Project Used.

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Name of module : Building Services 1
Module code : BLD 60304
Title : Ventilation Problem in Heritage Building
Submission Date : 23rd
November 2015
Name of lecturer : Miss Lim Tze Shwan
Name of group memebers : Mok Po Yi (0318207)
Ng Wai Khong (0317980)
Lee Ern Hui (0319703)
Hiew Li Ming (0319941)
Lim Chuning (0320369)
Lee Jian Ru (0318132)

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Introduction
Ventilation is the process of changing air to the outside as well as circulation of air
within an enclosed space. Ventilation in a building has fundamental function. The main
function of ventilation is to maintain the air purity of an enclosed space. For example,
preservation of oxygen content, removal of carbon dioxide, control of humidity, removal of
pollutant gas and etc. Ventilation system had been found out since ancient time. Back to
past, when human brought fire into his shelter, human had discovered the need to have a
opening to let oxygen in for supplying gas for the combustion and respiration while let the
smoke out. This is the basic concept of ventilation.
There are two types of ventilation which are natural ventilation and mechanical
ventilation. Natural ventilation is a ventilation system which relies on wind and thermal
buoyancy as natural driving forces. According to the history, human has already used this
driving forces to create an ideal thermal environment and remove the contaminants from the
building. Natural ventilation requires a good relationship between the building structure and
the system itself. Thus, the structure and design of heritage building is one of the influence
for the ventilation.
There are three principles of ventilations which used to utilize the natural driving forces
to ventilate a space. The principles included single-sided ventilation, cross ventilation and
stack ventilation. Firstly, single-sided ventilation (figure1.1) relies on only one side opening.
Typically, room with openable windows on one side and closed internal door has fully applied
this ventilation principle. The ventilation is promoted by the buoyancy effect depends on the
difference of temperature between the space in exterior and interior, vertical distance
between the opening as well as the area of opening. Besides, cross ventilation (figure 1.2)
allows air flows between two sides of a building. In fact, air will enter and leave through
windows, hatches or grills which intergrated in the facades. For example, open plan office
landscape. However, there is a limit to the depth of a space that can be effectively cross-
ventilated in a building. In addition, stack ventilation (figure 1.3) is drving force which
promote an outflow from the building to let fresh air enter thru openings at a lower level to
higher level. For example, building with an elevated central part, warm air rises to be
exhausted through openings such as wind tower which is located on the roof or top of the
building. Stack ventilation requires certain height between the air outlet and air inlet..

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Figure1.1 single sided ventilation Figure 1.2 cross ventilation
Figure 1.3 stack ventilation
For mechanical ventilation, it is the ventilation provided by electrical fans which oftens
be a part of air conditioning system to provide the artificial airflow supply. This kind of
ventilation required energy to generate the machines in the building. In fact, for heritage
building, mechanical ventilation might not be commonly used because the technologies has
not been modified in past and the installation fees might be high so people in past would
choose natural ventilation instead.
In this report, by studying a case study, we can find out the importance of ventilation in
a historical building and understand the traditional way to work out the ventilation system in
an enclosed space. Besides, we would study on the problems and benefits of the particular
ventilation and also way to improve the ventilation system in the heritage building while
conserving the unique part of it.

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History
There are several heritage buildings in Malaysia. In this research, we chose one of
the UNESCO World Heritage Site in George Town, Penang which is City Hall. City Hall is
municipal building in George Town, Penang and it was constructed in 1903 and opened in
1906 as the seat of Penang Government. This building is appointed as a national memorial
hall by the Antiquities Act of 1982 and as a Category 1 building.
City Hall, George Town, Penang

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Application
Natural ventilation is the process of driving in fresh air through an enclosed space by
natural means which means without the use of any mechanical system such as fans. There
are basically two types of natural ventilation system that can be utilized in a building which
are wind driven ventilation and ventilation affected by stack effect. Both of these ventilation
are affected by pressure differences which occur naturally. Wind driven ventilation caused by
pressure variations is produced by the natural forces of wind while stack ventilation is
caused by pressure generated due to differences in temperature between outdoor and
indoor of the building.
Ventilation caused by pressure variations due to wind movement occurs when the
wind blows across a building. The wind hits the windward wall to cause a positive pressure
and leave the leeward wall to cause negative pressure which is also known as suction.
Therefore, infiltration and ex-filtration air will occur. Infiltration air is the uncontrolled entry of
outdoor air into an enclosure through cracks or any openings due to pressure differences
between inside and outside where as ex-filtration air is the flow of indoor air from an
enclosure to outdoors. The air enters and leaves the enclosure through openings to provide
balance and relieves the pressure on the walls.
In this wind driven ventilation system, to provide ventilation and capture the wind, the
shape of the building acts as an important factor. The shape of a building helps in creating
wind pressure that can drive the air flow through openings provided in the building such as
windows and doors. Moreover, there are many other factors that plays a big role in design
guidelines for different buildings. For example, to maximize the ventilation, location with a lot
of wind should be chosen so that the windward wall is perpendicular to the wind.

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Besides, Infiltration and ex-filtration can occur when there is difference in temperature
caused by weather. Infiltration usually occurs mainly during winter as the air outside is
colder. Colder air is heavier than the air outside which is hotter and less dense. In high-rise
buildings the stack effect also causes infiltration where the outdoor air enters the enclosed
building or space. In contrast, ex-filtration occurs during summer where the flow of indoor air
from a building to the outdoors. In summer, the air outside is hotter while the air inside in
colder. Therefore, the direction of natural air flow is from the inside to outside since the air
inside is colder and much denser.
One of the factor which causes ventilation is the stack effect of warm air rising within
a building, while cooler air exists outside replaces it. Stack ventilation is affected by the
difference between the temperature. In this ventilation system, warm air is less dense while
cool air is denser, therefore warm air in the building rises, the cooler air enters from any
openings below and replaces the warm air.

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Other than that, there is also another system known as Passive Stack Ventilation
(PSV). This system involves the combination of the air flowing over the roof and the natural
buoyancy of warm air to lift up the moist air from the kitchen, bathroom and others to the roof
ridge level where the air escapes into the atmosphere and then fresh air enters into the
building through trickle vents or passages in the windows and doors to replace it. PSV
system is energy efficient therefore it can work without the need for any electrical fans or
control. The ventilation depends on the amount of movement of external air and
temperature. Both wind and stack driven ventilation is important as a natural ventilation
system, design for natural ventilation should therefore incorporate to maximize design
concepts of both for better air flow and energy efficient system.

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Installation
Over a century of history, Penang City Hall which located at Georgetown had applied
the basic natural ventilation system to cope with the weather of Malaysia which is always in
a state of hot, humid and rainy condition. Unlike countries which undergoes four seasons,
the City Hall which is built in Malaysia takes the least concern for Infiltration Air and
Exfiltration Air in both internal and external of the building over the year. Moreover,
Georgetown, Penang is located on an island which also approved the needs for natural
ventilation which is affected by pressure variation due to wind and stack effects.
While, for the natural ventilation to be more effective, there must be adequate of
ventilation at every divisions and rooms in the particular building although the wind doesn’t
prevail to any of the direction surrounding the buildings. As in the diagram above, openings
like doors, windows and small air window is installed at every faces of direction of the
building. Hence, the building was placed on an urban space or land where the inlets and
outlets of the building are not obstructed by any object which will effects the wind to flow into
the building. Furthermore, vertical shafts and open staircases were installed in advance to
generate stack effects.

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Beside the hall inside the building, all the divisions and rooms are installed and
designated narrowly to allow natural ventilation to be effective, because it is difficult to
distribute fresh and healthy air to every portion of the buildings if the space of each particular
room is wide by using natural ventilation. Mostly of the rooms have more than 2 or more
separated supply and exhaust openings, the windows openings must be operable by the
occupants, so that the ventilation can be effective.
When the wind or air flow into the building, it will creates a recycle, refresh and
rejuvenate in the process of maintain the ventilation inside the building always fresh and
establish hazard-free internal air quality. Openings will be installed at the top of the buildings
or roofs to circulate the air from the inside to the outside in the process of Infiltration and
Exfiltration of Air. This is crucial due to the different temperature of surrounding in the
morning and night time. So, the requirement of the ventilation in the building should be
balance in terms of temperature no matter in the morning or night time.
Installing opening above the door takes an important role for wind and stack effect to
be more productive because the doors located at the outside will not be opened 24 hours in
terms of security and safety for the building. Hence, the help of the opening above the door
ensures fresh air to enter the building without the usage of the doors. Based on the diagram,
the door should be left opened at the outside during day time and door placed indoor should
be opened to receive fully circulate air for the whole building regarding the rooms and
division.
An open-building approach works well in warm and humid areas especially in
Malaysia, because the temperature doesn’t change much in the daytime and nighttime.
Therefore, daytime cross-ventilation is encourage to maintain the indoor air quality and
temperature equivalent to the outdoor temperature.

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Advantages and Disadvantages
There are two types of ventilation system found in City Hall, Penang which are
mechanical ventilation such as fans and air conditioners and natural ventilation which are the
openings of a building. As everything is in the world, there are advantages and
disadvantages for both type of ventilation system.
First and foremost, my group has decided to look into mechanical ventilators. City
Hall, Penang possess two types of mechanical ventilators which are fans and air
conditioners. For starters, there are several advantages for using a fan on a day to day basis
as City Hall is now an office building. One of the main advantage of having a fan as a
mechanical ventilator is that ceiling fans can keep the people in the room cool. A ceiling fan
pushes air downwards which helps create a breeze that helps the person to cool their skin
through evaporation, this can keep the workers who are using City Hall as an office to stay
cool twenty four hours a day. Besides that, unlike the air conditioner, a ceiling fan does not
use a lot of electrical energy hence, it saves money and energy. A ceiling fan requires the
same amount of energy to function as needed by a standard 100W light bulb. Strategically
locating a ceiling can provide ample amount of cool air to a room which can reduce the
usage of air conditioners which in turn can save large amount of energy.
The disadvantage of ceiling fans are that they are noisy at times. This usually
happens when the rotators lose the greasiness which will cause an unpleasant sound. This
will create an unsettling environment especially for a work place which should be peaceful
and calm. This means rotatory maintenance is needed for fans. In addition, ceiling fans are
difficult to clean as you are required to climb up a ladder to clean it. If the fan is not cleaned
regularly, layers of mould and dust will be formed on the blades of the fan which will cause
some discomfort if used. In this case, this disadvantage will be emphasized on as the ceiling
fans were not properly cleaned for the office use (refer to figure 3)
Secondly, the other mechanical ventilators present in the building is an air
conditioner. The advantage of using an air conditioner is that it creates a very clean and
germ free atmosphere. This is because air conditioners are capable of filtering out pollen,
dusts and allergens which could cause discomfort in the room. This is very useful if it is used
in an office building such as City Hall, Penang as it can disinfect the air we breathe which
creates a friendly environment especially for workers who have asthma. As for the
disadvantage of using air conditioning, it is very costly and hazardous to the environment. It

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is expensive to use the air conditioner as it uses a lot of electricity. Since it uses so much
electricity, large amount of coal has to be burnt to produce more energy to power the device
which causes a large production of carbon dioxide which promotes the greenhouse gases
which leads to global warming.
Last but not least, natural ventilators are found in City Hall as well which are the
opening found in the building such as windows and doors. The advantage of natural
ventilators is that they are lower in cost. It is cost free because natural ventilation relies on
wind to provide the cool air into the building. Since it dependant on the movement of the
wind, it can help replenish fresh air into the building which can improve the air quality in the
building. The disadvantage of natural ventilation is that it is unsuitable for noisy and
clustered areas. This is because noise will enter the building through the openings which will
cause disruption in the quiet environment of a place. It is also not suitable for places which
are clustered which is strongly related to our case study regarding City Hall as we
discovered that there are the presence of obstructing objects around the openings the
building which disrupts the flow of wind or fresh air into the building . This is major problem
as it does not make the natural ventilation as effective as it should be.
In conclusion, both type of ventilation system brings their own set of pros and
cons. Which is why most people require both type of ventilation system as the 2 different
ventilation system complements each other but both carry the same purpose and that is too
provide a cool and allergen free environment for the user.

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Ventilation Problems in City Hall
City Hall is located at the north end of Penang Island. It is located by the sea and
results in the effect of ground water level and salinity. These conditions occur the cause of
deterioration in heritage building due to uncontrolled moisture problem. If untreated, it can
led to dampness, rotting, molding and destruction of materials, finishes and building
structures. Besides that, the growth of fungi and other microbial agents due to uncontrolled
moisture will degrade the indoor air quality.
Figure 1
Besides the moisture problem, salt crystallization also contributes to the freshness of
indoor air quality. Salt weathering is related to moisture problem. It results in the breakdown
of surface materials such as concrete. Different building materials have different salinity
values. Modern porous building materials such as Portland cement contained a high content
of salinity value which is sodium chloride. The salt that remains on the surface of concrete
wall leads to the occurrence of salt weathering after the moisture is evaporated. After time,
materials decay by abrasion, erosion, crumbling and loss of the surface.
Figure 2

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Another pollutant is dust. Dust Mites are a species that prefer warm and humid
climate. Dust is generally found on the floor, corner or other surfaces. For this building, we
found that it is mostly accumulated in the mechanical ventilation system such as air
conditioner diffusers and fan and architectural structures such as cornices. When a person
inhales too much of dust, the enzymes that contained in dust can kill cells within the human
body. It is not only degrade the indoor air quality, it will also affect one’s health.
Figure 3

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Recommendations
After conducting our research on Town Hall, Penang, we have discovered that the
ventilation system as well as air quality in this heritage building was deemed unacceptable
and we then furthered our research to pinpoint the problems that causes the poor indoor air
quality and we have made several recommendation to improve the ventilation system in this
building.
First and foremost, one of the main problem discovered which caused the building to
have poor air quality is due to the fact the mechanical ventilation systems were not properly
cleaned nor maintained throughout its’ reuse as an office building as observed from diagram
1 and 2. Therefore, one of the methods to improve the air quality in Town Hall, Penang is by
giving regular maintenance for the mechanical ventilation present in this building. The
pictures gathered on the mechanical ventilation in Town Hall, Penang proves that they did
not clean the fans and the air conditioners for a period of time as layers of dust and mould
have already been laid on the fans and air conditioners. Hence, to improve the ventilation in
Town Hall, Penang, the mechanical ventilators should be regularly cleaned to allow the
ventilators to operate smoothly and efficiently.
Diagram (1) and (2)
Besides that, my group noticed the presence of local obstructing objects preventing
the wind from entering into the building. This sort of circumstances will reduce the natural
ventilation of a building as fresh air cannot properly enter the opening of the building. It was
observed that the buildings and trees located nearby this heritage building have blocked the
path of the prevailing wind direction. To overcome this predicament, we suggest to build
include architectural elements such as wingwall or parapets which can help redirect the
direction of the prevailing wind into the openings. This can not only help improve the
ventilation but it can help save the cost of the building. This is because they do not have to
rely solely on the mechanical ventilators as much if the natural ventilation of this building
improves.

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Furthermore, this heritage building has been reused as an office building. Like every
other office buildings, there are the presence of machines such as computers and printing
machines which increases the temperature of the building and emits harmful chemicals to
the office workers. In addition, the building has a high percentage of humidity and moisture,
this means that the restrooms are not properly ventilated which can cause the environment
of the building to feel uncomfortable. Exhaust Ventilation system should be install in this
building to overcome this problem. The function of exhaust ventilation system is to ventilate
the harmful fumes, excess heat and moisture content from the building. The target areas for
these exhaust ventilators are to be placed at the printing room which emits harmful gases
such as ozone and generates large amount of heat and as well as the wet rooms such as
restrooms found in the building. With the presence of the exhaust ventilators nearby these
areas, the air quality of the building will drastically improve as the unwanted chemicals and
bacteria in the air will be quickly removed and will be replaced with fresh air.
Last but not least, solar chimneys should be installed in this building to improve the
natural ventilation of the building. A solar chimney carries the function of regular chimney but
is powered by solar energy. The solar chimney will increase the heat of the air on top of the
roof. This will cause the hot air to exit the building due to the pressure difference and the
cold air below it will rush in to take its’ place and the process is repeated. This greatly
improves the natural ventilation of the building and helps replenish the indoor air which can
help remove harmful bacteria and dust from the surrounding environment. Diagram 3 shows
an example of how a solar chimney works when installed into a building.
Diagram (3)
In a nutshell, these are one of the few recommendations to improve the ventilation
system in Town Hall, Penang with hope that these recommendations can improve the air
quality of this heritage building to ensure that this building can be reused and preserved for
many years to come.

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Conclusion
In the nutshell, ventilation for a particular building is keen important in preserving the thermal
comfort, healthy and fresh recycle of air quality in the indoor of a building and available the building to be
more sustainable. Both natural and mechanial ventilation works as a chemistry together to strengthen
and improve the indoor air quality of the heritage building, so the building can be preserved, used as an
economical profit to the country (tourist spot) and to bring down another few hundred years for the future
generations because these heritage buildings symbolize an occurance happened on the past like our
building were once built by the British when we are under control by Britain in the 90’s.
Through the case studies we examined, observed and investigate, it doesn’t only tell us about how
important the ventilation is, the factors and also the effects of both natural and mechanical ventilation. It
also teaches us on how to apply these ventilation system to our own building and how to advise people
on installing these mechanical ventilations in their respective building because these knowledge will bring
us and assist us especially after we graduated and enroll in the construction field. Hence, in the future,
we will be able to be assign and handle with more task and job which are related to ventilation.
Furthermore, our group mates had contributed each topic in order to complete this report. By using
the knowledge that the lecturer taught in class about ventilation and also a bit of finding in the library and
referencing through online, we are able to present a completely filled report of our topic. This required
good co-operation between group mates and also appreciate the guidance, ideas and opinions
contributed by our class lecturer to avoid putting false information and knowledge about ventilation in this
report.

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Citation
1.) Prihatmanti, R., & Bahauddin, A. (2014). Retrieved October 16, 2015, from
http://web.usm.my/jcdc/vol19_1_2014/JCDC 19(1) 2014-Art. 5 (69-91).pdf
2.) Natural Ventilation Explained. (2010). Retrieved October 19, 2015, from
http://www.breathingbuildings.com/products/natural-ventilation-explained
3.) Walker, A. (2014, April 11). Natural Ventilation. Retrieved October 19, 2015, from
https://www.wbdg.org/resources/naturalventilation.php
4.) Mechanical Ventilation. (n.d.). Retrieved October 21, 2015, from http://new-
learn.info/packages/clear/thermal/buildings/active_systems/mv/index.html