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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
Introduction4
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
Appendix45
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Summary
In this project, we are to find the thermal comfortof inhabitants of a certain space. Thermal
comfort is defined as a feeling of well -being.1To 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 inhabitants 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 15252; a code of practice evaluating the energy efficiency of a
building, as well as the Uniform Building By-Laws (UBBL)3.
1T. 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
2http://www.docstoc.com/docs/37865664/GREEN-BUILDING-INDEX-MALAYSIA-MS-1525-2007-ACMV-System
3https://attachment.fbsbx.com/file_download.php?id=208902282617111&eid=ASu-
aRbwshg2z2p9zETyZYMX1Ci5g7HRHIzCCbqEOb25q1EEDKdxXggiKagUk2zSP68&inline=1&ext=1380658271&hash=A
SszZwdsaF3KtxaK
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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 (13thto 16thSeptember). 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 toevaluate 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
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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
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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 time2) Set to record data at one-hour intervals3) Select to record indoor temperature and relative humidity levels4) Place device in the center of the room at a height of 1m from ground level5) 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
Visual aids were used to clarify the relationship between the data collected. Methods used are as
follows:
- Line graphs- Diagrams
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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.
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.
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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
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.
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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.
Site Context
The highlighted area in the diagram above illustrates our chosen area of research.
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Macroclimate
Malaysia, being an equatorial country experiences high humidity and temperature, with average annual
temperature of 27C 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.
Day1 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
Outdoor Temperature (C) 26 25 25.4 25 24 24.6 27 24 25.4
Indoor Temperature (C) 29.6 28.9 29.3 30.4 29.1 29.7 29.4 25.6 27.5
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 outdoors.As mentioned earlier,
Malaysia has an average annual temperature of 27C. In this table, however, it is observed that mean
outdoor temperature is 25C. This will be further analyzed in the report.
Meteorological data of PJS7, Bandar Sunway, Subang Jaya
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Orthographic Projections
The following are orthographic
projections generated to assist us inanalyzing thermal comfort.
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Results and Analysis
Raw Data Collected
DAY 1Time 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
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
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DAY 2
Time Indoor RH (%) Outdoor RH
(%)
Indoor
Temperature (C)
Outdoor
Temperature (C)
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
(C)
Outdoor
Temperature
(C)
External Conditions
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 3Highest Lowest Mean Highest Lowest Mean Highest Lowest Mea
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
Outdoor Temperature (C) 26 25 25.4 25 24 24.6 27 24 25.4
Indoor Temperature (C) 29.6 28.9 29.3 30.4 29.1 29.7 29.4 25.6 27.5
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.
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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
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.
In terms of temperature, however, the outdoor temperature was constant, hovering around the 25C
mark all three days. The indoor temperature was significantly higher indoors, a good 4C 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 users 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.
Indoor
Temperature
(C)
Indoor
Relative
Humidity
(RH) (%)
Outdoor
Temperature
(C)
Outdoor
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
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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 rooms ventilation system, asthe 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 - thiskeeps 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.
Figure E: Sun path simulation of building at 09:00 hours, September 15th
, 2013
Chosen Unit
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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 theunit is not affected by the morning sun.
Figure F : Sun path and shadows at 12:00 hours, September 15th2013
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 of the room. The North-Western wall however
has slight coverage from the presence of an awning.
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North Western wall
Figure G : Sun Path and shadowing of unit at 16:00 hours, September 15th
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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Sun Path Diagrams throughout the Year
March 15
th
9am March 15
th
12pm March 15
th
4pm
July 15th
9am
July 15th
12pm
July 15th
4pm
September 15th
9am
September 15th
12pm
September 15th
4pm
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Wind Analysis
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.
Wind rose diagram on site map
The Wind Rose Diagram
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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.
Wind flow around site
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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 crossventilation.
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.
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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.
LeftRight : 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 thepurpose 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
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
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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
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Cross-Ventilation
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
inlet
outlet
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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 onopposite 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.
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Material Analysis
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.
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
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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.
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 K-
Values 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 = m2K/W
R = Thermal Resistance (m2K/W)
X= Thickness of the Materials (m)
K = Thermal Conductivity of the Materials
Materials
Component Material R-Value
Walls Concrete (general) 0.12
Windows Laminated Glass 0.02
Window Frames Aluminum 0.0003
Tiles Ceramic 0.01
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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 forwindow 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.
U=1/R
SI unit = W/(m2K)
Door Plywood 0.25
Ceiling Gypsum 1.875
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
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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.
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Table 1.0 : Thermal conductivity and densities of common building materials.
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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 surfaceE= 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/m
2K4
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.
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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)
SI unit = J/K.m3
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Table 3.0 : Density, specific heat capacities and thermal conductivity of common building
materials
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Other Factors Affecting Thermal Comfort
Note: There were three occupants in the room on this day.
Note: The inhabitant was not at home on this day.
DAY 1
Time Clothing
Ensemble
Clothing Value Human Activity Metabolic Rate
(W/m2)
22:00:21 Trousers, short-sleeve shirt
0.57 Resting -Seated,quiet
60
23:00:24 Trousers, short-
sleeve shirt
0.57 Resting -
Reclining
45
0:00:27 Trousers, short-
sleeve shirt
0.57 Resting -
Reclining
45
1:00:30 Trousers, short-
sleeve shirt
0.57 Resting - Sleeping 40
2:00:33 Trousers, short-
sleeve shirt
0.57 Resting - Sleeping 40
3:00:36 Trousers, short-
sleeve shirt
0.57 Resting - Sleeping 40
4:00:40 Trousers, short-
sleeve shirt
0.57 Resting - Sleeping 40
5:00:43 Trousers, short-
sleeve shirt
0.57 Resting - Sleeping 40
6:00:46 Trousers, short-
sleeve shirt
0.57 Resting - Sleeping 40
DAY 2Time Clothing
Ensemble
Clothing Value Human Activity Metabolic Rate
(W/m2)
22:00:35 - - - -
23:00:38 - - - -
0:00:41 - - - -
1:00:45 - - - -
2:00:48 - - - -
3:00:51 - - - -
4:00:54 - - - -
5:00:57 - - - -
6:00:00 - - - -
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As there was very little variation in the clothing ensemble and activities carried out, we felt
that they do not highly affect our research.
DAY 3
Time Clothing
Ensemble
Clothing Value Human Activity Metabolic Rate
(W/m
2
)
22:00:50
Trousers, short-
sleeve shirt
0.57 House Cleaning 115-200
23:00:53
Trousers, short-
sleeve shirt
0.57 Reading, seated 60
0:00:56
Trousers, short-
sleeve shirt
0.57 Resting -
Sleeping
40
1:00:59
Trousers, short-
sleeve shirt
0.57 Resting -
Sleeping
40
2:00:02
Trousers, short-
sleeve shirt
0.57 Resting -
Sleeping
40
3:00:05
Trousers, short-
sleeve shirt
0.57 Resting -
Sleeping
40
4:00:08
Trousers, short-
sleeve shirt
0.57 Resting -
Sleeping
40
5:00:11
Trousers, short-
sleeve shirt
0.57 Resting -
Sleeping
40
6:00:00
Trousers, short-
sleeve shirt
0.57 Resting -
Sleeping
40
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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
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 m2
Area of clear floor with data logger = 7.5 m2
Natural lighting and ventilation (%) = 4.09/7.5 X 100%
= 54.5%
Figure 3.13: Area of clear floor with
data logger
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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
measured height of the chosen room is 2.8m, a clear 0.3m more than the minimum requirement.
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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 buildings 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 alack 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.
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.
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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-ACMV-
System
https://attachment.fbsbx.com/file_download.php?id=208902282617111&eid=ASu-
aRbwshg2z2p9zETyZYMX1Ci5g7HRHIzCCbqEOb25q1EEDKdxXggiKagUk2zSP68&inline=1&ext=138065827
1&hash=ASszZwdsaF3KtxaK
http://www.docstoc.com/docs/37865664/GREEN-BUILDING-INDEX-MALAYSIA-MS-1525-2007-ACMV-Systemhttp://www.docstoc.com/docs/37865664/GREEN-BUILDING-INDEX-MALAYSIA-MS-1525-2007-ACMV-Systemhttps://attachment.fbsbx.com/file_download.php?id=208902282617111&eid=ASu-aRbwshg2z2p9zETyZYMX1Ci5g7HRHIzCCbqEOb25q1EEDKdxXggiKagUk2zSP68&inline=1&ext=1380658271&hash=ASszZwdsaF3KtxaKhttps://attachment.fbsbx.com/file_download.php?id=208902282617111&eid=ASu-aRbwshg2z2p9zETyZYMX1Ci5g7HRHIzCCbqEOb25q1EEDKdxXggiKagUk2zSP68&inline=1&ext=1380658271&hash=ASszZwdsaF3KtxaKhttps://attachment.fbsbx.com/file_download.php?id=208902282617111&eid=ASu-aRbwshg2z2p9zETyZYMX1Ci5g7HRHIzCCbqEOb25q1EEDKdxXggiKagUk2zSP68&inline=1&ext=1380658271&hash=ASszZwdsaF3KtxaKhttps://attachment.fbsbx.com/file_download.php?id=208902282617111&eid=ASu-aRbwshg2z2p9zETyZYMX1Ci5g7HRHIzCCbqEOb25q1EEDKdxXggiKagUk2zSP68&inline=1&ext=1380658271&hash=ASszZwdsaF3KtxaKhttps://attachment.fbsbx.com/file_download.php?id=208902282617111&eid=ASu-aRbwshg2z2p9zETyZYMX1Ci5g7HRHIzCCbqEOb25q1EEDKdxXggiKagUk2zSP68&inline=1&ext=1380658271&hash=ASszZwdsaF3KtxaKhttps://attachment.fbsbx.com/file_download.php?id=208902282617111&eid=ASu-aRbwshg2z2p9zETyZYMX1Ci5g7HRHIzCCbqEOb25q1EEDKdxXggiKagUk2zSP68&inline=1&ext=1380658271&hash=ASszZwdsaF3KtxaKhttp://www.docstoc.com/docs/37865664/GREEN-BUILDING-INDEX-MALAYSIA-MS-1525-2007-ACMV-Systemhttp://www.docstoc.com/docs/37865664/GREEN-BUILDING-INDEX-MALAYSIA-MS-1525-2007-ACMV-System8/13/2019 Human Perception of Comfort Level BScience
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Appendix
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