements for curtainwallventilated d e p e n do n t h eh e i g hot f t h e b u i l d i n gt h; e requirements withrespectto buildingmaterials classesfor facadecomponentsare summarizedin table2.6.109. Thefireprotection external requirements stillapplyfor ventilated

2.6.111 Loadbearing,enclosingwallsof masonryto DIN 4102 part 4 table 39. Valuesin brackets apply to walls plasteredboth sides.Utilization factorcr, = 1.9 Constructionfeatures M i n .t h i c k n e s s( m m ) for fire resistance o. class F 90

2 . 6 . 1 1 2 M i n .t h i c k n e s sd o f l o a d b e a r i n gn,o n - e n c l o s i n g 2.6.113 Non-loadbearing, enclosingwallsof masonry wallsof masonryto DIN 4102 part 4 table 40 or wall panelsto DIN 4102 part 4 table 38. (fireload on morethan one side).Valuesin Valuesin bracketsapply to walls plastered bracketsapply to walls plasteredboth sides. both sides Utilizationfactoru, = 1.6 Min.thickness(mm) Constructionfeatures for fire resistance M i n .t h i c k n e s s( m m ) Constructionfeatures class F 90 for fire resistance

Externalwalls with thermal insulation

77-lo'

Z

-d1

Walls Autoclavedaerated concrete Blocks& gauged brickwork t o D I N4 1 6 5 Grossdensityclass> 0.5

175 ( 15 0 )

1)2)

r)3)

Claybricks Solid& verticallyperforated t o D I N1 0 5p t 1 u s i n gr r Claybricks Lightweight & vefticallyperforated t o D I N1 0 5p t 2 Grossdensityclass> 0.8

t/c

class F 90

Autoclavedaeratedconcrete B l o c k s& g a u g e db r i c k w o r k t oD I N4 1 6 5 Grossdensityclass> 0.5 u s i n gr ) 2 ) I i^hh^,di^h+

Lightweight concrete H o l l o wb l o c k st o D I N 1 8 1 5 1 S o l i db r i c k s& b l o c k st o D I N 1 8 1 5 2 175 Concretemasonryunitsto DIN 18153 ( 1 4 0 ) Grossdensityclass> 0.6

d1 d dl

m

240 ( 17 5 )

^^n^r6t6

H o l l o wb l o c k st o D I N 1 8 1 5 1 S o l i db r i c k s& b l o c k st o D I N 1 8 1 5 2 Concretemasonryunitsto DIN 18153 Grossdensityclass> 0.6

240 ( 17 5 )

usinqr)3)

Clay bricks Solid& verticallyperforated t o D I N 1 0 5p t 1 1

( 115 ) Lightweight verticallyperlorated t o D I N 1 0 5p t 2 Grossdensityclass > 0.8 u s i n g1 ) 3 )

t)3) Parfnratinnt\/naaARR

( 11 5 )

Perforatjon types A & B

Lightweightvertically perforated

124o'\

Calciumsilicate Solid,perforated,blocks,hollow blocks& gauged brickworkto D I N1 0 6p t 1 & ' l A 1 F a c i n gb r i c k st o D I N 1 0 6 p t 2

115 ( 11 5 )

Lightweight vertically perforated brickstype W Utilizationfactor02 = 1.0 eablnm-ilil Solid,perforated,blocks,hollowblocks& gauged brickworkto DIN 106 pt 1 & 1 A1 D I N 1 0 6p t 1 A 1 Facingbricksto D I N1 0 6p t 2

1)2)4\

1)Normal-weight mortar 'ztThin-bedmortar 3tLightweightmortar a)The valuesapply only to masonryof solid bricks, blocksand gauged brickworkwhen 3.0<exrsto<4,5N/mm'?.

(115)

(24o)

mm Walls 1001) Autoclavedaeratedconcrete Blocks& gauged brickworkto DIN 4165 (75) Panels& gauged brickworkelements t o D I N4 1 6 6 95 Lightweightconcrete (70) H o l l o w w a lel l e m e n t st o D I N 1 8 1 4 8 H o l l o wb l o c k st o D I N 1 8 1 5 1 S o l i db r i c k s& b l o c k st o D I N 1 8 1 5 2 W a l le l e m e n t st o D I N 1 8 1 6 2 u n i t st o D I N 1 8 1 5 3 Concrete ttc Clay bricks Solid& verticallyperforated (100) t o D I N 1 0 5p t 1 Lightweight verticallyperforated t o D I N 1 0 5p t 2 High-strengthbricks& engineering b r i c k st o D I N 1 0 5 p t 3 High-strengthengineeringbricks t o D I N1 0 5p l 4 11 5 C a l c i u ms i l i c a L e (100) Solid,perforated,blocks, hollowblocks& gauged brickwork toDIN106ptl&1Al G a u g e db r i c k w o r k t oD I N 1 0 6 p t 1 & DIN106 pt 1 A1 F a c i n gb r i c k sl o D I N 1 0 6p t 2 r) d > 50 mm when usingthin-bedmonars.

140 ( 11 5 )

1t2)

1)Normal-weight mortar 2)Thin-bedmortar 3)Lightvveight mortar a)The valuesapplyonlyto masonryof solidbricks,blocks and gauged brickworkwhen 3.0 < exjsto < 4,5 N/mm2.

201

Variables

Units and symbolsfor buildingscience Symbol

Designation

Unit m2

F^

O Qn

O"

Moisturecorrectionfactor ReductionJactorfor sunshading Specifictransmissionheat loss Heatconduction

wK

Heat,heat energy

JorWs

Annualheatingenergyrequiremenl Annualheatingrequirement Heat gain

kWh/a

wn< kWh/a kWh/a kWh/a

o

Heat loss Primaryenergyrequiremenl

O

Energyrequirementfrom renewablesources

kWh/a

Q1

Total heat losses due to heating system Energyrequirementfor hot water provision

kWh/a

Qr

O*

Thermalresistance Internal,/External surface resistance Totalthermalresistance(air-to-airresistance) Solarheat penetration U (formerlyk in Germany)

u,^,

Thermaltransmittance Thermaltransmittance, windowframe Thermaltransmittance,glazing Thermaltransmittance, window Volume

kWh/a

kWh/a m2KlW m2KNl m2KAA/

W/m2K W/m2K Wm'?K W/m2K m3

Watervapourdiffusionresistance

m'?hPa4
Temperaturediffusivity Heat penetrationcoetficienl

J/m'?Kso5

Specificheat capacity Thickness Cost index relatedto primaryenergyrequiremenl

m2/s

J,&gK

Temperaturefactor Solartotal energytransmittance Watervapourdiffusionflow rate Thermalsurfaceresistancecoefficient

kg/m'h W/m'?K kg

ffiwv

Mass Area-relatedcondensationmass Area-relatedevaoorationmass

No,,tr

P' P"

Air change rate Watervapourpartialpressure,

Pi,P"

watervapoursaturationpressure Watervapourpartialpressure,internal/external

Pa Pa

Heat flow rate Watervapourdiffusion-equivalent air layerthickness Time

W/m2

kg/kg

'4 (eta)

Mass-relatedmoisturecontent Waterabsorptioncoefficient Degreeof utilization

$ (theta)

Temperature

.C

Air temDerature. internal/external

.C

Internalsurfacetemperature Thermalconductivity Watervapourdiffusionresistanceindex

.C

Gross/bulkdensity Heatflow Relativehumidity

kg/m3

I (chi)

Discretethermaltransmittance

WiK

v (psi)

Linearthermaltransmittance Volume-related moisturecontent Soundjntensity

WmK

s

m3/m3

h

W/m2

P

Soundoressurelevel.sound level Soundreductionindex

dB

kg

Pascal kilogram

dB dB

'c

d

day

t1z

dB

Pa

Hz

decibel Heftz

ffiwr

r1 . L (lambda)

p (mv) p (rho) O(phi)

R,n,

202

Airbornesound insulationinde^ Frequency Sound pressure

kg/m2

kg/m2

kglm2ho 5

m

mere Watt

K

Kelvin

J

JOUIe

year second hour

degreeCelsius