Mechnical Systems Design Criteria For Labs.docx

MECHANICAL SYSTEMS DESIGN CRITERIA FOR LABS

April, 2018 Rev: 00

Mechanical Systems Design Criteria

Contents A.

HVAC SYSTEM.........................................................................................................................................................1 1.

General...............................................................................................................................................................1

2.

Method of calculation........................................................................................................................................1

3.

Geographical location of the project site..........................................................................................................1

4.

Ambient design conditions................................................................................................................................1

5.

Codes and Standards.........................................................................................................................................1

6.

Indoor Design Conditions..................................................................................................................................2

7.

Indoor heat generation......................................................................................................................................2

8.

People Density...................................................................................................................................................2

9.

Room Pressurization Requirement....................................................................................................................2

10.

Noise Control.................................................................................................................................................3

11.

System description........................................................................................................................................3

12.

Room pressure control..................................................................................................................................5

13.

Fire and smoke control..................................................................................................................................6

14.

Chilled water system.....................................................................................................................................6

15.

Materials of construction..............................................................................................................................6

B.

PLUMBING..............................................................................................................................................................7 1.

General...............................................................................................................................................................7

2.

Codes and Standards.........................................................................................................................................7

3.

Incoming Connections.......................................................................................................................................7

4.

Labs Cold and Hot Water Distribution:..............................................................................................................7

5.

Water Supply Sizing Criteria...............................................................................................................................8

6.

Piping Material...................................................................................................................................................8

7.

Drainage System................................................................................................................................................8

C.

FIRE FIGHTING........................................................................................................................................................9 1.

Codes and Standards.........................................................................................................................................9

2.

Incoming Connections.......................................................................................................................................9

3.

Fire System for Labs...........................................................................................................................................9

4.

Fire Piping Material............................................................................................................................................9

B.

Piped Gas services................................................................................................................................................10 1.

Codes and Standards.......................................................................................................................................10

2.

Medical Gas system for Labs............................................................................................................................10

3.

Medical Gas Piping material and sizing:..........................................................................................................10

EA Consulting Pvt Limited

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Mechanical Systems Design Criteria

A.

HVAC SYSTEM 1.

General This section outlines the design fundamentals to be used in the calculation of air conditioning loads and describes the methodology to be followed for design of HVAC system for the Microbiological, Epidemiological and Nutrition Lab (BSL 2).

2.

Method of calculation The cooling load of the building will be calculated based on Carrier E20-II Hourly Analysis Program (HAP). A 10% safety factor will be applied to all room sensible and 5% latent heat gains. Similarly, a 3% safety factor will be applied for duct heat gain and 5% for duct air leakage.

3.

Geographical location of the project site City: Karachi North latitude East longitude Altitude/Elevation

4.

25° 67° 13 ft

Ambient design conditions Summer Dry bulb temperature Wet bulb temperature Daily range

104°F (40°C) 83°F (28.3°C) 20°F (11.1°C)

Winter Dry bulb temperature 5.

44.1°F (6.7°C)

Codes and Standards The design and construction of HVAC system will be based on the following Codes and Standards: ASHRAE

-

American Society of Heating, Refrigerating and AirConditioning engineers, USA

NFPA

-

National Fire Protection Association Standards. USA

SMACNA

-

Sheet Metal and Air-Conditioning Contractors National Association, Inc., USA

ASTM

-

American Society for Testing and Materials, USA Page |1

Mechanical Systems Design Criteria

6.

IEEE

-

Institute of Electrical & Electronic Engineer, USA

NEMA

-

National Electrical Manufacturers Association, USA

UL

-

Underwriters’ Laboratories, Inc. USA

Indoor Design Conditions The User’s data provided for Microbiology, Epidemiology & Nutrition research lab gives key equipment operating requirements as under: Operating temperature range

:

50°F to 95°F (10°C to 35°C)

Operating humidity range

:

20% to 80% (non condensing)

No specific requirements have been given by the User for BSL 2 lab. ASHRAE recommends indoor design conditions as under: Laboratories Dry bulb temperature Relative humidity Air change per hour Fresh Air change per hour

: : : :

70°F to 75°F (21°C to 24°C) 30% to 60% 6 minimum 2 minimum

: : :

Not specified Not specified 10 minimum

Glass wash area Dry bulb temperature Relative humidity Air change per hour

Following design conditions for various spaces are considered in HAP (Hourly Analysis Program) calculations: • • • 7.

Central Cooling- Supply Air Temperature: 52°F Cooling T-stat Set points: 72°F Heating in winter is not required in Karachi.

Indoor heat generation The heat dissipation from laboratory equipment to be provided by biomedical engineering department.

8.

People Density The occupancy for labs and other areas is taken from furniture layouts shown in the architectural plans. For the areas where furniture layout is not shown, occupancy is calculated from ASHRAE std. 62.1-2013

9.

Room Pressurization Requirement In general, the Microbiology lab, Epidemiology lab and other BSL 2 labs on third floor will be designed to be at negative pressure. The Nutrition Research Lab (NRL) shall be positively pressurized.

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Mechanical Systems Design Criteria

10.

Noise Control The air-conditioning systems will be designed to provide low noise levels in all areas as recommended in ASHRAE handbooks, Code #. The sound levels will be as under: SPACE NAME Microbiology Lab Epidemiology Lab Nutrition Lab Glass wash area

11.

NC LEVEL 40-45 40-45 40-45 45-55

System description The air-conditioning system shall be designed keeping in mind the energy conservation techniques to benefit both the client and environment. The following energy conservation measure shall be considered. 

VFD booster Chilled Water Pumps



AHU’s with VSD’s to vary AHU air flow as per Load requirements



Variable Air Volume (VAV boxes) As required by the User, independent AHUs will be provided for Microbiology lab, epidemiology lab, nutrition research lab and Clean Corridor. Ambient outdoor air shall be mixed with return air in the mixing box of air-handling units. Tempered fresh air may also be provided to the air handling units but decision to be finalized by AKU. The labs and other critical areas where interruption in air-conditioning is unaffordable, dual coil AHUs are proposed i.e. in case of chilled water supply failure, the DX-coil of AHU with matching condensing unit will serve during unexpected failures and unforeseen shutdown. The AHU will comprise of the following components in sequence:

o o o o o

Pre filters (G 4 type) Bag filters (95% efficiency) Chilled water coil DX-coil (only for labs as a standby) + Condensing unit Supply air fan The supply and exhaust fans will be interlocked and their speed will be regulated by VFDs. The supply air will be provided in the lab through diffusers maintaining low velocity and sound level.

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Mechanical Systems Design Criteria

In general, the exhaust air from labs will be exhausted into atmosphere by the exhaust fans located at roof. For specific cases, e.g. contaminated or hazardous fumes, the exhaust duct from lab to HEPA filters will be of shortest run for safety of operating personnel. The air after passing through HEPA filters will be exhausted into atmosphere. Microbiological, Epidemiological & NRL Labs Keeping in view the functionality of microbiological lab, epidemiological lab and nutrition research labs each lab shall be provided with dedicated AHUs which will cater for its respective areas. AHUs will be re-circulation type and ambient fresh air will be mixed with return air in the mixing box.

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Mechanical Systems Design Criteria

Some specific exhaust requirements of particular rooms are as follows: S.# 1

Room Name Atomic absorption closed cubicle room

2

Sample receiving room

3

Cryo room liquid nitrogen Media room Sample processing room

4 5

6

ELISA Room

7

Nucleic Acid extraction (DNA)

8

Nucleic Acid extraction (RNA)

9

PCR Clean area

Requirements  General room exhaust  Hood exhaust for fumes of acid base cabinet (without HEPA)  Hood exhaust for graphite furnace  Bio Safety Cabinet (BSC) – A2 Type II hood (ductless exhaust) with built-in HEPA filters for supply and exhaust  General room exhaust  General exhaust required for water bath  Bio Safety Cabinet (BSC) – B2 Type hood (ducted exhaust) with HEPA filter in exhaust duct  Hood exhaust for fumes of acid base cabinet (without HEPA)  Bio Safety Cabinet (BSC) – A2 Type II hood (ductless exhaust) with built-in HEPA filters for supply and exhaust  Bio Safety Cabinet (BSC) – A2 Type II hood (ductless exhaust) with built-in HEPA filters for supply and exhaust  Bio Safety Cabinet (BSC) – A2 Type II hood (ductless exhaust) with built-in HEPA filters for supply and exhaust  Hood exhaust for fumes of acid base cabinet (without HEPA)

Dish wash area Exhaust air will be taken from above the washing sinks and autoclave to control spread of foul smell. 12.

Room pressure control In general, microbiological lab and epidemiological labs shall be maintained under negative pressure and nutrition research lab shall be maintained at positive pressure.

13.

Fire and smoke control

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Mechanical Systems Design Criteria

All central air handling units (AHUs) shall be interlocked with fire and smoke sensors mounted in supply and exhaust air ducts to shut down the AHU on sensing of smoke/fire and give audio alarm in the control room and indication on fire panel. Fire dampers with fusible links as per NFPA will be provided in supply duct crossing MER floor. 14.

Chilled water system The WCH-COE building is located near the NazerAli Walji building of AKUH. The chilled water for air conditioning shall be drawn from the central chiller plant, located in the service building. The chilled water will be tapped from existing chilled water pipes passing through the services tunnel of NazerAli Walji building. As the anticipated incoming Chilled Water pressure will be low therefore, booster Chilled water pumps (1-Duty & 1-Stand By) are proposed in basement-1 Plant room to distribute chilled water throughout the building. The pumps shall be provided with Variable frequency drive (VFD) to adjust as per building chilled water demand and to conserve power. The VFD pumping system shall operate using the principal of speed control based on constant pressure. The Pumps shall be interlinked with AKU central BMS system.

15.

Materials of construction Ducting for laboratories Duct insulation

: Galvanized steel : Fiberglass

Chilled water piping

: Black steel

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Mechanical Systems Design Criteria

B.

PLUMBING 1.

General This section outlines the design fundamentals to be used in the calculation of Plumbing system and describes the methodology to be followed for design of systems for Molecular (BSL 2) labs in WCH. This report is intended only for the Labs and have to be read in conjunction with “MEP Basis of Design report Rev-01”

2.

Codes and Standards The Plumbing systems for Labs shall be designed to comply with the following codes. i. ASPE handbooks Vol-3 (Ch-2 for healthcare facilities and labs) ii. NFPA-99 for Healthcare facilities iii. HTM Guidelines for Healthcare system Design

3.

Incoming Connections. As confirmed by AKU, the incoming cold and hot water shall be tapped from hospital existing network running inside the AKU utility tunnel. All incoming water connection shall be provided with water meters interlinked with BMS system. NO underground or overhead water reservoir is proposed for the building.

4.

Labs Cold and Hot Water Distribution: Up-feed water supply system shall be designed for the building. Both cold and hot water supply networks shall be provided with a dedicated boosters which shall be used to boost water to all Labs, Wet areas, Pantries and the rest of facility. Both Booster pump sets shall be located in Basement-1 Pump room. The booster pump shall be provided with Variable Frequency drive to adjust as per building Water demand in Peak and Off Peak hours and to conserve power. Isolating valves will be provided for isolation of service to each lab. Back flow preventers will be provided as required for hazard areas to prevent backward flow of contaminated water. A hot water circulation system shall also be designed to ensure the availability of hot water at all times. Hot water circulation pump shall also be located in Basement-1 plant room

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Mechanical Systems Design Criteria

5.

Water Supply Sizing Criteria Water supply piping shall be sized on hospital plumbing fixtures as per ASPE -3 Handbook Table 2-2. All laboratory sinks shall be 316 S.Steel and shall be provided with both Cold and hot water supply. The booster pump shall be sized to ensure that a minimum pressure of 20 psi is maintained at the most remote outlet as per final fixture selection. Hot water shall be distributed at 55-60 Deg. C ASPE -3

Design Basis

Equipment

Chapter -2 Table 2-2 Fixture Unit Method for labs External Water Supply Network 20 Psi @ Remote Outlet 60 Psi without PRV 60 Deg. C supply Up feed Water System

Source Pmin Pmax Temp Water method Booster Pump-1 Booster Pump-2 RP-01

6.

Triplex VFD driven pump in basement-1 for Cold water Supply Triplex VFD driven pump in basement-1 for Hot water Supply Hot water recirculation pumps.

Piping Material Here under are the recommended piping materials for the project. Pipe Description Type High level Cold water supply, hot Composite PPR PN 20 with PN-25 fitting. water supply, kitchen water, CPVC sch. 80 (only for Exposed piping ) Flushing Underground Water Supply HDPE PN 16

7.

Drainage System Double stack system comprising of separate Gray and Black water pipes with properly vented fixtures shall be adopted for building drainage. All Labs shall have a dedicated Waste pipe which will only be used to collect Lab drainage. Keeping in mind different PH values drained into the lab sinks, Polypropylene (PP) pipe shall be used. All lab drains stacks shall be connected to Acid Waste neutralization Pit which will eventually be connected to Hospital Sewage system. The neutralization pit shall be constructed of S.Steel or other acid resistant material and shall be filled with lime stone or Marble Chip. The Neutralization tank shall be sized for the dwell time of 2-3 hours as per ASPE guidelines. All labs sink shall be properly vented with dedicated vent piping. Traps for Eye wash shall either be provided with Seal trap primer or shall be connected with nearest lab sink drainage to prevent them from drying out.

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Mechanical Systems Design Criteria

C.

FIRE FIGHTING 1.

Codes and Standards The Fire fighting system for Labs shall be designed to comply with the following codes. i. Standards of National Fire Protection Association for Sprinkler system, NFPA-13 ii. Standards of National Fire Protection Association for Standpipe and Hose System, NFPA-14 iii. Codes for installation of Fire Water Pumps, NFPA-20. iv. NFPA-99 standard for healthcare facilities.

2.

Incoming Connections. As confirmed by AKU, fire water for WCH building shall be tapped form external AKU fire network. Since the incoming pressure is only 50 Psi which is NOT enough to accommodate the building needs, a Fire booster set shall be proposed in the basement plant room.

3.

Fire System for Labs. The following system shall be considered for the buildings. (a) (b) (c) (d)

Fire Sprinkler System Standpipe and Hose System Portable fire extinguishers Clean Agent fire suppression system in UPS room and IT Room

Labs shall be provided with Quick response, Canceled type Sprinklers designed as per Ordinary hazard Classification. In addition to sprinklers Class III stand pipe system shall also be provided throughout the facility as maximum travelling of 30 meters. A minimum of two Fire hose reels shall be provided on every floor. As per NFPA-99 Section 11-5, portable fire extinguishers shall also be provided in all labs including Storage areas. Fire will be provided in mechanical, Telecom and small electrical rooms and in lower compartment of Fire hose cabinets. 4.

Fire Piping Material. All Fire piping shall be seamless black steel schedule 40 as per ASTM A53.

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Mechanical Systems Design Criteria

D.

Piped Gas services 1.

Codes and Standards The Medical Gas system for Labs shall be designed to comply with the following codes. i. NFPA-99 standard for healthcare facilities. ii. HTM Guidelines

2.

Medical Gas system for Labs The following medical Gas systems shall be considered for labs based on the input received from Lab End user. 

Medical Oxygen



Medical Compressed Air System



Medical Vacuum System



CO2 Gas System



NO Gas system



N2 Gas system

Medical oxygen shall be tapped from hospital Central oxygen supply network while Medical Air and Medical Vacuum shall be generated on site by Medical grade Air compressors and Medical Vacuum Pumps. Both Medical Compressors and Medical Vacuum Pump shall be located in MEP plant room at roof level. Medical Compressor and Vacuum shall comply NFPA99. Medical Gas shall be provided in Ultrasound rooms, Recovery Rooms be as per HTM manual and NFPA-99. Medical Gas requirements for Labs shall be provided as per end user requirements. NO, N2 and CO2 gas shall only be considered for Labs as indicated by lab end user. NO, N2 and Co2 shall be provided through gas cylinders manifolds located in MEP on the roof in dedicated 2 hour fire rated compartments. 3.

Medical Gas Piping material and sizing: Medical gas piping shall be Type "K" Phosphorous Deoxidized, Non Arsenical, washed and degreased, seamless copper tubing as per BS EN 13348 with end free Capillary fittings as per BS EN 1254-1 with wrought copper, brass or bronze fittings designed expressly for brazed silver solder connections. All medical gas pipeline design shall be based on 5% Pressure drop from source of supply to the terminal unit at the specified flows.

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