BS (Arch) l Building Science : Human Perception of Comfort Level

BUILDING SCIENCE 1 (ARC 2412)

Project 1: Human Perception of Comfort Level

The Report

Muhammad Naim Ahmad Mukif

0303348

Arif Zakwan Abdul Hamid

0303736

Muhammad Arif Shafii

0303005

Sonia Gala Alai Mariam Gerawat

0304827

Oh Keng Yee

0312501

Siti Munirah Zazarin

0312710

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Table of Contents

Summary…………………………………………………………………………………………………………………………………….. 3 Introduction………………………………………………………………………………………………………………………………… 4 Methodology………………………………………………………………………………………………………………………………. 5 Site Introduction…………………………………………………………………………………………………………………….…… 8 Orthographic Projections………………………………………………………………………………………………………………………………… 9 Results and Analysis Raw Data…………………………………………………………………………………………………………………………………… 12 Bioclimatic Chart……………………………………………………………………………………………………………………….. 17 Thermal Balance……………………………………………………………………………………………………………………..…. 18 Ventilation………………………………………………………………………………………………………………………..………. 22 Thermal Analysis………………………………………………………………………………………………………………………. 24 Conclusion……………………………………………………………………………………………………………………………….. 43 References………………………………………………………………………………………………………………………………. 44 Appendix…………………………………………………………………………………………………………………………………… 45

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Summary In this project, we are to find the ‘thermal comfort’ of inhabitants of a certain space. Thermal comfort is defined as ‘a feeling of well -being.’ 1 To determine this state of well-being, one is affected by several factors which can be categorized into personal, measurable environmental, as well as psychological influences. In other words, the data collected are both quantitative as well as qualitative.

A bedroom in an apartment is chosen as the site for this experiment. The quantitative data such as temperature and relative humidity (RH) are recorded in the respective room using a thermohygrometer.

This information is then interpreted into a bioclimatic chart to determine whether or not the resident is living in comfort. Other factors used to analyze thermal comfort include human activity and clothing.

The inhabitant’s response towards the site (qualitative data) will also be taken into consideration. Apart from that, diagrams which illustrate the sun path, wind rose, heat gain and heat loss are also used to assist in coming up with a conclusion regarding thermal comfort. Throughout this project, the analyses made are all done in reference to the MS 1525 2; a code of practice evaluating the energy efficiency of a building, as well as the Uniform Building By-Laws (UBBL) 3.

1

T. Grondzik, W., Stein, B., G. Kwok, A. and S. Reynolds, J. 2010. Mechanical and Electrical Equipment for Buildings. 11th ed. New Jersey: J. Wiley & Sons, p. 91-92

2 http://www.docstoc.com/docs/37865664/GREEN-BUILDING-INDEX-MALAYSIA-MS-1525-2007-ACMV-System 3 https://attachment.fbsbx.com/file_download.php?id=208902282617111&eid=ASuaRbwshg2z2p9zETyZYMX1Ci5g7HRHIzCCbqEOb25q1EEDKdxXggiKagUk2zSP68&inline=1&ext=1380658271&hash=A SszZwdsaF3KtxaK

3

Introduction

Our chosen site is a bedroom in an apartment unit on the ground floor of Block A, Mutiara Perdana located in PJS7, Bandar Sunway. We used a Data Logger to measure the indoor temperature and relative humidity levels of chosen room, in which measurements were taken for three consecutive days (13th to 16th September). Though the data logger records the temperature and relative humidity continuously, for the purpose of this report, we are to analyse the data between 10pm to 6 am for the respective days. We then use the results to plot the point of thermal comfort in a bioclimatic chart.

According to the Malaysian Standard 1525 act, thermal comfort is the “condition of mind which expresses satisfaction with the thermal environment”. Our task is to evaluate the current conditions of thermal comfort and propose different strategies that could improve it. Thermal comfort is quite difficult to be given an exact value to as it differs from person to person - each person may experience comfort at different humidity or temperature levels. Nevertheless, the data and analysis collected in this report will surely improve our understanding of thermal comfort, hence allowing us to adapt sustainable design strategies.

Hypotheses In this research, we predict and will either prove or disprove that: •

The relationship between temperature and relative humidity is inversely proportional.

•

The chosen unit is cooler than the upper floors and is within the comfort level due to it being on the ground floor (prediction based on the idea of shadow cast from upper floors and that the fact that hot air rises)

Limitations •

Human error in handling the data logger

•

Sudden weather change

•

Limited time frame of data collection, hence less variation in data

4

Methodology In completing this project, several methods of investigation are carried out. These range from sourcing material available online to measuring the data manually.

Data Logger

Figure 1: Data Logger

This instrument is normally used to record several factors which affect thermal comfort (such as, but not limited to: air temperature, surface temperature, air motion and relative humidity levels).

For the purpose of this experiment, the data logger was used to obtain data in the following areas: -

Relative Humidity (RH) Indoors

-

Temperature Indoors

5

Its usage is fairly straightforward and steps were taken as follows:

Figure 2: placement of Data Logger

1) Set the data logger to the current date and time 2) Set to record data at one-hour intervals 3) Select to record indoor temperature and relative humidity levels 4) Place device in the center of the room at a height of 1m from ground level 5) Retrieve data after a period of three days

Additional data required such as temperature of the site and the relative humidity levels outdoors was obtained from meteorological data available on the internet.

Visual Presentation of Data

6

Visual aids were used to clarify the relationship between the data collected. Methods used are as follows: -

Line graphs

-

Diagrams

Figure 3 : Data collected from the Data Logger

Mainly line graphs were used with the help of tables to compare the data collected across the three day period. These graphs were plotted with the data collected both by the data logger and those found from meteorological sites online. It is especially effective in conveying the correlation or relationship between the different fields of data.

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Figure 4 : Wind Rose Diagram & Heat Loss/Gain Diagram

For more complex data like the sun path in the area of the site as well as the wind speed, various diagrams were used to show the data collected. With regards to the sun path, diagrams produced with the program Ecotect proved most effective. When showing wind speed throughout the month, the clearest way was to show it through a wind rose diagram.

Orthographic Drawings The site chosen is a rented unit and as such had no plans available to us. To overcome this, we measured the site and produced sketches and drawings to further aid in explaining our results.

Figure 5 : Site Context & Orthographic Drawings

8

Items drawn range from plans to sections as well as elevations.

Miscellaneous Other data without numerical values such as human activities and items of clothing worn were noted down to ensure all parts of the experiment were covered.

Site Introduction The site that we have chosen is located in PJS 7/15, Bandar Sunway. PJS is a residential area in an urban environment, consisting of mainly flats, apartments and terrace houses. Apart from that, there are also schools and shop lots to cater for the residents of the area. Due to it being of walking-distance to a nearby university, it is an ideal choice for student accommodation.

Looking at Mutiara Perdana apartment specifically, it is considered a high-density living space as most of the units are occupied.

9

Site Context

The highlighted area in the diagram above illustrates our chosen area of research.

Macroclimate Malaysia, being an equatorial country experiences high humidity and temperature, with average annual temperature of 27째C and receives an average rainfall of 2500mm. Having this tropical climate, buildings, of course must be designed to suit the climate in order to achieve maximum thermal comfort. Due to it being warm all-year round, it is an ideal design consideration to keep the building cool, rather than to heat it. Without doubt, electrical methods of cooling such as air-conditioning or using a fan are effective ways to cool a space. However, natural factors such as wind ventilation, smart choices of building materials can help buildings offer better comfort in hot climates more sustainably.

Microclimate The following table displays site-specific climate information.

Day Outdoor RH (%) Indoor RH (%) Outdoor Temperature (째C) Indoor Temperature (째C)

Highest 100 74.4 26 29.6

1 Lowest 94 72.8 25 28.9

Mean 95.3 73.8 25.4 29.3

Highest 100 74.4 25 30.4 10

2 Lowest 84 74.1 24 29.1

Mean 92.4 74.2 24.6 29.7

Highest 94 71.6 27 29.4

3 Lowest 74 43.4 24 25.6

Mean 86.2 54.6 25.4 27.5

Meteorological data of PJS7, Bandar Sunway, Subang Jaya

From this table, we can see that

indoor

temperature is always higher than the temperature outside.

On the other hand, the indoor relative humidity is lower than that

of

the outdoor’s. As mentioned earlier, Malaysia has an average annual temperature of 27°C. In this table, however, it is observed

that

mean outdoor temperature is 25°C. This will be further analyzed in

the

report.

Orthographic Projections The following are orthographic projections generated to assist us in analyzing thermal comfort.

Results and Analysis DAY 1 Time

Indoor RH (%)

Outdoor RH (%)

Indoor Temperature (°C)

Outdoor Temperature (°C)

External Conditions

22:00:21

72.8

94

29.6

25

Passing clouds / warm

23:00:24

73.2

100

29.5

25

Passing clouds / warm

0:00:27

73.7

94

29.4

26

Passing

11

clouds / warm 1:00:30

73.9

100

29.4

26

Passing clouds / warm

2:00:33

73.9

94

29.3

26

Passing clouds / warm

3:00:36

74

94

29.2

26

Passing clouds / warm

4:00:40

74.2

94

29.1

25

Passing clouds / warm

5:00:43

74.4

94

29

25

Partly sunny / warm

6:00:46

74.4

94

28.9

25

Partly sunny / warm

Raw Data Collected

DAY 2

12

Time

Indoor RH (%)

Outdoor RH (%)

Indoor Temperature (째C)

Outdoor Temperature (째C)

External Conditions

22:00:35

74.2

84

30.4

25

Light rain

23:00:38

74.3

84

30.1

25

Mostly cloudy / warm

0:00:41

74.2

94

29.9

25

Partly cloudy / warm

1:00:45

74.2

94

29.8

25

Partly cloudy / warm

2:00:48

74.2

100

29.6

25

Partly cloudy / warm

3:00:51

74.1

94

29.5

24

Partly cloudy / mild

4:00:54

74.1

94

29.4

24

Partly cloudy / mild

5:00:57

74.3

94

29.2

24

Partly cloudy / mild

6:00:00

74.4

94

29.1

24

Passing cloud / mild

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DAY 3 Time

Indoor RH (%)

Outdoor RH (%)

Indoor Temperature (째C)

Outdoor Temperature

External Conditions

(째C) 22:00:50

71.6

74

29.4

27

Partly cloudy / warm

23:00:53

66.3

79

27.7

27

Broken clouds / warm

0:00:56

59.1

84

27.3

26

Partly cloudy / warm

1:00:59

56.4

84

28.1

26

Partly cloudy / warm

2:00:02

49.4

84

26.7

26

Partly cloudy / warm

3:00:05

48.6

89

27.4

25

Partly cloudy / warm

4:00:08

49.1

94

27.3

24

Partly cloudy / mild

5:00:11

43.4

94

25.6

24

Partly cloudy / mild

6:00:14

47.8

94

27.6

24

Partly cloudy / mild

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Based on the raw data collected, a graph is produced to observe the patterns of thermal comfort throughout the three days.

Day

1

2

3

Highest

Lowest

Mean

Highest

Lowest

Mean

Highest

Lowest

Mean

Outdoor RH (%)

100

94

95.3

100

84

92.4

94

74

86.2

Indoor RH (%)

74.4

72.8

73.8

74.4

74.1

74.2

71.6

43.4

54.6

26

25

25.4

25

24

24.6

27

24

25.4

29.6

28.9

29.3

30.4

29.1

29.7

29.4

25.6

27.5

Outdoor Temperature (째C) Indoor Temperature (째C)

An analysis of the data over the three days is fairly regular with the exception of the third day being an anomaly. Looking at the mean values calculated, it can be observed that the indoor humidity levels and temperature are affected by the state of humidity and temperature outside the room although they are not in direct correlation. There was rainfall recorded on the second day at roughly 01:00 hours. This accounts for the spike in humidity on the second day, and the subsequent decrease in relative humidity levels after. This will be further explained below.

Based on various findings, rainfall leads to a drop in temperature but an increase in relative humidity levels. After the rain however, humidity levels tend to drop as moisture in the air evaporates, forming rainclouds. This subsequently leads to more rain. Of course this is only a very basic explanation on the effect of humidity levels on rain, there are many other factors to consider.

Rainfall occurs on day two, in line with the spike in relative humidity levels outdoor. The temperature outdoor is also seen to drop during this time. After a whole day, the moisture in the air is assumed to 15

have evaporated as the humidity levels drop drastically. This assumption is further reinforced by the increase in temperature, showing the absence of rain on day three.

The trend of the graph for outdoor humidity is more erratic throughout the three days but the value maintains on the high side. This is not reflected on the indoor humidity levels as the graph shows a stable reading for the first two days. On the third day, the indoor humidity decreases drastically as the user spent less time in the room compared to the first two days. This also accounts for the drop in indoor temperature.

Indoor Temperature

Outdoor Temperature

(°C)

Indoor Relative Humidity (RH) (%)

DAY 1

29.27

73.83

25.44

95.33

DAY 2

29.67

74.22

24.56

92.44

DAY 3

27.46

54.63

25.44

86.22

Mean

28.8

67.56

25.15

91.33

(°C)

Outdoor Relative Humidity (RH) (%)

In terms of temperature, however, the outdoor temperature was constant, hovering around the 25°C mark all three days. The indoor temperature was significantly higher indoors, a good 4°C increase compared to the temperature outside the building. The windows of the building were noted to be open during the day and closed during the night, which is the period the experiment was conducted. The closed windows prevented cross ventilation and could be the cause of increased indoor temperature.

The user’s room is located on the ground floor and the building it is located in is surrounded by various other buildings, so the wind flow is limited compared to those on a higher floor. This could have also contributed to the increase in indoor temperature.

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Bioclimatic Chart

Indoor Bioclimatic Chart

From the intersection of the line, it is understood that the inhabitant is outside the comfort zone most of the time probably due to high humidity percentage and temperature. The cause of such conditions could be the low efficiency of the room’s ventilation system, as the room is only fitted with one window.

Other factors include the furnishing and the building materials used in the room. The window was shut and covered by a curtain throughout the data recordings. The window is fitted with tempered glass - this keeps heat from escaping, therefore slows down heat loss. This is one of the contributing factors to the high indoor temperature. Humidity levels are moderately high due to the fact that is not well-ventilated (i.e. closed windows) during the night. Nevertheless, in the MS 1525, it is stated that the RH for indoor comfort condition should not exceed 70%. Based on this requirement, the RH in the room is tolerable

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Sun Path Analysis

Site Plan N.T.S As seen in the site plan, the building selected is surrounded by other buildings and parking lots. The lack of nature in this scenario contributes to the high indoor temperature readings obtained by the data logger. However, the surrounding buildings provide a certain amount of shade at various times during the day.

Chosen Unit

Figure E: Sun path

simulation of

building at 09:00

hours, September

15th, 2013

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Figure E shows that the shadow casts provided by the surrounding blocks at 09:00 hours are mainly for the side of the building. The length of shadow cast is fairly short but sufficient to shade the various openings.

There are openings located on the North-West, North-East and South-West side of the building. The frequencies of these openings are the same for every floor. The South side is attached to the neighboring block and as such has no visible openings. This prevents heat from entering from this direction but also blocks any heat from escaping from here.

The morning sun does not reach any of the openings of the unit. The unit in front of and adjacent to the chosen site is protected and hence is not subjected to the morning sun. Hence, it is assumed that the unit is not affected by the morning sun.

Figure F : Sun path and shadows at 12:00 hours, September 15th 2013 The unit is exposed to more sunlight as the sun peaks at mid-day. The South-West wall of the room is exposed to the full blast of the afternoon sun. The intensity of the afternoon sun penetrates the walls and will cause an

increase in the indoor

temperatures

the room. The North-

Western

of wall

however

coverage from the

has

slight

presence of an awning.

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North Western wall

Figure G : Sun Path and shadowing of unit at 16:00 hours, September 15 th 2013

At 16:00 hours, the chosen unit is exposed to direct sun light on the north western wall which contains a window and a small awning. The presence of said awning cuts down the amount of sunlight penetrating the building at the given time. Due to its location, the kitchen sits in the shadow of the surrounding buildings.

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March 15th

March 15th

March 15th

9am

12pm

4pm

July 15th

July 15th

July 15th

9am

12pm

4pm

September 15th

September 15th

9am

12pm

21

September 15th 4pm

Sun Path Diagrams throughout the Year

Wind Analysis

The Wind Rose Diagram

Based on the diagram, throughout the month of September, typical wind speed varies from 10 km/h to 55 km/h. The lowest wind speed is at 10km/h with a high frequency that occurred for less than an hour. As for the highest wind speed, it is 55km/h with also a high frequency. According to the highest wind speed, the wind flows from two directions North West to South East and North to South. The average of wind speed is about 30km/h. Prevailing North West to South East, the wind flows directly into the unit through the entrance facing the West and the wind movement escapes through the back where the toilet is facing the East.

22

Wind rose diagram on site map

Wind flow around site

23

The figure above indicates that the major wind flows from two directions which are, from North West to South East and from North to South. As the direction of the wind flows from the main entrance and the security guard post, the wind tends to be warmer coming from the main road near the main entrance.

However, the wind is less warm from the security guard post towards Block A whilst the guard post is partly surrounded by trees and shrubs.

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Ventilation

The presence of opening at different sections of the unit promotes air movement, which, in turn, increases thermal comfort of a user. This is due to the replacement of air that occurs during cross ventilation.

Cross Ventilation in the unit shown on plan

As a new batch of cool air enters the unit from one side of the unit, the stale, warmer air is pushed out another, usually located opposite the window fresh air entered. This exchange causes movement in the air, thereby reducing humidity significantly and causing an increase in human thermal comfort.

25

Section showing the flow of air with the red arrow representing warm air, and the blue, cold.

The basic gist of things is that hot air rises. There will always be a certain amount of air that is warmer in relation to its surroundings, hence, air movement will always occur. The key in determining thermal comfort is the degree of air movement in a given place. The movement of hot air to the top and cold to the bottom is commonly known as heat convection. This phenomenon is further promoted by air movement. In general, the higher the degree of air movement, the higher the degree of heat convection, and in turn this contributes to an increase in thermal comfort.

Due to the lack of air movement in the case study, thermal comfort is on the lower end of the spectrum as the speed at which heat convection occurs is low. The hot air rises at a slow pace and heat is dispelled out of the unit slower. This causes a rise in temperature inside the unit.

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The opening in the kitchen facing East is the main opening of the unit. However, due to the positioning of the building, air flow is blocked by the surrounding buildings and as such air movement is hindered.

This causes poor air circulation even though the window is left open.

Left – Right : Opening located in kitchen. Opening located in bathroom.

While the window in the bathroom is also left open most of the time, the bathroom door is closed. This is a fairly common practice amongst Malaysians today as doors are kept closed whenever possible due to safety reasons. These shut doors become and obstacle for air movement and prevent optimal cross ventilation to occur. The result is a stuffy home, one that is humid and slightly warm. Thermal comfort is at a low point.

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Thermal Balance

To be in a state of thermal balance, the heat loss must equate to the heat gained by the occupant. Of course one must take into account the psychrometric qualities that affect thermal comfort but for the purpose of this section, they will be assumed to be constant for all.

Thermal Heat Transfer Solar Radiation Heat is transferred to an occupant through various ways. In the tropical climate of Malaysia, solar radiation is a major factor of heat transfer. It is essentially electromagnetic energy that travels in the form of light and heat. In the case study, the window in the kitchen faces East. This causes the kitchen to receive the full brunt of the morning sun. Despite the presence of awnings, the temperature in the unit 28

increases due to exposure to direct sunlight. The lack of casement windows also contribute to overall hermal discomfort in the unit, especially from 08:00 hours to 12:00 hours

Thermal Radiation This is the heat produced by objects while being in use. These objects radiate heat that add to the thermal heat transfer equation. Everyday items, especially those of electronic nature, causes heat gain to the occupant of the unit.

These items include, but are not limited to:

-

Wifi Routers

-

Desktop Computers

-

Lighting units

29

Cross-

Ventilation

inlet

outlet

30

Based on the wind rose diagram, it is observed that the location of the building causes the bedroom to receive maximum wind exposure as the highest wind velocities come from the north-west (which is the direction the bedroom window faces). To evaluate the effect of cross-ventilation on thermal comfort, the MS 1525 is referred to. Clause 4.6.1 states the following design recommendations: a) Orientate the building to maximize surface exposure to prevailing winds b) Provide inlets on the windward side (pressure zone) and outlets on the leeward side (suction zone). c) Use architectural features like wing walls and parapets to create positive and negative pressure areas to induce cross ventilation. d) Provide openings on opposite walls for optimum cross ventilation effectiveness. However, if this is not possible, openings can be placed on adjacent walls. e) Make openings easily accessible and operable by the occupants. f) Avoid obstructions between inlets and outlets g) Have equal inlet and outlet areas to maximize airflow h) Make outlet openings slightly larger than inlet openings to produce higher air velocities i) Locate outlet openings on the windward side at the occupied level

Looking at the recommendations above, there are some factors that are present in the chosen bedroom, and there are factors that are not. For instance, clause 4.6.1(a) mentions the orientation of the building to achieve maximum thermal comfort. Based on our wind rose diagram, this is successfully achieved.

Clause 4.6.1(d) is also successfully represented in the room, which is that openings should be placed on opposite walls. In our case, the bathroom window is parallel to the bedroom window, hence increases thermal comfort.

An example where the design features of the room do not coincide with MS 1525 is in clause 4.6.1(h). It is recommended that outlet openings should be slightly larger than inlet openings to increase thermal comfort. In the case of the chosen room, it is the other way round. Thus, a design proposal to increase thermal comfort would be to increase the number of inlets and outlets to maximize airflow in the room.

31

Material Analysis

32

Materials Component

Material

Thermal Conductivity (W/mK)

Walls

Concrete (general)

1.28

Windows

Laminated Glass

0.93

Window Frames

Aluminium

237

Tiles

Ceramic

1

Door

Plywood

0.16

Ceiling

Gypsum

0.16

Table 1.0 : Thermal Conductivity of Materials in the Room

The different materials used in the room depict different thermal performances (Table 1) that can affect the thermal condition of the space within the building. Processes of heat transfer such as conduction, convection and radiation in materials are explained as follows.

K-Value : Thermal Conductivity A value that measures the speed of thermal conductivity across any given material. This is affected by the density of the material.

33

The denser a material, the higher the K-Value.

A higher K-Value translates to being a good conductor of heat. Conversely, materials with low KValues are said to be good insulators of heat.

Based on the collected information and what is understood of the K-Value, it is seen that the component in the room that conducts the most heat are the aluminium window frames with a K-Value of 237, followed by the masonry walls with a K-Value of 1.28. The components which conduct the least heat are the plywood door and gypsum ceiling which both have a K-Value of 0.16.

From this information, it can be concluded that aluminium is not the best material choice due to its high conductivity, which decreases thermal comfort. A design proposal to improve thermal comfort would be to use a less conductive material, such as a PVC window frame.

It is worth noting that the furnishings used in the room, such as a bamboo mat and polyester curtains may have affected thermal comfort, though not greatly.

R-Value : Thermal Resistance A value used to measure the thermal resistance of a particular material.

In general, the higher the R-value of a material, the higher the thermal insulation it provides.

R = X/K SI unit = m2路K/W R = Thermal Resistance (m2K/W) X = Thickness of the Materials (m) K = Thermal Conductivity of the Materials

Materials Component

Material 34

R-Value

Walls

Concrete (general)

0.12

Windows

Laminated Glass

0.02

Window Frames

Aluminum

0.0003

Tiles

Ceramic

0.01

Door

Plywood

0.25

Ceiling

Gypsum

1.875

A quick tabulation of the R-Value of building materials used show how well these materials resist heat. In line with our findings when calculating the K-Value, aluminum is not the best choice for window frames in terms of thermal resistance. The R-Value of aluminum is incredibly low, highlighting its vulnerability in absorbing, and conversely, dispelling heat to the environment.

From the table it is seen that the laminated glass and ceramic are in the same category in terms of providing thermal insulation whereas plywood and concrete prove to be more efficient in this category. The highest value, however, goes to gypsum with a staggering 1.875 R-Value.

Overall, most materials selected for the building has a low R-Value. This means that the building has low thermal insulation and is not efficient in terms of energy saving. Not only does this result in more energy spent to cool the place(with the use of fans and air-conditioning), it also causes a loss of uniformity in temperature from the floor to ceiling height.

This in turn will cause a rise in temperature, increase in relative humidity levels and ultimately, a decrease in human thermal comfort.

U-Value : Heat Transfer A value that measures the amount of heat transferred through a building over a pre-determined area.

35

U=1/R SI unit = W/(m2K)

Materials Component

Material

U-Value

Walls

Concrete (general)

8.33

Windows

Laminated Glass

50

Window Frames

Aluminium

3333.3

Tiles

Ceramic

100

Door

Plywood

4

Ceiling

Gypsum

0.53

The U-Value is the inverse of the R-Values found earlier in the report. Thus, it can be concluded that the lower the U-Value, the better the thermal insulation provided by the material.

Findings are in line with that of the R-value. The ranking of thermal insulation, with the worst lined first, is as follows:

Aluminium < Ceramic < Laminated Glass < Concrete < Plwood < Gypsum

However if we look at the data collectively, it can be assumed that the overall U-value of the building is on the higher end. This brings us to the conclusion that the building is not well insulated.

36

Table 1.0 : Thermal conductivity and densities of common building materials.

37

Convection The transfer of heat, applicable in the liquid and gaseous states. Particles in these two states travel in the Brownian Motion, ie, particles are free to move randomly and collide with one another. Heat is transferred from one molecule to another during these collisions.

Conduction The transfer of heat, only applicable to solids. Heat transfers across molecules, generally from a cooler region to a warmer region when the particles vibrate against one another.

Radiation The transfer of heat across a vacuum. Solar radiation is an example of this.

The Stefan Boltzmann law is a formula that calculates radiation of a material.

Q = (5.673x 10-8) x E x T4

Q = Radiation emitted by the surface E = Emissivity (amount of radiation by a surface compared to a black body at same temperature) T = Surface temperature (oC) Constant = 5.673 x10-8 W/m2K4

38

The radiation emitted by a material is directly proportional to the emissivity and temperature of a surface. In simpler terms, if the surface temperature and the emissivity is high, the material will radiate heat to its surroundings.

Table 2.0 : Table showing the emissivity of various materials

Thermal Capacity The measure of the amount of heat stored by a material from its surroundings.

The higher the volume and density of a material, the higher its thermal capacity.

Thermal Capacity = Volume . density . specific heat (J/kg.K) 39

SI unit = J/K.m3

Table 3.0 : Density, specific heat capacities and thermal conductivity of common building materials

40

DAY 1 Time

Clothing Ensemble

22:00:21

Clothing Value

Human Activity

Metabolic Rate (W/m2)

Trousers, shortsleeve shirt

0.57

Resting -Seated, quiet

60

23:00:24

Trousers, shortsleeve shirt

0.57

Resting Reclining

45

0:00:27

Trousers, shortsleeve shirt

0.57

Resting Reclining

45

1:00:30

Trousers, shortsleeve shirt

0.57

Resting - Sleeping

40

2:00:33

Trousers, shortsleeve shirt

0.57

Resting - Sleeping

40

3:00:36

Trousers, shortsleeve shirt

0.57

Resting - Sleeping

40

4:00:40

Trousers, shortsleeve shirt

0.57

Resting - Sleeping

40

5:00:43

Trousers, shortsleeve shirt

0.57

Resting - Sleeping

40

6:00:46

Trousers, shortsleeve shirt

0.57

Resting - Sleeping

40

Other Factors Affecting Thermal Comfort

Note: There were three occupants in the room on this day.

DAY 2 Time

Clothing Ensemble

Clothing Value

Human Activity

Metabolic Rate (W/m2)

22:00:35

-

-

-

-

23:00:38

-

-

-

-

0:00:41

-

-

-

-

41

1:00:45

-

-

-

-

2:00:48

-

-

-

-

3:00:51

-

-

-

-

4:00:54

-

-

-

-

5:00:57

-

-

-

-

6:00:00

-

-

-

-

Note: The inhabitant was not at home on this day.

DAY 3 Time

Clothing Ensemble

Human Activity

Metabolic Rate (W/m2)

0.57

House Cleaning

115-200

0.57

Reading, seated

60

23:00:53

Trousers, shortsleeve shirt

0.57

Resting Sleeping

40

0:00:56

Trousers, shortsleeve shirt

0.57

Resting Sleeping

40

1:00:59

Trousers, shortsleeve shirt

0.57

Resting Sleeping

40

2:00:02

Trousers, shortsleeve shirt

0.57

Resting Sleeping

40

3:00:05

Trousers, shortsleeve shirt

0.57

Resting Sleeping

40

4:00:08

Trousers, shortsleeve shirt

22:00:50

Trousers, shortsleeve shirt

Clothing Value

42

0.57

Resting Sleeping

40

5:00:11

Trousers, shortsleeve shirt

0.57

Resting Sleeping

40

6:00:00

Trousers, shortsleeve shirt

As there was very little variation in the clothing ensemble and activities carried out, we felt that they do not highly affect our research.

Standard Building Design In accordance with the Malaysian UBBL, the building design has to take into account the thermal comfort of occupants. The building chosen was analyzed to investigate if it fit into the standard building design highlighted in the UBBL. Findings are as follows:

Clause 39 : Natural Lighting and Ventilation The number of openings in a building is dictated by its floor area. UBBL states that natural ventilation

43

and lighting provided must be more than 10% of the total clear floor area. Such openings are also required to have an uninterrupted air flow no less than 5% of the floor area.

Figure 3.11: Openings in Elevation Total area of windows and doors = 4.09 m 2 Area of clear floor with data logger = 7.5 m 2 Natural lighting and ventilation (%) = 4.09/7.5 X 100% = 54.5%

Figure 3.13: Area of clear floor with data logger

2. Clause 42 : Minimum area of rooms Using the UBBL as reference, the minimum width of a room has to be no less than 2 meters for it to be considered to be habitable.

Note that the room chosen room has a width of 4.57m.

3. Clause 44(1)(a) Height of rooms in residential buildings The minimum height of a room in residential buildings is 2.5 meters, as stated in the UBBL. The 44

measured height of the chosen room is 2.8m, a clear 0.3m more than the minimum requirement.

Conclusion To conclude the project, we have discovered that the inhabitant of the space is not living within the comfort zone. Based on bioclimatic chart and the MS 1525, it is evident that to achieve better thermal comfort, the indoor temperature as well as relative humidity has to be of a lower value. Ways that this can be achieved is by improving the cross-ventilation in the building. For example, the addition of windows may help achieve this. Also, the choice of materials can be improved. We suggest that PVC window frames to be used instead of the existing aluminium ones.

A positive factor that contributes to thermal comfort is the positioning of the building. Based on our wind analysis, we have discovered that the buildingâ&#x20AC;&#x2122;s orientation allows maximum wind velocity to enter the room.

There were several limitations to the project, especially in terms of data collection. Firstly, there was a lack of human activities, thus it did not show much variation in data. A way in which we could have improved on this was to carry out different activities to show how the metabolic rate affects our investigation.

45

During the days of data recording, we felt that the weather was not constant during the hourly intervals.

For example, on the three days, there were thunderstorms, cloudy days and sunny days. These random occurrences may have affected the results. To add to that, the time frame given in this project was limited, which was from 10pm to 6am. We feel that if we had analyzed the whole day instead, more patterns of data can be obtained. Finally, we were not familiar with the use of the device; the data logger. We feel that our limited knowledge on the device may have delayed our progress during the research.

References

Aquino, M. (n.d.). Weather in Malaysia. Retrieved from http://goseasia.about.com/od/malaysia/a/wmalaysia.htm

T. Grondzik, W., Stein, B., G. Kwok, A. and S. Reynolds, J. 2010. Mechanical and Electrical Equipment for Buildings. 11th ed. New Jersey: J. Wiley & Sons, p. 91-92

http://www.docstoc.com/docs/37865664/GREEN-BUILDING-INDEX-MALAYSIA-MS-1525-2007-ACMVSystem

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https://attachment.fbsbx.com/file_download.php?id=208902282617111&eid=ASuaRbwshg2z2p9zETyZYMX1Ci5g7HRHIzCCbqEOb25q1EEDKdxXggiKagUk2zSP68&inline=1&ext=138065827 1&hash=ASszZwdsaF3KtxaK

Appendix

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