Thesis Report - Complete[1]

Chapter 1: Introduction 1.1 Research Introduction Climate change is the change in global weather patterns such as average temperature, precipitation, day of sunlight and wind patterns. It involves change in the variability or average state of the atmosphere over a very long period. The factors which cause the climate change to occur are the effects of human activity, the variations in solar radiation, greenhouse effect and the earth’s orbit. The main factor which contributes to climate change is human activity. The human activity is beyond reasonable doubt lead to current rapid change in the world’s climate. The biggest factor of the recently concern is the increasing of CO2 level due to emissions from fuel combustion in automotive field, aerosols which exert a cooling effect, and cement manufacture. The rapid development of generation, also cause a lot of forests are destroyed for new development purpose. Consequently, the unbalance ecosystem will lead to climate change rapidly. One of the significant effects is greenhouse effect. Greenhouse effect means the change in the concentration of the gases such as water, vapor, CO2, CH4, N2O, and CFCs which trap infrared radiation from the Earth’s surface. The average temperature of the world indirectly also will increase due to greenhouse effect. Library is a collection of information, sources, resources and services. Library is also called collection of books in more traditional sense. In university, the library becomes the important place for students to search for information and studying. Therefore, the indoor environment quality (IEQ) plays an important role 1

for health and comfort of library. The IEQ includes temperature, relative humidity, concentration of CO2, concentration of CO, microbial contaminants, moisture, air velocity, noise from outside, vibrations, visual or lighting quality and etc. In fact, indoor air is often a greater health hazard than the corresponding outdoor condition. This is because indoor is a close surface system, the unhealthy conditions will trap in the close surface system and lead to health problem. From the occupant point of view, the idea situation of the indoor environment should satisfy all occupants and does not unnecessarily increase the risk or severity of illness or injury. (Hazim B. Awbi, 2008) HVAC system installed is to create or maintain the cooling and comfort in the libraries. However, due to the climate change recently, the increasing of outdoor temperature causing more heat to be transfer into the indoor of the building. Hence, the HVAC system needs to provide more cooling capacity to absorb the heat from outdoor. The buildings normally have to survive for at least 50 years, the HVAC system normally will design base on the climate during that time, so, sustainability of the HVAC system to provide the acceptable cooling and comfort level becomes a main concern in this thesis. Two libraries had been chosen in the tropical climate for my research work. They are Law faculty library and Engineering faculty library in University of Malaya. Both libraries are chosen for my research work is because they are built at different period of year. The air conditioner system of Law faculty library was installed during year 1997 while the air conditioner system of Engineering faculty library was installed during year 1985. This indicates that the air conditioner systems 2

installed in both of the libraries were in different of time based on the climate at that moment. Therefore, a comparison of the both of the air conditioner systems can be implemented to monitor the effect of the climate change to the design of the air conditioner systems in both of the libraries. To have more accuracy of prediction of trend of temperature and relative humidity inside both of the libraries in future, the actual current indoor environment quality was carried out. Few parameters were measured such as temperature, relative humidity, the concentration of carbon dioxide (CO2), the concentration of carbon monoxide (CO), air flow rate and particle count. Besides, the Transient System Simulation Program (TRNSYS) is used to predict the trend of temperature and relative humidity in both of the libraries based on the climate change in the tropical climate. Before that, the new weather profile need to generate based on the latest climate profile. By using TRNSYS program, analyzing of the both air conditioner systems can be carried out.

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1.2 Research Objective •

To investigate the effect on the HVAC system taken into account of climate change implication for the building and their technical services in tropical climates.

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To analyze the current situation of HVAC systems of Law faculty library and Engineering faculty library.

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To carry out empirical studies of Indoor Environment Quality (IEQ) of Law faculty library and engineering faculty library.

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To compare the trend of temperature and relative humidity of current situation and future prediction.

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To use Transient System Simulation Program (TRNSYS) to simulate the HVAC systems using the weather profile created base on climate change running at full load, 75% full load and half load.

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Chapter 2: Background and Literature Review 2.1 Heat Transfer by conduction and radiation To more understand about the how the climate change influence the performance of HVAC system and indoor environment quality, the effect of heat transfer, conduction, radiation, sensible heat and latent heat need to take in consideration. Of course, when the temperature outdoor is higher compare to indoor, the heat will transfer from outdoor to indoor. There are two ways of heat transfer can be occur, conduction and radiation through the wall and window of the buildings. The heat can transfer from outdoor into indoor through the wall by conduction. However, the major heat will transfer from outdoor into indoor through the window by conduction and also radiation. If the unshaded windows are exposed to the solar radiation, about 8 percent of the radiant energy is typically reflected back outdoors, from 5 to 50 percent is absorbed within the glass, the percentage of heat absorbed is depend on the composition and the thickness of the glass. The remainder is transmitted directly into indoor; it will become part of the cooling load. Incoming solar radiation --100%

Reflect radiation --8% Outward flow of absorbed radiation –8% Total solar heat excluded --16%

Inward Flow of absorbed radiation –4%

Transmitted solar radiation --80%

Total solar heat admitted --84% 5

Figure 2-1: Distribution of solar radiation falling on the clear plate glass The solar heat gain is the sum of the transmitted radiation and the portion of the absorbed radiation that flows inward. Moreover, heat also transfer through the glass by conduction whenever there is an outdoor-indoor temperature difference, so, the total rate of heat admission is: Total heat admission through glass = Radiation transmitted through glass + Inward flow of absorbed solar radiation + Conduction heat gain (Face C. McQuiston, 2004)

2.2 Sensible Heat and Latent Heat Besides, the indoor environment quality not only depends on the conduction and radiation from the outdoor, the sensible heat and latent heat also contribute to the cooling load. All matter typically exists in one of the three states: it is a solid, a liquid or a gas. Sensible heat means heat that changes the temperature of a substance without changing the substance’s state. It can be measured simply using thermometer. The unit of the sensible heat is Btus per hour (Btu/hr).

Latent heat or hidden heat is the heat required to change the state of a substance at the temperature. Latent heat needs to add to change the material from solid phase to liquid phase or from liquid phase to gas phase. On the other hands, the latent need to remove for changing phase of material from gas phase to liquid phase or from liquid phase to solid phase. The changing of water between its three phases requires the addition or removal of latent and sensible heat. The heart of the HVAC 6

system controls the latent and sensible heat. For example, 144 Btu of latent heat is taken to convert one pound of ice at 32˚F to one pound of water at 32˚F or vice versa. This type of heat is called latent heat of fusion. Another example, 180 Btu of sensible heat is taken to raise the temperature from 32˚F to 212˚F of one pound of the water. The exchange heat, either sensible heat or latent heat, is the basis for most heating and air-conditioning processes. In these HVAC processes, heat is added or removed from a medium such as water or air at a central point and then distribute this heated or cooled medium to all parts of the structure where it will be used to warm or cool the space. (Alan J. Zajac, 1997)

2.3 Ventilation system Moreover, the ventilation system also plays an important role to maintain the indoor environment in a good condition. According to the Oxford Dictionary, ventilation is to ‘expose to fresh air’ and to ‘cause air to circulate freely in an enclosed space’. The main purpose of the ventilation system is to provide the untainted air for occupants in indoor environment. The volume of air necessary to provide for human may be considered in following principal headings: •

Provision of oxygen for respiration

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Removal of products of exhalation

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Removal of body odor

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Removal of unwanted heat

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•

Removal of unwanted moisture and contaminants.

At the rest condition, the normal adult inhales between 0.20 and 0.12 liter/s of air and of this only about some 5% is absorbed as oxygen by the lungs. After that, the exhaled breath contains about 3% to 4% of CO2 which equal to about 0.004 liter/s. The concentration of CO2 at an indoor environment with accepted level is 500ppm or 0.5% by volume for an exposure of 8 hours. A good ventilation system can remove the odors arising from human occupation which the problem normally becomes serious only in crowded places. The unwanted heat means the sensible heat. The unwanted heat needs to remove so that the comfort temperature can be maintained. Ventilation system also used to remove the unwanted moisture in indoor environment. For example, if the moisture is high in libraries, it will give the impact to the books in libraries. The contaminants in indoor environment arising from tobacco smoke. However, the libraries do not face this type of problem because libraries are non smoking area. (P. L. Martin, 1995)

2.4 Heat Balance Method The concept of a design cooling load derives from the need to determine an HVAC system size that, under extreme conditions, with provide some specified condition within a space. The space served by an HVAC system commanly is referred to as a thermal zone or just a zone. Usually, the indoor boundary condition associated with a cooling load calculation is a constant interior dry-buld temperuture, but it could be a complex function, such as a thermal comfort condition. Generally, for an office it would be assumed to be a clear sunlit day with high outdoor wet-bulb and dry-bulb temperature, high office occupancy and a correspondingly high use of 8

equipmet and light. It is apparent that the boundary conditions for a cooling load determination are subjective. But, after the design boundary conditions are agreed upon, and then the design cooling load represents the maximum or peak heat extraction rate under those boundary conditions.

Convection to outside air Absorbeb incident solar

Outside face heat balance Through the wall conduction

Radiation from light Transmitted solar

Infiltration Ventilation Exhaust air

Inside face heat balance Convection to zone air

Air heat balance

Radiation

Radiation from internal sources Radiation exchange with other surfaces

Convection from internal source

HVAC system Figure2-2: The schematic heat balance model.

A complete, detailed model of all of the heat transfer processes occurring in a building would be very complex and would be impractical as a computational model 9

even today. However, there is fairly good agreement among building physics researchers and practitioners that certain modeling simplifications are reasonable and appropriate under a broad range of situations. Therefore, the simple model becomes the basis for most discussions of the heat transfer. The resulting formulation is called Heat Balance (HB) method. The processes that make up the heat balance model can be visualized using the schematic shown in figure 2-2. It consists of four distinct processes. They are: 1.

The outside face heat balance,

2.

The wall conduction process,

3.

The inside face heat balance,

4.

The air heat balance.

2.5 Radiant Time Series (RTS) method The radiant time series (RTS) method is a new method for performing design cooling load calculations. It is derived directly from the heat balance method, and effectively replaces all other simplified (non-heat-balance) methods such as the transfer function method, the cooling load temperature difference/solar cooling load/cooling load factor method, and the total equivalent temperature difference/time averaging method. RTS was developed in response to TC 4.1’s desire to offer a method that was rigorous, yet did not require iterative calculations of the previous method. In addition, for pedagogical reasons, it is desirable for the user to be able to

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inspect and compare the coefficients for different zone types. (Curtis O. Pedersen et al, 1998).

2.6 Fan Coil Unit A fan coil unit (FCU) is a simple device consisting of a heating or cooling coil and fan. It is part of an HVAC system found in residential, commercial, and industrial buildings. Since it does not have any duck work, a fan coil unit is used to control the temperature only in the space where it is installed. It is controlled either by a manual on/off switch or by thermostat. Due to their simplicity, fan coil units are more economic to install than ducted or central heating systems. However, they can be noisy because its fan is within the same space.

(Source: Internet Reference, (13/1/2009a))

Figure 2-3: Fan Coil Unit

The coil receives hot or cold water from a central plant, and removes or adds heat from the air through heat transfer. Fan coil units can contain their own internal thermostat, or can be wired to operate with a remote thermostat. Fan coil units circulate hot or cold water through a coil in order to condition a space. The unit gets its hot or cold water from a central plant, or mechanical room containing equipment for removing heat from the central building's closed-loop. The 11

equipment used can consist of machines used to remove heat such as a chiller or a cooling tower and equipment for adding heat to the building's water such as a boiler or a commercial water heater.

(Source: Internet Reference, (30/3/2009))

Figure 2-4: Fan coil unit layout

Fan coil units are divided into two types: two pipe fan coil units or four pipes fan coil units. Two pipe fan coil units have one supply and one return pipe. The supply pipe supplies either cold or hot water to the unit depending on the time of year. Four pipe fan coil units have two supply pipes and two return pipes. This allows either hot or cold water to enter the unit at any given time. In high-rise residential construction, typically each fan coil unit requires a rectangular through-penetration in the concrete slab on top of which it sits. Usually, there are either 3 or 5 copper pipes that go through the floor. The pipes are usually insulated with refrigeration insulation, such as acrylonitrile butadiene/polyvinyl chloride (AB/PVC) flexible foam (Rubatex or Armaflex brands) on all pipes or at least the cool lines. (Internet Reference, 12/1/2009).

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2.7 Air Handling Unit 2.7.1 Definition Air Handling Units are often called AHU. The air-handling unit is box-like equipment with a fan and a cooling coil inside. Some units also contain air filters. The whole fan and motor assembly, comprising shaft, bearings, pulley, and belting are usually put inside the AHU.

Source: Internet Reference, (13/1/2009b)

Figure 2-5: Air Handling Unit The basic function of the AHU is to suck air from the rooms, let it pass through chilled water cooling coils and then discharging the cooled air back to the rooms. Normally, letting it pass through panel or bag filters also filters the air. A certain amount of fresh air may be introduced at the suction duct so that air in the rooms may be gradually replaced. AHU's come in many sizes and shapes. Usually, the air conditioning designer will choose a particular AHU based on the air flow requirements and the cooling capacity. If humidity of the air has to be controlled, steam coils, or other heating coils may be installed. If the air has to be very cleaned, special HEPA filters have to be installed at the ducting outlets or at the AHU filter 13

box. Moisture in the air is condensed out when it comes into contact with the chilled water coils. At the bottom of the AHU, a pipe is installed so that water that is collected can be drained out. The fan and motor assembly is usually mounted on vibration dampers that absorb any vibrations generated. Removable panels are installed so that personnel can enter into the AHU for maintenance. Maintenance is mostly changing or washing of air filters, greasing of bearings, changing of belts, and general inspection and cleaning work. 2.7.2 Temperature Control Controlling the flow of chilled water through the cooling coils alters the temperature of the discharged air into the rooms. Control valves are used to throttle chilled water through the chilled water coils. A simple temperature control system uses thermostats to control on-off solenoid valves. A better control system uses temperature sensors, controllers, and motorized control valve. More complicating systems may have motor speed control for the fan. 2.7.3 Humidity Control Some critical processes may require that the humidity of the air-conditioned space be controlled. During the normal cooling process, as the air becomes cooler, the relative humidity of the air tends to increase. If the relative humidity have to be brought down, the air have to be heated by steam coils or other means. Steam coils, if installed will have their own controls. A typical control system has a temperature

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sensor, controller, and control valve. Usually, humans monitor the relative humidity, and the steam controller settings are adjusted accordingly. (Internet Reference, 2/12/2008).

2.8 Weather Data The weather data of Kuala Lumpur for 20 years periods were provided by Malaysian Meteorological Department. The weather data provided was used to generate TMY2 weather profile file which can used to predict the future trends of the weather profile. The generation and assessment of building simulation weather files was did by (Mark F. Jentsch et al.) in United Kingdom. In their research, they stated that current industry standard weather files for building simulation are not suited to the assessment of the potential impacts of a changing climate. This research describes the integration of future UK climate scenarios into the widely used Typical Meteorological Year (TMY2) and EnergyPlus/ESP-r Weather (EPW) file formats and demonstrates the importance of climate change analysis through a case study example. (Mark F. Jentsch et al. 2008). Besides, from Lisa Guan research study, she also stated that in order to study the impact of climate change on the building environment, the provision of suitable weather data become critical. She presented an effective framework and procedure to generate future hourly weather data. It is shown that this method is not only able to deal with different levels of available information regarding the climate change, but also can retain the key characters of a ‘‘typical’’ year weather data for a desired period. (Lisa Guan, 2008).

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Chapter 3: Methodology 3.1 Literature review •

The related books, journal papers, thesis about my thesis topic are searched and studied to have a clear understanding of my thesis scopes, background and objectives.

3.2 Fieldwork study planning •

Before carry out the effective fieldwork study at Law faculty library and Engineering faculty library, good strategies need to plan.

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The existing HVAC systems and floor areas were studied from mechanical and electrical (M&E) drawing; related data and suitable instruments were identified and prepared.

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Manual of instruments were read and demonstration of the instruments was made by the supervisor.

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Data tables were created to record the data.

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3.3 Fieldwork study

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Firstly, divide the floor plan of the libraries into smaller zone to increase the accuracy of the measurements.

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The indoor environment qualities (IEQ) were measured such as dry bulb temperature, wet bulb temperature, relative humidity, CO2 concentration, CO concentration, air velocity and air volume flow rate at each single zones.

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The IAQ monitor was used to measure dry bulb temperature, wet bulb temperature, relative humidity, CO2 concentration and CO concentration.

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The air velocity was measured by using air velocity meter.

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The probe of IAQ monitor was placed around 1.2 meter from the ground. Wait few minutes for the reading to be stabilized.

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The same procedures were applied to air velocity meter for air velocity measurement.

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Balometer was used to measure the air volume flow rate at each diffuser in both of the libraries.

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The outdoor conditions such as dry bulb temperature, relative humidity also were measured.

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The specifications of HVAC system were recorded for analyzing and simulating purpose.

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Data Logger was installed to record the continuous changing in dry bulb temperature and relative humidity of both of the libraries for one week.

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3.4 Data analyzing •

From the data recorded, the data are key in into proper tables in the computer for the ease of analyzing work.

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Heat load of each library was calculated by using heat load calculation form provided in Carrier Handbook.

3.5 Simulation •

TRNSYS simulation is used to simulate the HVAC systems of both of the libraries and to predict the sustainability of the HVAC system for 20 years downward by using the latest weather profile.

3.6 Comparison •

After analyze the data, the results obtain need to compare with the standard value which provided in the ASHERE handbook.

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3.7 Instrumentation Description 3.7.1 IAQ Monitor (KANOMAX-model 2211)  This equipment is used to measure the concentration of CO 2 and CO,

relative humidity, absolute humidity and dew point, wet bulb temperature.

Figure 3-1: IAQ Monitor (KANOMAX-model 2211) 3.7.2 Air Velocity Meter (TSI-model 8345)  This meter is used to measure on the air velocity, temperature and also flow rate. To measure for air velocity, the sensor needs to hold perpendicular to the air flow direction.

Figure 3-2: Air Velocity Meter (TSI-model 8345)

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3.7.3 Balometer (Models EBT720/EBT721)  This equipment is used to measure pressure, temperature, relative humidity, air velocity and air flow rate.

Figure 3-3: Balometer (Models EBT720/EBT721) 3.7.4 Data Logger  It is used to log the temperature and relative humidity for certain area for a long period.

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Figure 3-4: Data Logger

3.7.5 Transient System Simulation Program (TRNSYS)  The TRNSYS was used to simulate the HVAC systems.

Chapter 4: Field Work Study 4.1 Overview of the Existing Air-Conditioning System in Law Faculty Library 4.1.1 Introduction The Law faculty library is currently using water cooled air conditioning system (WCP). The WCP consists of Air Handling Unit (AHU), pumps and cooling tower. There are total 4 floors in Law faculty library. Each floor consists of 2 units of Air Handling Units (AHU) at 2 end of the Floor. All of the AHU are connected to a cooling tower. There are also 3 pumps to pump and circulate the cooling water between AHU and cooling tower. Basically, the system has 3 loops of circles, such as air loop, refrigerant loop and cooling water loop. Firstly, for the air loop, the air is drawn back from the indoor of the library to AHU room, then the air is mixed with the fresh air which drawn in form outdoor. After air mixing, the mixing air will pass through the filter and cooling coils in the AHU. The cooling and dehumidification process will take place here.

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After cooling and dehumidification process, the air will blow into indoor of the building by a fan. The second loop is refrigerant loop. The function of refrigerant loop is to absorb the heat in the air which passes through the cooling coil. There are 4 units of compressor inside each AHU to compress the evaporate refrigerant. Thirdly, the air conditioning system needs another loop called cooling water loop to transfer the heat from the refrigerant to ambient. Cooling water loop needs pumps to circulate the water from AHU to Cooling tower and heat is transferred to the ambient at cooling tower.

Cooling water Loop

Space

AHU

Cooling Tower

Air Loop Refrigerant Loop

Figure 4-1: Water Cooled Package Air Conditioning system diagram. 4.1.1.1 AHU Specifications AHU 1 Floor

Model

AHU 2 Cooling Capacity (Btu/hr)

Model

Cooling Capacity (Btu/hr)

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Ground Floor

Dunham-Bush WCP510

510000

Dunham-Bush WCP510

510000

First Floor

Dunham-Bush WCP510

510000

Dunham-Bush WCP365

365000

Second Floor

Dunham-Bush WCP435

435000

Dunham-Bush WCP435

435000

Third Floor

Dunham-Bush WCP580

580000

Dunham-Bush WCP435

510000

Table 4-1: The models and cooling capacities of AHUs for each floor.

Figure 4-2: Top view of cooling tower

Figure 4-3: Side view of cooling tower

Figure 4-4: Pumps

Figure 4-5: AHU

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Figure 4-6: Off-grill

Figure 4-7: Data measuring

4.1.2 Result and Analyzing 4.1.2.1 Ground Floor Results

Figure 4-8: Graph of Temperature and relative humidity of ground floor compare to comfort temperature and recommended relative humidity.

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Figure 4-9: Graph of CO2 concentration of ground floor compare to maximum limit of CO2 concentration.

Parameter

Reading

Maximum Temperature (˚C) 23.8 Minimum Temperature (˚C) 21.1 Average Temperature (˚C) 22.2 Maximum RH (%) 72.7 Minimum RH (%) 58.0 Average RH (%) 68.0 Maximum CO2 (ppm) 597 Minimum CO2 (ppm) 374 Average CO2 (ppm) 464 Maximum air flow (m/s) 0.24 Minimum air flow (m/s) 0.04 Aver air flow (m/s) 0.15 Table 4-2: Results summary for ground floor. 4.1.2.2 Discussion From the results obtained, the temperature average temperature at the ground floor of the Law faculty library is 22.2˚C. Beside the range of the temperature at this floor is lower than the comfort temperature. The range of temperature is between 21.1˚C and 23.8˚C. The occupants who stay at this floor will feel cool.

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Next, the average of the relative humidity at the ground floor is 68% RH. The maximum relative humidity and minimum relative humidity at this floor are 58% RH and 72.7% RH respectively. According to ASHRAE Handbook, the recommendation range of relative humidity in the library is between 50% RH to 60%RH. Therefore, the relative humidity of this floor already exits the maximum range of relative humidity. The average concentration of CO2 at the ground floor of the Law faculty library is 464 parts per million (ppm). The range of the CO2 concentration at the ground floor is between 374 ppm and 597ppm. From WHO ISO 7730, the limit of the air movement is 0.25m/s. From the measurement conducted, the maximum air flow and minimum air flow are 0.24m/s and 0.04m/s respectively. The average of the air flow is 0.15m/s. The air flows at this floor are considered acceptable. 4.1.2.3 First Floor Results

Figure 4-10: Graph of Temperature and relative humidity of first floor compare to comfort temperature and recommended relative humidity.

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Figure 4-11: Graph of CO2 concentration of first floor compare to maximum limit of CO2 concentration.

Parameter Maximum Temperature (˚C) Minimum Temperature (˚C) Average Temperature (˚C) Maximum RH (%) Minimum RH (%) Average RH (%) Maximum CO2 (ppm) Minimum CO2 (ppm) Average CO2 (ppm) Maximum air flow (m/s) Minimum air flow (m/s) Aver air flow (m/s)

Reading 24.1 20.9 22.2 62.9 56.3 60.4 477 387 423 0.15 0.01 0.06

Table 4-3: Results summary for first floor. 4.1.2.4 Discussion From the results measured, the average temperature, 22.2˚C, which is lower than comfort temperature, 24˚C. Besides, the maximum temperature and the minimum temperature are 24.1˚C and 20.9 respectively. Therefore, the condition in the first floor of the Law faculty library is considered cool. The relative humidity range at this floor is between 56.3% RH to 62.9% RH. The average of relative humidity is 60.4% RH. The relative humidity at this floor is considered acceptable.

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The concentration of CO2 is at acceptable level because the average of CO2 concentration is 423 ppm and lower than maximum limit of CO 2 concentration level. The range of CO2 concentration at this floor also below the maximum limit of CO2 concentration level which between 387 ppm and 477 ppm. The range of the air flow is between 0.01m/s to 0.15m/s and its fall into an acceptable range. 4.1.2.5 Second Floor Results

Figure 4-12: Graph of Temperature and relative humidity of second floor compare to comfort temperature and recommended relative humidity.

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Figure 4-13: Graph of CO2 concentration of second floor compare to maximum limit of CO2 concentration.

Parameter Maximum Temperature (˚C) Minimum Temperature (˚C) Average Temperature (˚C) Maximum RH (%) Minimum RH (%) Average RH (%) Maximum CO2 (ppm) Minimum CO2 (ppm) Average CO2 (ppm) Maximum air flow (m/s) Minimum air flow (m/s) Average air flow (m/s) Table 4-3: Results summary for second floor.

Reading 26.2 20.4 22.1 65.3 55.1 61.3 495 360 398 0.17 0.01 0.08

4.1.2.6 Discussion At Second floor of the Law faculty library, the average temperature is 22.1˚C which is lower than the comfort temperature. From the graph 4-12, it shows from zone 52 to zone 59 have the temperature which higher than comfort temperature. This is because the zone 52 to zone 59 are near the window and the wall of the building, more heat is transfer into these areas and cause the temperature of these zones are higher than comfort temperature. However, these zones still lower the maximum limit of the temperature which will cause heat stress inside the building.. The maximum limit of the temperature is 28˚C.

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The range of the relative humidity in this floor is between 55.1% RH to 65.3% RH. From the calculation, 63% of zones are higher than the maximum acceptable range of the relative humidity. For concentration of the CO2, the maximum CO2 concentration and minimum CO2 concentration are 495 ppm and 360 ppm. All the CO 2 concentrations at every zones are lower than maximum limit of CO2 level inside a building. The average air flow at this floor is 0.08 m/s. the range of the air flow is between 0.01 m/s to 0.17 m/s. Therefore, it is fall into satisfaction range according to the WHO ISO 7730. 4.1.2.7 Third Floor Results

Figure 4-14: Graph of Temperature and relative humidity of third floor compare to comfort temperature and recommended relative humidity.

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Figure 4-15: Graph of CO2 concentration of third floor compare to maximum limit of CO2 concentration.

Parameter Maximum Temperature (˚C) Minimum Temperature (˚C) Average Temperature (˚C) Maximum RH (%) Minimum RH (%) Average RH (%) Maximum CO2 (ppm) Minimum CO2 (ppm) Average CO2 (ppm) Maximum air flow (m/s) Minimum air flow (m/s) Aver air flow (m/s) Table 4-4: Results summary for third floor.

Reading 26.2 21.5 24.8 75.8 60.8 71.2 471 304 340 0.22 0.01 0.08

4.1.2.8 Discussion The graph 4-14 shows that the maximum temperature and minimum temperature at 3rd floor of the Law faculty library are 21.5˚C and 26.2˚C respectively. It also shows that almost 85% of the zones temperatures are higher than the comfort temperature. The average of temperature is 24.8˚C. 85% of the zones temperatures are higher than comfort temperature because one of the AHU was under technical maintenance at the moment which the measurement was conducted. Besides, 3 rd floor is the highest floor in the building; the additional heat is transfer into the areas through the roof compare to other floors. Hence, 3rd floor of the Law faculty library will experience higher heat transfer form outdoor environment to indoor environment. 31

The average relative humidity of this floor is 71.2% RH. The range of the relative humidity is between 60.8% RH and 75.8% RH. The relative humidity of this floor is all out of the maximum recommendation relative humidity. The most significant impact of relative humidity to the indoor environment is fungal growth. There are a lot of valuable books and collections inside the library, the growth of the fungal will damage the valuable book and collection because fungal are growth faster at high relative humidity condition. The level of CO2 at this floor is acceptable due to the range of CO2 concentration obtained is between 304 ppm and 471 ppm. The average of the concentration of CO2 is 340 ppm. The air flow also satisfies the standard condition with the range of air flow obtained was between 0.01 m/s and 0.22 m/s. The average of air flow of this floor is 0.08 m/s. 4.1.3 Volume Flow Rate Analyzing Volume flow rate of air is the total volume of air blow into the indoor environment by the air handling unit (AHU) of air conditional system per unit time. In the Law faculty library, there are total 8 units of AHU provide the air flow into the indoor environment to certain areas by ducting system. 4.1.3.1 Methodology Diffuser volume flow rate measurement

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First, all the location of diffusers at each area in the Law faculty library were recognized and recorded into the floor plan.

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Then, volume flow rate of diffuser were measured by using balometer and the data obtained were save into the meter logger.

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Next, all the saving data were extracted to the computer.

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Finally, data obtained were organized into a proper form and analyzing is made through the results.

Inlet air flow measurement •

All the AHUs in the Law faculty library were identified and the cooling capacities of each AHU were recorded.

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Then, the air velocity of the inlet were measured and saved in the meter logger.

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Next, the areas of the air inlet of AHUs were measured with the measuring tapes.

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Finally, data were extracted into the computer and analyzing was made according to the results obtained.

4.1.3.2 Results

Total Air Flow Rate Measured (CFM) AHU cooling capacity (RT)

GF 17841 85

1F 16436 72.9

2F 12728 72.5

3F 17479 90.8 33

Rated Volume Flow Rate (CFM) Maximum Temp of Air Flow ( °C) Minimum Temp of Air Flow ( °C) Average Temp of Air Flow ( °C)

34000 22.1 16.4 18.7

29160 20.9 19.9 20.5

29000 22.3 20.1 21.4

36320 24.2 20.3 21.3

Table 4-5: Volume flow rate of diffusers. .

Floor

Air Inlet Width (ft)

Air Inlet Depth (ft)

Air Inlet Area (ft2)

Air Velocity (ft/Min)

Volume Flow Rate (CFM)

GF-a

2.30

7

32.20

432.44

13924.49

GF-b

2.30

7

32.20

425.25

13693.05

1F-a

2.30

7

32.20

420.56

13542.11

1F-b

3.16

7

22.12

404.38

8944.78

2F-a

3.16

7

22.12

475.50

10518.06

2F-b

3.16

7

22.12

498.13

11018.53

3F-a

2.30

7

32.20

448.56

14443.71

3F-b

2.30

7

32.20

366.75

11809.35

Table 4-6: Inlet air flow reading. .

Floor

Cooling Capacit y (RT)

Rated Volume Flow Rate (CFM)

Inlet Volume Flow Rate (CFM)

Off grill Volume Flow Rate (CFM)

Percentage of loss (In-out)/In (%)

GF

85

34000

27617.54

17841

35.40

1F

72.9

29160

22486.89

16436

26.91

2F

72.5

29000

21536.59

12728

40.90 34

3F

90.8

36320

26253.06

17479

33.42

Table 4-7: Percentage loss of volume flow rate.

4.1.3.3 Discussion From the table 4-7, it had shown percentage of losses of the volume flow rate. The percentage of the losses of ground floor, first floor, second floor and third floor were 35.40%, 26.91%, 40.90% and 33.42% respectively. From the measurement, the second floor had the highest losses of the volume flow rate compare to other floors. There are few factors causes the losses of the volume flow rate. Firstly, the losses of volume flow rate are due to the friction inside the ducting system. The higher the friction inside the ducting system, the higher the losses of volume flow rate. Secondly, the losses of volume flow rate are due to the leakage of the system. The leakage of the system causes the air flow can not deliver to the off-grill in the building. Finally, the pressure inside the building also will give impact to the losses of volume flow rate. 4.1.4 Data Logger

35

4.1.4.1 Results

Figure 4-17: Graph of Temperature and relative humidity of ground floor. (2) Figure 4-18: Graph of Temperature and relative humidity of first floor. (1) Figure 4-16: Graph of Temperature and relative humidity of ground floor. (1) Figure 4-19: Graph of Temperature and relative humidity of first floor. (2) Figure 4-20: Graph of Temperature and relative humidity of second floor. (1)

Figure 4-21: Graph of Temperature and relative humidity of second floor. (2)

36

Figure 4-22: Graph of Temperature and relative humidity of third floor. (1) Figure 4-23: Graph of Temperature and relative humidity of third floor. (2)

4.1.4.2 Results summary of Data Logger Max Min Aver Temp Temp Temp (˚C) (˚C) (˚C) GF-1 22.80 18.12 20.77 GF-2 23.17 20.32 21.77 1F-1 23.65 19.73 21.97 1F-2 23.44 19.19 21.84 2F-1 24.41 20.84 22.71 2F-2 23.94 20.03 22.10 3F-1 28.05 21.12 24.03 3F2 27.59 20.71 23.69 Table 4-8: Results summary of data logger. Floor

Max RH (%)

Min RH (%)

Aver RH (%)

83.60 84.10 76.00 83.80 73.70 81.10 84.10 88.70

65.90 67.30 57.40 60.20 56.50 62.20 67.30 71.80

72.11 73.05 64.48 71.52 63.52 70.45 76.81 80.55

4.1.4.3 Discussion The data loggers were put in the Law faculty library to monitor the change of temperature and relative humidity for 7 days. Each floor was installed 2 data loggers

37

to collect the continuously change of temperature and relative humidity of indoor environment. From table 4-8, the highest temperature that achieved for library was 28.05 ˚C at the third floor on Sunday evening. According to library operating time, Sunday evening was the closing time, so, the air conditioning system will shut down for that moment and cause the raising of the temperature of the library. Based on the maximum temperatures were obtained of each floor, the air conditioning system able to maintain the temperature of the library to achieve the comfort temperature. However, the average temperatures of the Law faculty library were lower than comfort temperature. Especially for ground floor, first floor and second floor, they were 2 ˚C to 4 ˚C lower than the comfort temperature. Therefore, the current situations of the library for these floors were considered cool. Mean that the cooling capacities which provide by air conditioning system were higher than the heat load needed. For relative humidity obtained for Law faculty library, the highest relative humidity can be achieved was 88.70% RH. The range of the maximum relative humidity was also very high, which were between 76% RH and 88.70% RH at library. According to the graphs above showed that the maximum relative normally achieved during 6 am to 7 am in the morning. This was because outdoor relative humidity was highest during that period. From the measurements, it clearly showed that the indoor relative humidity was strongly depend on the outdoor relative humidity.

38

Besides, the average relative humidity and the minimum relative humidity measured for library were considered high compare to the recommended relative humidity which was 50%RH to 55%RH for libraries. Malaysia is a hot and humid country, so, the relative humidity of the outdoor environment is always high. It will cause the high relative humidity at indoor environment when the fresh air is drawn in to the indoor space. Normally, the air conditioning system designs in tropical climate were based on the seasonal country weather data which is cool and dry. These were because no existing weather data in tropical climate for air conditioning system design purpose used in current commercial software. By the way, the dehumidification process always been ignored in air conditioning system design and cause high relative humidity at indoor environment.

39

4.2

Overview

of

the

Existing Air-Conditioning

System

in

Engineering Faculty Library 4.2.1 Introduction The Engineering Library is located at the sixth floor of the Block M Laboratory Wing at the Faculty of Engineering. In 1985, the Library was absorbed into the University of Malaya Library system. The library is opened from Monday to Friday and the operation hours are from 8.30 am until 5.30 pm. Engineering Library is using Fan Coil Unit (FCU) air conditioning system. There are seven units of condensers placing on top of the roof which are air cooled type. Above the ceiling of the library, there are three units of fan coil units which located above the Thesis Room, Discussion Room and Reference Room respectively. The system circulates the cool air from the FCU which transfers the heat through refrigerant as the cooling agent. The refrigerant will be pumped to the condenser and release the heat to the surrounding by the blowing of fan. The Specification of Condenser: Model MYSS 125B-FBAO S/No. MJGC3146 Compressor input 12900 W/27.6 A Refrigerant R22/7.6 kg Volt/Ph/Hz 380-415/3/50 Fan motor input 700 W/3.43 A 40

Crankcase Heater Control rating

70 W 220-240 v AC

Table 4-9: The specifications of condenser.

The specifications for the FCU are as follows:

FCU

FCU in Thesis Room

FCU in Discuss Room

FCU in Reference Room

YSB 200B 1772 200000 R22

YSB 250B 1553 250000 R22

YSB 300B 1376 300000 R22

2 X 5.8 kg 3 380-420 V/50 Hz 4000 W

2 X 7.8 kg 3 380-420 V/50 Hz 4000 W

3 X 5.8 kg 3 380-420 V/50 Hz 5500 W

8.4 A

8.4 A

11.3 A

Specification

Model Serial No. Cooling Btu/Hr Refrigerant Charge Phase Volt Watt Output: Amp

Table 4-10: The specifications of FCU.

4.2.2 Results of Engineering Faculty Library Figure 4-24: Graph of Temperature and relative humidity of engineering faculty library compare to comfort temperature and recommended relative humidity.

Figure 4-25: Graph of CO2 concentrations of engineering faculty library compare to maximum limit of CO2 concentration.

Parameter

Reading 41

Maximum Temperature (˚C) 26.20 Minimum Temperature (˚C) 23.20 Average Temperature (˚C) 25.18 Maximum RH (%) 56.60 Minimum RH (%) 49.00 Average RH (%) 52.25 Maximum CO2 (ppm) 621 Minimum CO2 (ppm) 395 Average CO2 (ppm) 467 Maximum air flow (m/s) 0.36 Minimum air flow (m/s) 0.02 Average air flow (m/s) 0.10 Table 4-11: Results summary of engineering faculty library.

4.2.3 Discussion Form the graph 4-11, 85% out of the zones in the Engineering faculty library are higher than the comfort temperature. The maximum temperature in the library can reach until 26.2˚C. The highest temperature is 26.2˚C was found at zone 43 while the lowest is 23.2˚C was found at zone 7. Zone 43 is located at reference room. The high temperature is caused by the solar heat gain through the window. Another factor contributed to this is the poor ventilation in that zone. From the zone 3 to zones 9, these areas are placed book stacks and books. The higher volume flow rates are put in to these areas and provide an acceptable cooling at these zones which the range of temperature is between 23.2˚C to 24˚C. For other zones such as study area, computer room, and rest corner, the average temperature obtained was around 25.18˚C which higher than comfort temperature. 42

The range of relative humidity of Engineering faculty library is between 49% RH and 56.60% RH. Compare the relative humidity measured to the recommendation range of relative humidity; the relative humidity of this library is in satisfaction range. Besides, the maximum of CO2 concentration and the minimum of CO2 concentration are 395 ppm and 671 ppm. Hence, the concentration of CO2 is lower than the maximum limit of the standard CO2 concentration, it can be considered as good indoor quality due to this aspect. Next, the air flow range is between 0.02 m/s to 0.36 m/s. the average air flow is 0.10 m/s, compare to recommendation air flow range, the results of air flow obtained form measurement are considered acceptable.

4.2.4 Volume Flow Rate Analyzing The same methodology which used in the Law faculty library are applied at the Engineering faculty library. Because of some technical problem, only the off-grill of the volume flow rate had been measured.

4.2.5 Results of the volume flow rate of the diffuser Total Volume Flow Rate Measured (CFM) AHU cooling capacity (RT) Rated Volume flow rate (CFM)

6902 62.5 2500

CFM RT

0

CFM 43

Table 4-11: Results of the volume flow rate of the diffusers.

4.2.6 Discussion The total volume flow rate measured of the Engineering faculty library was 6902 CFM only. If compare to the rated volume flow rate of the fan coil units (FCU) of the library, it only provided 27.61% of the rated volume. In this content, it means a lot of losses occur in the system. After investigations, the main losses due to the system were due to the leakage of the ducting system. Following were the photos shown of the leakage of ducting system.

Figure 4-26. The leakage ducts in the engineering faculty library.

4.2.7 Data Logger

44

Figure 4-27: Graph of temperature and relative humidity of engineering faculty library. (1)

Figure 4-28: Graph of temperature and relative humidity of engineering faculty library. (2)

4.2.8 Results summary of Engineering faculty library

Location 1 2

Max Temp (˚C) 31.30 31.74

Min Temp (˚C) 24.26 20.41

Aver Temp (˚C) 27.51 26.80

Max RH (%)

Min RH (%)

Aver RH (%)

78.30 74.40

45.00 50.40

62.46 57.09

Table 4-12: Results summary of engineering faculty library.

45

4.2.9 Discussion There was two data loggers installed in Engineering faculty library to monitor the indoor temperature and relative humidity. One of the data loggers was installed at the study space of the occupants and the second data logger was installed near the book stack of the library. According to table 4-12, the average temperatures of Engineering faculty library were higher than comfort temperature which were 27.51 ˚C and 26.80 ˚C. It means that the current system already can not provide the comfort temperature to the indoor space. Maximum temperature had reached until 31.74 ˚C at Sunday evening because the air conditioning system of library was shut down during weekend, therefore the indoor temperature will raised up to the highest temperature. From the minimum temperature, second data loggers had lower minimum temperature compare to the first data logger. This was because higher volume flow rates were provided to the book stack area. For relative humidity measurement, the average relative humidity were 62.46% RH and 57.09% RH which still in acceptable range. From the graph 4-27and graph 4-28, it showed that the relative humidity were higher during night time because higher relative humidity at outdoor environment.

4.3 Chapter Summary

46

From the measurement, the temperature of Law faculty library was around 22˚C and was considered cool. The relative humidity was high in library which was around 57.4% RH to 88.7% RH. The CO2 concentration, CO concentration and air flow were in good conditions. For Engineering faculty library, the temperature was higher than comfort temperature which was around 24.26˚C to 31.30˚C. The relative humidity, CO2 concentration, CO concentration and air flow were in good conditions.

Chapter 5: Heat Load Calculation 5.1 Introduction Heat load calculation is a method to determine the cooling capacity of the air conditioning system. It is determined by including the heat transfer into the building through the walls, the windows and the roof of the building. Besides, it also includes the sensible load and latent load inside the building. The sensible load includes the sensible heat generated by the occupants, the equipments, the lighting, infiltration and ventilation. The latent load involves the latent head generated form occupants, infiltration and ventilation.

5.2 Formula used for the heat load calculation

•

Heat gain from window

47



Solar:

Where Q

= Head gain, (Btu/hr)

A

= Area, (

SHGF = Peak solar heat gain through ordinary glass, (Btu/hr.



SC

= Shading coefficient, (dimensionless)

CLF

= Cooling load factor, (dimensionless)

)

Conductive:

Where Q

= Heat gain, (Btu/hr)

A

= Area, (

U

= Transmission coefficient, (Btu/hr.

) .˚F)

CLTD corrected = cooling load temperature difference, (˚F)

48

•

Heat gain for solar and trans gain from wall & roof

Where Q

= Heat gain, (Btu/hr)

A

= Area, (

U

= Transmission coefficient, (Btu/hr.

) .˚F)

CLTD corrected = Equivalence temperature different, (˚F)

•

Heat gain due to occupancy

Where Q

= Heat gain, (Btu/hr)

n

= Number of occupant, (dimensionless)

Qs

= Sensible heat gain of occupant, (Btu/hr)

Ql

= Latent heat gain of occupant, (Btu/hr)

Library is categorized in low degree activity group therefore it is more on seated and very light work.

49

•

Heat gain due to lighting

Where Q

= Heat gain from lighting

W

= Total lamp Wattage

BF

= ballast factor

N

= Total number of lamps

For florescent lamps, W= 36 watts

•

Heat gain due to equipment

Electricity equipments are the other sources of heat generated in air conditioned space. Heat generated due to the less efficiency of the electricity equipment especially in office, hospital, and library. Thus, the heat load due to equipments can be calculated by using ASHRAE tables and standards 1997-28. •

Cooling load due to ventilation

To control the comfort level, it is necessary to control the rate and location of ventilation air entering the building. It can be accomplished through forced ventilation where a fan provides a predictable and constant of outdoor air intake into the building.

50

Base on the table Outdoor Air Requirements for Ventilation (institution facilities): Application

Estimated Max Occupancy,

Outdoor Air Requirement CFM/person L/s.person

P/1000 Libraries

20

15

8

The sensible and latent cooling load can be calculated by using the following equation: =

1.08(CFM)(∆T)

=

4800(CFM)(∆W)

Where, = = BF = ∆T = ∆W =

Sensible heat Latent heat Ballast factor Temperature change Humidity ratio of air change

51

5.3 Calculation and Discussion 5.3.1 Heat Load Calculation of Law faculty library CONDITIONS OUTDOOR (OA)

DB 95 7

WB 84.2

%RH 70

GR./ LB 177

ROOM (RM)

3.4 2

62.6

55

66.5

DIFERRENCE 1.6 110.5 Table 5-1: Temperature difference calculations from peak outdoor conditions.

5.3.1.1 Heat Load Calculation for Ground Floor Sensible heat gain Conduction Surface-facing Roof Wall(N) Wall(E) Wall(S) Wall(W) Glass(N) Glass(E) Glass(S) Glass(W)

Area/Ft2 0 454.35 1155.84 1242.70 1190.93 1060.15 358.66 271.79 323.57

U 0 0.48 0.48 0.48 0.48 1.04 1.04 1.04 1.04

CLTD corrected 0 18.5 28.25 18.5 23.05 21.1 22.4 19.15 22.4

Btu/hr

Subtotal

0 4034.614 15673.17 11035.21 13176.44 23263.85 8355.261 5412.99 7537.79 88489.32 52

Solar Glass-Facing Glass(N) Glass(E) Glass(S) Glass(W)

Area/Ft2 1060.15 358.66 271.79 323.57

SHGF 39 231 44 231

SC 0.45 0.45 0.45 0.45

CLF Btu/hr 0.72 13396.01 0.29 10811.88 0.55 2959.804 0.3 10090.4 Subtotal 37258.09 Table 5-2: Heat load calculations for ground floor of the Law faculty library.

Internal sensible heat Item Occupants Electrical Appliances Lights Computer

Quantity 80

Btu/hr/person 230

Btu/hr 18400

1 W=3.4Btu/hr 3.4 3.4 subtotal

Btu/hr 61506 14875 94781

Quantity 402 10

Watt 36 350

Factor 1.25 1.25

Infiltration Item Door

Delta T 21.6

Constant 1.09

CFM 500

Btu/hr 11772

Ventilation Item Occupant

Quantity 80

CFM/person 18

CFM 1440

Btu/hr 33903.36 Sensible Subtotal 266203.8

Latent heat gain Source Occupants infiltration ventilation

Quantity 80

Btu/hr/person 190

Btu/hr 15200

Latent Subtotal

37570 108201.6 160971.6

Total

427175.4

CFM 500 1440

Table 5-2: Heat load calculations for ground floor of the Law faculty library. (continued)

53

5.3.1.2 Heat Load Calculation for First Floor Sensible heat gain Conduction Surface-facing

Area/Ft2

U

Roof Wall(N) Wall(E) Wall(S) Wall(W) Glass(N) Glass(E) Glass(S) Glass(W)

0 1007.73 1034.64 1017.95 1069.73 385.57 358.66 375.34 323.57

0 0.48 0.48 0.48 0.48 1.04 1.04 1.04 1.04

Solar Glass-Facing Glass(N) Glass(E) Glass(S) Glass(W)

Area/Ft2 385.57 358.66 375.34 323.57

SHGF 39 231 44 231

CLTD corrected 0 18.5 28.25 18.5 23.05 21.1 22.4 19.15 22.4

SC 0.45 0.45 0.45 0.45

Btu/hr

Subtotal

0 8948.60 14029.66 9039.41 11835.45 8460.87 8355.26 7475.28 7537.79 75682.33

CLF 0.72 0.29 0.55 0.3 Subtotal

Btu/hr 4872.02 10811.88 4087.46 10090.40 29861.76

Btu/hr/person 230

Btu/hr 18400

1 W=3.4Btu/hr 3.4 3.4 subtotal

Btu/hr 60894 17850 97144

Internal sensible heat Item Occupants Electrical Appliances Lights Computer Infiltration Item Door

Quantity 80 Quantity 398 12

Watt 36 350

Factor 1.25 1.25

Delta T 21.6

Constant 1.09

CFM 500

Btu/hr 11772

54

Ventilation Item Occupant

Quantity CFM/person 80 18

CFM 1440

Btu/hr 33903.36

Sensible Subtotal Table 5-3: Heat load calculations for first floor of the Law faculty library.

Source Occupants

Quantity 80

infiltration ventilation

Latent heat gain Btu/hr/person 190 CFM 500 1440 Latent Subtotal Total

248363.45

Btu/hr 15200 37570 108201.6 160971.6 409335.05

Table 5-3: Heat load calculations for first floor of the Law faculty library. (continued)

5.3.1.3 Heat Load Calculation for Second Floor Sensible heat gain Conduction Surface-facing Roof Wall(N) Wall(E) Wall(S) Wall(W) Glass(N) Glass(E) Glass(S) Glass(W) Solar Glass-Facing Glass(N) Glass(E) Glass(S) Glass(W)

Area/Ft2 0 1007.73 1034.64 1017.95 1069.73 385.57 358.66 375.34 323.57

Area/Ft2 385.57 358.66 375.34 323.57

U 0 0.48 0.48 0.48 0.48 1.04 1.04 1.04 1.04

SHGF 39 231 44 231

CLTD corrected 0 18.5 28.25 18.5 23.05 21.1 22.4 19.15 22.4

SC 0.45 0.45 0.45 0.45

Subtotal

Btu/hr 0.00 8948.60 14029.66 9039.41 11835.45 8460.87 8355.26 7475.28 7537.79 75682.33

CLF 0.72 0.29 0.55 0.3 Subtotal

Btu/hr 4872.02 10811.88 4087.46 10090.40 29861.76 55

Table 5-4: Heat load calculations for second floor of the Law faculty library.

Internal sensible heat Item Occupants Electrical Appliances Lights Computer

Quantity 80

Btu/hr/person 230

Btu/hr 18400.00

1 W=3.4Btu/hr 3.4 3.4 subtotal

Btu/hr 60282.00 14875.00 93557.00

Quantity 394 10

Watt 36 350

Factor 1.25 1.25

Infiltration Item Door

Delta T 21.6

Constant 1.09

CFM 500

Btu/hr 11772.00

Ventilation Item Occupant

Quantity 80

CFM/person 18

CFM 1440

Btu/hr 33903.36 Sensible Subtotal

244776.45

Btu/hr/person 190

Btu/hr 15200.00

Latent Subtotal

37570.00 108201.60 160971.60

Latent heat gain Source Occupants infiltration ventilation

Quantity 80 CFM 500 1440

Total

405748.05

Table 5-4: Heat load calculations for second floor of the Law faculty library. (continued)

56

5.3.1.4 Heat Load Calculation for Third Floor Sensible heat gain Conduction Surface-facing

Area/Ft2

U

Roof Wall(N) Wall(E) Wall(S) Wall(W) Glass(N) Glass(E) Glass(S) Glass(W)

1616.04 873.61 900.52 883.83 935.61 385.57 358.66 375.34 323.57

0.2 0.48 0.48 0.48 0.48 1.04 1.04 1.04 1.04

Solar Glass-Facing Glass(N) Glass(E) Glass(S) Glass(W)

Area/Ft2 385.57 358.66 375.34 323.57

SHGF 39 231 44 231

CLTD corrected 56.2 18.5 28.25 18.5 23.05 21.1 22.4 19.15 22.4

SC 0.45 0.45 0.45 0.45

Btu/hr

Subtotal

18164.29 7757.62 12211.00 7848.43 10351.55 8460.87 8355.26 7475.28 7537.79 69997.81

CLF 0.72 0.29 0.55 0.3 Subtotal

Btu/hr 4872.02 10811.88 4087.46 10090.40 29861.76

Btu/hr/person 230

Btu/hr 18400.00

1 W=3.4Btu/hr 3.4 3.4 subtotal

Btu/hr 61506.00 29750.00 109656.00

Internal sensible heat Item Occupants Electrical Appliances Lights Computer

Quantity 80 Quantity 402 20

Watt 36 350

Factor 1.25 1.25

Infiltration Item Door

Delta T 21.6

Constant 1.09

CFM 500

Btu/hr 11772.00

Ventilation Item Occupant

Quantity 80

CFM/person 18

CFM 1440

Btu/hr 33903.36 Sensible Subtotal

255190.93

Table 5-5: Heat load calculations for third floor of the Law faculty library. 57

Source Occupants

Quantity 80

infiltration ventilation

Latent heat gain Btu/hr/person 190 CFM 500 1440 Latent Subtotal Total

Btu/hr 15200.00 37570.00 108201.60 160971.60 416162.53

Table 5-5: Heat load calculations for third floor of the Law faculty library. (continued) 5.3.1.5 Result Summary of Heat Load calculation for Law Faculty library

Floor GF 1F 2F 3F

Total Heat Gain

Design Cooling

(Btu/hr)

Capacity (Btu/hr)

427175.38 409335.05 405748.05 416162.53

1020000 875000 870000 1090000

Volume flow rate per area (cfm/ft2) 58 50 50 62

Table 5-6: The results summary of total heat gains and design cooling capacities for Law faculty library.

5.3.1.6 Discussion From the table 5-6, the total heat gains of Law faculty library were 427175.38 Btu/hr, 409335.05 Btu/hr, 405748.05 Btu/hr and 416162.53 Btu/hr at ground floor, first floor, second floor and third floor respectively. Compare the results between each floor; the ground floor had the highest total heat gain among each floor in the Law faculty library. The reason was ground floor was the main entrance of the library; all the students and staffs were going in and out from library through the door at ground floor, so, high infiltration loss at the main entrance due to high

58

frequency of door opening. Therefore, this situation will increase the cooling load of the indoor environment because cool air was transfer out from the building. Secondly, the calculations also showed that the third floor of the library had higher total heat gain, which was 416162.53 Btu/hr compare to first floor and second floor of the library. This was because third floor is the top floor in Law faculty library, the extra heat gains of this floor are come from the roof of the library. Besides, there is management office and computer corner at this floor. Therefore, third floor consists of higher number of computers; it also contributed heat gain to the indoor environment. Thus, heat load of third floor was higher than first floor and second floor. Furthermore, the heat gain of first floor was 409335.05 Btu/hr and the heat gain of the second floor was 405748.05Btu/hr from the calculations. The total heat gain of first floor and second floor were lower than ground floor and third floor because they had no cooling loss for door infiltration and heat gain from roof top. There were also varies design cooling capacities were recorded. The cooling capacities recorded were 1020000 Btu/hr, 875000 Btu/hr, 870000 Btu/hr and 1090000 Btu/hr for ground floor, first floor, second floor and third floor respectively. Basically, the design cooling capacities of the Law faculty library were based on rule of thumbs calculations. Normally, the volume flow rate needed for indoor space per square feet is 50 cfm/ft2. From table 5-6, it showed the volume flow rate per square feet of the library were 58 cfm/ft2 , 50 cfm/ft2 , 50 cfm/ft2 , and 62 cfm/ft2 from ground floor to third floor. There were higher design cooling capacity at ground floor and third floor because of extra heat gain at these floors. 59

Compare the total heat gain to the design cooling capacities, the percentage of heat gain over the design cooling capacities of each floors were 41.88%, 46.78%, 46.63% and 38.83% for ground floor, first floor, second floor and third floor respectively. From the calculations above, it showed that the safety factor of cooling capacities design was two. Mean that the air conditioning system at the Law faculty library was oversize for 2 times larger. The purpose for over sizing the design cooling capacities was to maintain the comfort indoor environment in future. Due to the unexpected change of the climate and the additional internal and external heat gain, over sizing the air conditioner system was to make sure the recommended indoor quality are achieved. Besides, the decay of the performance and efficiency of the air conditioning system, it also became a consideration factor in designing the cooling capacities of the air conditioning system. Therefore, to have a clear picture of the trend of indoor quality profile and the sustainability of the air conditioning system in future, the TRNSYS simulation software was used to simulate the temperature and relative humidity profile of the indoor environment of library based on the latest climate weather profile. The TRNSYS simulation will discuss detail in the following chapter.

5.3.2 Heat Load Calculation for Engineering faculty library

60

Sensible heat gain Conduction Surfacefacing Roof Wall(N) Wall(E) Wall(S) Wall(W) Glass(N) Glass(E) Glass(S) Glass(W) Solar Glass-Facing Glass(N) Glass(E) Glass(S) Glass(W)

Area/Ft 11998 348.00 250.00 303.00 194.00 723.00 379.00 605.00 416.00

2

Area/Ft2 723.00 379.00 605.00 416.00

U 0.2 0.415 0.415 0.415 0.415 1.04 1.04 1.04 1.04

SHGF 39 231 44 231

CLTD corrected 56.2 18.5 28.25 18.5 23.05 21.1 22.4 19.15 22.4

SC 0.45 0.45 0.45 0.45

Subtotal

Btu/hr 134857.52 2671.77 2930.94 2326.28 1855.76 15865.51 8829.18 12049.18 9691.14 56219.76

CLF 0.72 0.29 0.55 0.3 Subtotal

Btu/hr 9135.83 11425.14 6588.45 12972.96 40122.38

Btu/hr/person 230

Btu/hr 23000.00

1 W=3.4Btu/hr 3.4 3.4 3.4 subtotal

Btu/hr 44982.00 22312.50 6600.25 90294.50

Internal sensible heat Item Occupants Electrical Appliances Lights Computer Photocopier

Quantity 100 Quantity 294 15 1

Watt 36 350 1553

Factor 1.25 1.25 1.25

Infiltration Item Door

Delta T 21.6

Constant 1.09

CFM 500

Btu/hr 11772.00

Ventilation Item Occupant

Quantity CFM/person 100 18

CFM 1800

Btu/hr 42379.20

Sensible Subtotal Table 5-7: Heat load calculations for the Engineering faculty library.

Source

Quantity

Latent heat gain Btu/hr/person

240787.84

Btu/hr 61

Occupants

100

190

19000.00

Latent Subtotal

75140.00 135252.00 229392.00

CFM 1000 1800

infiltration ventilation

Total 470179.84 Table 5-7: Heat load calculations for the Engineering faculty library. (continued) 5.3.2.1 Result Summary of Heat Load calculation for Law Faculty library

Location

Total Heat Gain

Design Cooling

(Btu/hr)

Capacity (Btu/hr)

470179.84

750,000

Volume flow rate per area (cfm/ft2)

Engineerin g faculty

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library Table 5-8: The result summary for the Engineering faculty library.

5.3.2.2 Discussion From the table 5-8, the total heat gain of the Engineering faculty library was 470179.84 Btu/hr. There were 3 FCU provided cooling capacities to the library. The design cooling capacities of the each FCU were 300000 Btu/hr, 250000 Btu/hr and 200000 Btu/hr respectively. Hence, total design cooling capacity was 750000 Btu/hr. Compare between the total heat gain of single floor at Law faculty library and the total heat gain of Engineering faculty library, it shown that the total heat gain of the Engineering faculty library is higher than the total heat gain of single floor at Law faculty library. This was because the fraction of window to the wall of Engineering faculty library is higher than the fraction of window to the wall of Law 62

faculty library. By this ways, more solar heat was transfer in the indoor environment of the Engineering faculty library. Therefore, the total heat gain of the Engineering faculty library is higher than the total heat gain of the Law faculty library. The percentage of the total heat gain over the design cooling capacity is 62.69%. For this study purpose, some assumptions need to make. First, performance of the air conditioning system was assumed to be constantly decayed through out the years. The efficiency of the air conditioning system also assumed as 100% efficiency. Hence, based on the calculations, the cooling load need was 62.69% of the total design cooling capacity, mean that as long as the decreasing of the performance of the air conditioning system do not more than 40% of the total design cooling capacity, the system still can provide the comfort indoor environment for the Engineering faculty library. However, the climate change of the outdoor environment gives a big impact to the indoor total heat gain. Besides, the change of the indoor environment also will affect the total heat gain. The following simulation chapter will discuss about the indoor environment in future taken into account of climate change impact.

5.4 Chapter summary

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From the heat load calculations for Law faculty library, the percentage of heat gain over the design cooling capacities of each floors were 41.88%, 46.78%, 46.63% and 38.83% for ground floor, first floor, second floor and third floor respectively. For Engineering faculty library, the percentage of heat gain over the design cooling capacities was 62.69%. Heat load calculation can not use to estimate and predict the future conditions of the libraries, it only used to compare between the heat load and the design cooling capacities.

Chapter 6: TRNSYS Simulation 64

6.1 Introduction to TRNSYS Simulation Studio TRNSYS (Transient System Simulation Program) is a complete and extensible simulation environment for the transient simulation of systems, including multi-zone buildings. Engineers and researchers around the world are using this program to validate new energy concepts, from simple domestic hot water systems to the design and simulation of buildings and their equipment, such as control strategies, occupant behavior, alternative energy systems (wind, solar, photovoltaic, hydrogen systems), etc. The modular structure and DLL-based architecture of TRNSYS allows users and third-party developers to easily add custom component models, using all common programming languages (C, C++, PASCAL, FORTRAN, etc.).

To create a TRNSYS project, it is typically setup by connecting modules graphically in the Simulation Studio. Each type of module is described by a mathematical model in the TRNSYS simulation engine and has a set of matching Proforma's in the Simulation Studio. The proforma has a black-box description which processes the inputs to produce outputs and passes the output to another module for further calculation.

6.2 Simulation of Weather for Tropical climate 65

6.2.1 Introduction Before looking into the indoor environment quality, the main concern is the trend of the ambient conditions. In this research, how the impact of the ambient conditions to the indoor environment quality become a very important aspect here. Therefore, the weather of the tropical climate was generated by using TRNSYS Simulation and the profile of the ambient temperature and the ambient relative humidity were shown in the figure below. The forecast of the weather were based on the weather data of Kuala Lumpur. Following graph are the ambient temperature and ambient relative humidity simulation for year 2000, year 2020 and year 2050.

Figure 6-1: Graph of ambient temperature and relative humidity at year 2000.

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Figure 6-2: Graph of ambient temperature and relative humidity at year 2020.

Figure 6-3: Graph of ambient temperature and relative humidity at year 2050.

6.2.2 Discussion 67

Year 2000 2020 2050

Max Temp, (˚C) 35.30 36.10 37.42

Min Temp, (˚C) 20.85 21.81 22.69

Aver Temp, (˚C) 27.16 28.13 29.22

Max RH (%) 100.00 99.00 99.00

Min RH, (%) 40.50 37.50 22.69

Aver RH, (%) 81.87 80.71 78.72

Table 6-1: Summary of outdoor conditions. From the table 6-1, it showed that the average temperature and average relative humidity were 27.16˚C and 81.87˚C during year 2000. Mean that the tropical climate is hot and humid. Besides, from the weather forecasting, the temperature will increase around 1˚C for next 20 years and the relative humidity will decrease around 1% to 2% for next 20 years. Therefore, the increasing of temperature and the decreasing of relative humidity in future from the weather forecasting will affect the current installed air conditioning system. The increasing temperature will be concern because it affect the determination of extra cooling capacity need to add to maintain the comfort environment in the building.

6.3 Simulation of Law Faculty Library

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6.3.1 Layout of TRNSYS model for Law faculty library

Weather data

Radiation Turn

Heat Gain Controller Sky temp

Psychrometrics

Law Library GF

Psychrometrics-2

Temperature Plotter

Psychrometrics-3

Air Change Controller Psychrometrics-4

Air Mixer

Cooling Coil

Psychrometrics-5

Fan

Air Mixer controller

Cooling Tower

Pump

WCP

Energy Transfer Plotter

Figure 6-4: Layout of TRNSYS model for ground floor.

Weather data

Radiation Turn

Heat Gain Controller Sky temp

Psychrometrics

Law Library 1F

Psychrometrics-2

Temperature Plotter

Psychrometrics-3

Weather data

Radiation

Air Mixer

TurnPsychrometrics-4

Cooling Coil

Air Change Controller Psychrometrics-5

Fan Heat Gain Controller

Sky temp Air Mixer controller

Psychrometrics Cooling Tower

Pump

WCP

Energy Transfer Plotter

Law Library 2F

Psychrometrics-2

Temperature Plotter

Psychrometrics-3 Figure 6-5: Layout of TRNSYS model for first floor.

Air Change Controller Air Mixer

Psychrometrics-4

Cooling Coil

Psychrometrics-5

Fan

Air Mixer controller

Cooling Tower

Pump

WCP

Energy Transfer Plotter

Figure 6-6: Layout of TRNSYS model for second floor.

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Weather data

Radiation Turn

Heat Gain Controller Sky temp

Psychrometrics

Law Library 3F

Psychrometrics-2

Temperature Plotter

Psychrometrics-3

Air Change Controller Air Mixer

Psychrometrics-4

Cooling Coil

Psychrometrics-5

Fan

Air Mixer controller

Cooling Tower

Pump

WCP

Energy Transfer Plotter

Figure 6-6: Layout of TRNSYS model for third floor. Note: The AHU does not found in TRNSYS studio, the combining of cooling coil and WCP is assumed to represent the AHU of Law faculty library. 6.3.2 Description of modules used in TRNSYS simulation studio Module Type

Description

Inputs and outputs

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Air Change Controller; control the fresh air intake. Air Change Controller

Air Mixer

Air Mixer; mixing the return air from building and the fresh air from ambient then supply to cooling coil.

Inputs: Air flow rate. Outputs: Air change of the building. Input: Return air temperature and humidity ratio, fresh air temperature and humidity ratio, Total air flow rate. Output: Mixing air temperature and humidity ratio, Air flow rate.

Air Mixer controller

Building -Type-56b

Cooling Coil

Air Mixer Controller; control the percentage of fresh air intake.

Input: Percentage of the fresh air.

Multi-zone building; This component models the thermal behaviour of a building.

Inputs: Ventilation air temperature and relative humidity

Outputs: Control signal.

Outputs: Room temperature and relative humidity.

Cooling Coil; cool the mixing Input: Mixing air dry bulb air to the desire off-coil temperature, wet bulb temperature. temperature and air flow rate. Output: Mixing air dry bulb temperature, wet bulb temperature and air flow rate.

Cooling Tower

Cooling Tower; transfer the heat from the system to the ambient

Input: Ambient dry bulb temperature and wet bulb temperature, cooling water temperature and flow rate. Output: Sump temperature and flow rate.

Table 6-2: Modules type Online description. plotter; display the Energy Transfer Plotter

simulation result on monitor.

Inputs: Sensible cooling rate, latent cooling rate, total cooling rate and chiller heat rejection Outputs: Sensible cooling rate, 71

latent cooling rate, total cooling rate and chiller heat rejection profile on screen. Fan; blow the air into the thermal zones of building. Fan

Input: Air dry bulb temperature, relative humidity and air flow rate. Output: Air dry bulb temperature, relative humidity and air flow rate.

Heat Gain Controller; set the number of occupants and Heat Gain Controller computer inside the building.

Input: Number of occupants and number of computer.

Psychrometrics calculator; calculates the rest of the moist air properties with two properties given.

Inputs: Ambient temperature and ambient relative humidity.

Psychrometrics-2

Psychrometrics calculator; calculates the rest of the moist air properties with two properties given.

Inputs: Ambient temperature and relative humidity.

Psychrometrics-3

Psychrometrics calculator; calculates the rest of the moist air properties with two properties given.

Inputs: Return air temperature and relative humidity.

Psychrometrics calculator; calculates the rest of the moist air properties with two properties given.

Inputs: Air mixer temperature and humidity ratio.

Psychrometrics-1

Psychrometrics-4

Psychrometrics calculator; Table 6-2: Modules type description. (continued) calculates the rest of the Psychrometrics-5 moist air properties with two properties given.

Output: Control signal.

Outputs: The rest of the moist air properties.

Outputs: The rest of the moist air properties.

Outputs: The rest of the moist air properties.

Outputs: The rest of the moist air properties. Inputs: Off-coil temperature and temperature.

dry wet

bulb bulb

Outputs: The rest of the moist air properties. 72

Pump

Radiation

Pump; circulate the cooling water from air conditioner system to cooling tower.

Input: Cooling water temperature and flow rate.

Radiation; direct ambient conditions affect to the building.

Input: Ambient conditions.

Sky Temperature; provides the frictive sky temperature.

Input: beam radiation on horizontal and sky diffuse radiation on horizontal.

Sky temp

Output: Cooling water temperature and flow rate.

Output: Control signal.

Output: Beam radiation on the horizontal and diffuse radiation on the horizontal. Online plotter; display the simulation result on monitor. Temp & RH Plotter

Turn

WCP

Outputs: Room temperature and relative humidity profile on screen. Building Position Controller; Control the position of the building.

Input: the position angle of the building.

Water Cool package air conditioning system; provides the cooling capacity to cool the air in the cooling coil.

Input: Temperature and flow rate.

Weather Data Processor; Table 6-2: Modules type description. Combines data(continued) reading, Weather data

Inputs: Room temperature and relative humidity.

radiation processing and sky temperature calculations

Output: Control signal.

Output: temperature and flow rate Inputs: None Outputs: Ambient dry and wet bulb temperature, humidity ratio, relative humidity, wind velocity, total horizontal radiation, etc.

Table 6-2: Modules type description. (continued) 6.3.3

Air Change Rate (ACH) Calculator Module 73

ACH =

m air

ρ s tan dard air x V

(1/hr)

where

ρ s tan dard air = 1.204kg / m 3 V = Volume of zone, (m3)

6.3.4 AHU Cooling coil dimension Area

= Height x width = 1.34 m x 2.20 m = 2.95 m

Number of rows

=4

Number of circuits

= 44

6.3.5 Assumption The assumption were made was to simplify the simulation. There is a lot of uncertainty for the actual situation; however, reasonable assumption will be made to make sure the simulation results are as close as the actual situations. Following are the assumption made: 1. Air volume flow of inlet AHU is 100% blow into the indoor of building. 74

2.

The performance of the air conditioning system is ideal through out the years.

3. There is 20% fresh air of the air conditioning system. 4. The air volume flow rates are equally distributed to each zone in the building. 5. The pumps, fans and cooling tower are performing 100% efficiency. 6. All the conditions of indoor environment remain the same in future. 6.3.6 Results

Figure 6-7: Minimum part load to achieve comfort temperature simulation of law faculty library for year 2000.

Figure 6-7: Minimum part load to achieve comfort temperature simulation of law faculty library for year 2020.

Figure 6-7: Minimum part load to achieve comfort temperature simulation of law faculty library for year 2050. 75

6.3.7 Results summary

Floor GF 1F 2F 3F

Design Cooling capacity. RT 85 72.9 72.5 90.8

Minimum load needed, RT (Year 2000)

Minimum load needed, RT (Year 2020)

Minimum load needed, RT (Year 2050)

47 38 33 43

53 41 35 46

60 45 38 49

Table 6-3: Minimum cooling load to achieve comfort temperature of law faculty library at year 2000, year 2020 and year 2050.

Floor GF 1F 2F 3F

Part load to achieve comfort temperature at year 2000 (%) 55.29 52.13 45.52 47.36

Part load to achieve comfort temperature at year 2020 (%) 62.35 56.24 48.28 50.66

Part load to achieve comfort temperature at year 2050 (%) 70.59 61.73 52.41 53.96

Table 6-4: Part load to achieve comfort temperature of law faculty library at year 2000, year 2020 and year 2050.

Percentage of part Percentage of part load increasing from load increasing from Floor year 2000 to year 2020 year 2000 to year 2050 (%) (%) GF 7.06 15.29 1F 4.12 9.60 2F 2.76 6.90 3F 3.30 6.61 Table 6-5: Percentage of part load increasing of law faculty library.

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6.3.8 Discussion To study the sustainabilty of the air conditioning system and how the climate change impact on it, the worst indoor conditions were taken into considerations. By simulation, the maximum temperature which higher than comfort temperature was identified. Then, minimum part load for worst case to achieve comfort temperature at year 2000, year 2020 and year 2050 were identified. With the part load identified, the percentage increasing of cooling load due to the impact of climate change on the indoor environment of Law faculty library can be calculated. Table 6-4 showed the part load to acheieve the comfort temperature were 55.25%, 52.13%, 45.52% and 47.36% for ground floor, first floor, second floor and third floor respectively at year 2000. From the simulation, the current situations only need 50% of the design cooling capacity to provide comfort environment. From table 6-5, the percentage increasing of part loads were 7.06%, 4.12%, 2.76% and 3.30% for ground floor, first floor, second floor and third floor respectively from year 2000 to year 2020. Besides, the percentage increasing of part loads were 15.29%%, 9.60%, 6.90% and 6.61% for ground floor, first floor, second floor and third floor respectively from year 2000 to year 2050. It showed that the climate change will affect the part load around 2% to 4% ecept for ground floor for next 20 years. Ground floor had the hihgest increasing of part load which was 7.06% for next 20 years because the fraction of glass window to wall of ground floor is high

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compare to other floor. Therefore, higher solar heat gain and radiation heat gain transfer into the indoor environment through the glass window.

6.4 Simulation of Engineering faculty Library 6.4.1 Layout of TRNSYS model of Engineering faculty library

Weather data

Radiation Heat Gain Controller

Turn

Sky temp

Psychrometrics

Engine Library

Psychrometrics-2

Temperature Plotter

Psychrometrics-3

Air Mixer

Psychrometrics-4

Cooling Coil

Psychrometrics-5

Fan

Air Change Controller

Air Mixer controller FCU

Energy Transfer Plotter

Figure 6-8: Layout of TRNSYS model of engineering faculty library Note: The FCU of Engineering faculty library does not found in TRNSYS studio, so, the combining of cooling coil and FCU is assumed to represent the FCU and condensers of actual situation. 6.4.2 Description of modules used in TRNSYS simulation studio

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FCU

Fan Coli Unit air conditioning system; provides the cooling capacity to cool the air in the cooling coil.

Input: Temperature and flow rate. Output: temperature and flow rate.

Table 6-6: Modules type description.

6.4.3 Assumption For study purpose, some assumptions need to make to simplify the complex actual situation. 1. 100% of air volume flow of inlet FCU is blowing into the indoor of building. 2.

The performance of the air conditioning system is ideal through out the years.

3. There is 20% fresh air of the air conditioning system. 4. The air volume flow rates are equally distributed to each zone in the building. 5. The fans are performing 100% efficiency. 6. All the indoor conditions do not change in future. 6.4.4 Results

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Figure 6-9: Minimum part load to achieve comfort temperature simulation of engineering faculty library for year 2000.

Figure 6-10: Minimum part load to achieve comfort temperature simulation of engineering faculty library for year 2020.

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Figure 6-11: Minimum part load to achieve comfort temperature simulation of engineering faculty library for year 2050.

6.4.5 Results summary Design Cooling capacity. RT

Location

Minimum load needed, RT (Year 2000)

Minimum load needed, RT (Year 2020)

Minimum load needed, RT (Year 2050)

Engineerin 62.5 46 50 55 g library Table 6-7: Minimum cooling load to achieve comfort temperature of engineering faculty library at year 2000, year 2020 and year 2050.

Location

Part load to achieve comfort temperature at year 2000 (%)

Part load to achieve comfort temperature at year 2020 (%)

Part load to achieve comfort temperature at year 2050 (%)

Engineering library

73.60

80.00

88.00

Table 6-8: Part load to achieve comfort temperature of engineering faculty library at year 2000, year 2020 and year 2050.

Location

Percentage of part

Percentage of part 81

load increasing from year 2000 to year 2020 (%)

load increasing from year 2000 to year 2050 (%)

Engineerin 6.40 14.40 g library Table 6-9: Percentage of part load increasing of engineering faculty library.

6.4.6 Discussion According to table 6-8, the part load of air conditioning system in Engineering faculty library to achieve comfort temperature were 73.60%, 80.00% and 88.00% at year 2000, year 2020 and year 2050 respectively. From table 6-9, the percentage increasing of part load form year 2000 to year 2020 was 6.40% and the percentage increasing of part load was 14.40% from year 2000 to year 2050 due to the impact of climate change. Compare the percentage increasing of part load between Law faculty library and Engineering faculty library for next 20 years, the results showed the percentage increasing of part load of Engineering faculty library which around 6.40% was higher than percentage increasing of part load of Law faculty library which around 2% to 4%. This is because the glass window to wall fraction of Engineering faculty library is high compare to the glass window to wall fraction of Law faculty library. The glass window to wall fraction of Engineering faculty library is around 75% and the glass window to wall faction of Law faculty library is just around 25%.

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6.5 Chapter summary By TRYSYS simulation, the impact of climate change to the indoor environment at Law faculty library is just around 2% to 4% of its design cooling capacities for next 20 years provide that the air conditioning system is in ideal condition. However, the ground floor had higher impact by climate change which is around 7% increasing of part load for next 20 years because the high glass window to wall fraction. Due to higher fraction of glass window to wall, the increasing of part load at Engineering faculty library is around 7% for next 20 years.

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Chapter 7: Conclusion and Future Work 7.1 Conclusion First of all, the field work was carried out at Law faculty library and Engineering faculty library. The parameters measured were temperature, relative humidity, CO2 concentration, CO concentration, air flow, and volume flow rate. Found that the temperature was lower than comfort temperature and the relative humidity was high in the library. Other parameters such as CO2 concentration, CO concentration, air flow were fulfilled the ASHRAE Standard. On the other hand, Engineering faculty library had higher temperature than comfort temperature. Relative humidity, CO2 concentration, CO concentration and air flow were in acceptable condition. Secondly, heat load calculation is used to calculate the design cooling capacities and can not use to estimate and predict the future conditions of the libraries. From the heat load calculation at chapter 5, it showed the total heat gain 84

needed for Law faculty library only around 50% of the design cooling capacities. Mean that, the safety factor used in cooling capacities design was two. On the other hand, the percentage of total heat gain over the design cooling capacities of the Engineering faculty library was 62.69%. To have a clear picture of the impact of climate change on the building in future, the TRNSYS simulation is needed. Due to the complexity of the actual situations, some assumptions were made to simplify the situations for the study purpose. By TRYSYS simulation, the results showed only 2% to 4% part load had increased due to the impact of climate change to the indoor environment at Law faculty library for next 20 years. However, the ground floor had higher impact by climate change which is around 7% increasing of part load for next 20 years because the high glass window to wall fraction. Besides, part load of Engineering faculty library will increase around 7% for next 20 years due to higher fraction of glass window to wall. As a conclusion, the climate change will be one of the factors to affect the indoor environment. It will gives impact and increases part load of the buildings around 2% to 7% in hot and humid tropical climate country for next 20 years.

7.2 Recommendation and Future Work The sustainability of the air conditioning system depends on a lot of factors such as the system design, system maintenance, location and also climate change. There are no monitoring systems for air conditioning system in both of libraries. For

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more accuracy of research, the monitoring devices need to put at the field work site to monitor the system for a certain periods. Due to lack of WCP and FCU air conditioning system in TRNSYS studio, create the new modules for this two systems are needed.

The comparison of

TRNSYS simulation results with the performance curve of actual situations needed to carry out to verify the result of simulations.

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