UNIVERSITI TEKNOLOGI MARAUITM SHAH ALAM

Faculty of Architecture, Planning & Surveying

BUILDING SERVICES III( QSM 605 )

VENTILATION system-natural ventilation

-Mechanical ventilation

PREPARED BY:

NAMA MATRIC NO.

1. FATHILL HANIFF B. AHMAD TAJUDDIN 2009889178

2. M.IKHWAN B. SAEDON 2008413444

3. NORANIZA BT SAFIEE 2008413452

4. SITI HAWA BT ABD RASHID 2008424238

5. NOR ‘IZZATI BT MD. ZAINI 2008413436

6. SITI FATIMAH BT MUHAMAD 2009652852

7. NURUL AIN BT MOHD ISA 2009662636

8. ASMA’ BT MOHD BADRAI 2009427736

9. JUHANA BINTI IDRIS 2009232416

10. NURHAYATI BT ABDULLAH SUHAIMI 2009871856

11. NURUL NADIAH BT ABDUL MALIK 2009674704

CIK NUR HIDAYAH BINTI IDRIS

BACHELOR IN QUANTITY SURVEYING (AP224) – 5E

PREPARED FOR:

VENTILATION SYSTEM

The process by which fresh air is introduced and contaminated air is removed from an occupied space.

Ventilation is the circulation of fresh air in an enclosed space.

For example a room whilst driving out ‘four’ or ‘stale’ air from the same space.

Good ventilation is required in an building for health purposes.

PURPOSE OF VENTILATION

Ventilation is required for one or more of the following purposes:

a) Provision of outside air for breathing;

b) Control of excess humidity (arising from water vapour in the indoor air);

c) To provide a continuous supply of oxygen necessary for human existence.

d) To remove the products of respiration and occupation

FACTORS TO BE CONSIDERED IN DESIGNING VENTILATION

To design a ventilation system, the engineer has to meet two basic requirement :

1) To supply fresh air for the occupants.

2) To change the air in the room sufficiently Smells, fumes and contaminants are removed. Excess heat Food and body odours Water vapour and carbon dioxide

natural

system

INTRODUCTION

Uncontrolled air movement into a home through cracks, small holes, and vents such as windows and doors

Ventilation without the assistance of fans or other mechanical air moving equipment and uses no energy

Used to be the most common ventilation method of allowing fresh outdoor air to replace indoor air in a home or the building.

APPLICATION OF NATURAL VENTILATION

Among the primary types of buildings that can benefit from the application of natural ventilation are:

bus stations, picnic shelters, and other structures where stringent space conditioning is not expected,

barracks and other single- and multi-family housing projects,

most small, free-standing structures in warm and temperate climates, and

maintenance pools, and other high-bay facilities in warm climates

Factor Affecting Natural Air Movement Around and Within Building.

1) The site and local landscaping features

2) The building form and building envelope design

3) The internal planning and room design.

4) Water features and vegetation

Agents of Natural Ventilation

Stack effect is a natural phenomenon of air movement driven by the difference in air density between the exterior and the interior of a building. It is also referred to as the "chimney effect", and helps drive natural ventilation and infiltration.

1.STACK EFFECT

The stack-effect, as briefly mentioned above, is based on the fact

that warmer air rises as cooler air falls. This is due to differing densities;

when air is heated, it becomes less dense, allowing it to rise, pushing cooler

air downwards. Creating an upward air stream, this concept is very important

in the stack-driven method of ventilation.

Figure 1: Natural forces of wind pressure to create areas of high and low

pressure around a house

1.STACK EFFECT (CONT’D)

ADVANTAGES & DISADVANTAGESOF STACK EFFECT

ADVANTAGES DISADVANTAGES

Does not require wind; can work even when the surrounding air is completely still.

Cannot control exterior temperature

Relies on natural force (pressure and temperature differences)

Can bring polluted air into buildings

More control with regards to where the openings in the building are

-

Uses almost no energy compared to conventional methods, saving money and the environment.

-

1.STACK EFFECT (CONT’D)

2.WIND EFFECT

When wind collides with a building, different pressures are observed from

different sides of the building. The side that the wind is blowing into would have a higher

air pressure than the opposite side; this would cause the air on the side with the higher

pressure to flow to an area of lower pressure, which in this case would be the building’s

interior. Another opening on the low pressure side would allow the interior air to circulate

outwards to the side with the lower air pressure

Figure 2: The wind comes

from the left (high pressure),

flows through the building,

and flows out into the low

pressure area (at the skylight

on the other side of the

building). This combines

wind-driven and stack-driven

ventilation.

ADVANTAGES & DISADVANTAGESNATURAL VENTILATION

ADVANTAGES DISADVANTAGES

• Does not require energy • Lack of control

• Lower costs • More difficult to predict, analyze and design

• Safety • Potential for noise intrusion

• Efficient method of ventilation • Shares some of the limitations

• Does not require sophisticated analytical equipment

• Negative pressure in isolation areas

Case study 1

Residential Tuan Haji Che Noor Azeman Che Yusuff

Figure 3: doors and windows as natural ventilation

MECHANICAL

VENTILATION..

Used for applications where natural ventilation is not appropriate.

Employ an electrically fan to provide the necessary air movement

Ensure a specified air change and the air under fan pressure can

be forced through filters

Circulate fresh air using ducts and fans, rather than relying on

airflow through small holes or cracks in a home’s walls, roof, or

windows.

The AIM : To induce the necessary air change without

discomfort.

INTRODUCTION

Why we used Mechanical Ventilation?

1. Internal rooms

2. Large closely populated rooms usually more than 50 people such as in Shopping complex,

office, hall etc.

3. Where close control of environment is required .E.g. hospital

4. Where natural ventilation is impossible as windows cannot be opened because of external

atmospheric population or noise especially near to industrial areas.

5. In tall building where wind and stack effects would render natural ventilation impracticable.

Figure 4: KLCC (source :Google image)

6. Extract ventilation to deal with fumes, smells and odors

7. Heat liberation within the room (i.e. cooking)

8. Moisture liberation within the room (steam) - i.e. bathroom

9. Replacement of air extracted by industrial process

10. High heat or moisture gain from outside

11. To maintain a clean atmosphere or to alleviate noise from outside etc.

Why we used Mechanical Ventilation? (cont’d)

Characteristics Of An Ideal Mechanical Ventilation Sys.

1.Not interfere with the building

envelope.

4.Distribute outdoor air

where needed.

6.Be quiet.

5.Not interfere with other systems.

3.Provide needed amount of air exchange

2.Operated when only needed

IDEAL IF…

Method of mechanical ventilation

3. Mechanical

inlet and outlet

2. Mechanical outlet

with natural inlet

1. Mechanical Inlet Natural Outlet

Air is blown into the building through a fan convector or ducted system

The air leaks out of the building through adventitious openings and permanent air bricks or louvers.

The process:

A single room, perhaps an office, might have an outside air supply

from some form of reversible fan unit

Can be used for factories, large public halls or underground

boiler plant rooms.

1. Mechanical Inlet Natural Outlet (cont’d)

2.Mechanical Extract With Natural Inlet

Mechanical extract fans in windows or roofs and

ducted systems where the air is to be discharged

away from the occupied space owing to its

contamination with heat, fumes, smoke, water

vapour, or odour.

This system can be used in dwellings, offices,

factories, or public buildings.

A slight reduction in air static pressure is caused

within the building, and external air flows

inwards. This inflow is facilitated by air inlet

grilles, sometimes situated behind radiators or

convector heaters.

There is no filtration of incoming impurities. This

system is used particularly for toilet or kitchen

extraction, smoke removal from public rooms and

heat or fume removal from industrial premises.

FUNCTIONS OF MECHANICAL EXTRACT

Irrespective of wind and

temperature difference and will be

positive in action.

Since the air to be extracted from

the space provided for admission

of outside air will present some

resistance to flow, leakage inward

from surrounding spaces is more

likely than leakage outward.

Escape of steam, fumes and

noxious vapours generated within

the ventilated space is less likely

than would be the case if reliance

were placed upon natural extract

alone.

A specific area where local authority requirements

bear upon the provision of mechanical extract

with natural inlet relates to internal toilets and

bathrooms, particularly in multi-storey housing.

The principal conclusion being that a ventilation

volume of 5.5 litre/s should be provided for each

fixture, inlets may connect to a rising shaft with,

perhaps, some form of heater at the base.

Subject to decision by the fire authority, it may be

possible to use the shaft provided for rising water

pipes for ductwork if space be allocated also to

wastes from sanitary fittings. Some authorities

require that a lobby be introduced at the entrance

to toilets in public buildings and that this be

provided with a supply of outside air by an inlet

plant serving no other duty.

BASIC REQUIREMENTS

PROCESS OF VENTILATION

1. Uses extractor fans. A fan will create a negative

pressure within the space.

2. Set flow rate can be achieved, as the fan will

overcome the stack and wind effects; hence, the

system is hot at the mercy of the weather.

3. This system causes the inside of the buildings to be

held at a negative pressure, so air will be drawn in

from outside or from surrounding spaces that are at

a high pressure.

4. A space may need to be held at negative pressure,

as in lavatories, kitchens, and process areas for

example, in such cases, air will flow into the

negative pressure zone, hence, odors or toxic gases

will not escape to other areas.

5. This fan, with its running and maintenance costs,

makes this system more expensive than the natural

method.

DESIGN CONSIDERATION

Designed to filter and recirculate much of the

conditioned air, certain percentage of outdoor air

along with the recirculated air. Where exhausting

of air is required, ventilation systems must

exhaust directly to the outsides; none of the

exhausted air can be recirculated.

A toilet room exhaust fan, will be connected to a

duct that leads to the exterior without connecting

in any way to the building’s ventilating system.

Local building codes should always be referenced.

Typical examples of the number of air changes per

hour are:

office floor 2-6

classrooms 3-4

restaurants 10-15

kitchens 20-40

public places such as auditoria and dance halls,

are often measured in terms of the number of

occupants to be served.

THE SUPPLY OF AIR INLET

Air must be supplied to a building under emergency

fire conditions to make good the air extracted

through inlet openings without the use of fans.

The air supplied must be beneath the level of the

smoke layer and at a low velocity in order to avoid

disturbing the smoke above.

With natural exhaust ventilation the inlet areas

must be from 1.5 to 2.0 times the exhaust areas but

this is not so important with mechanical extract.

With fan-powered extract, the face velocity over the

inlets should be about 3 m/s and should never

exceed 5 m/s.

Inlets may take the form of doors that fail to the

open position in an emergency, automatic louvers in

the walls or the roof interlocked to open when the

smoke exhaust fans are energised, roof vents in

adjacent smoke reservoirs that are interlocked to

stay shut if the reservoir is smoke logged, and inlet

fans.

VENTILATION OF INTERNAL WCs AND BATHROOMS

To maximize the use of space. It is necessary to provide

means of extract ventilation to internal bathrooms and

WCs, to dilute pollutants and moisture vapour in the air

by air changes.

Extract ventilation may be provided by mechanical

extract of air or by passive stack ventilation. Passive

stack ventilation as a ventilation system that uses ducts

from the ceilings of rooms to terminals on the roof to

operate through the natural stack effect of warm air

rising, as in a chimney stack.

The Building Regulations recommend the extract fan

should be controlled by the operation of the light switch

to the room and have a 15 minutes overrun after the

light is turned off. There should be a 10mm gap under

the door to bathrooms and sanitary accommodation,

through which replacement air can enter.

3. MECHANICAL INLET AND EXTRACT

The system to extract and inlet using the mechanical

equipment.

Used when a building is to be seated from the external

environment like cinemas, offices, restaurants, department

stores etc.

Supply Air

Return Air

Supply Fan

Extract Fan

ROOMROOM

The system is the best system amongst the system to create the internal

environment required

The enclosed space must be sealed for efficiency

In a foreign country, especially in winter, cold outside air may cause discomfort so

the fresh air is heated. Heater battery

Air filter

Warm Supply Air

Return Air

Supply Fan

Extract Fan

3. MECHANICAL INLET AND EXTRACT (CONT’D)

In most balanced systems, the supply air quantity, which is required, work

out to be much more than needed for fresh air supply to occupant

It is possible to re-circulate some of the extract some of the extract air back

into the supply duct.

Air filter

Warm Supply Air

Supply Air

Return Air

Supply Fan

Extract Fan

Damper

Heater battery

3. MECHANICAL INLET AND EXTRACT (CONT’D)

DEVICE OR COMPONENT OF MECHANICAL VENTiLATION

1. FAN

2. FILTER

3. DUCTWORK N FIRE DAMPER

4. DIFFUSER

1. FAN

INTRODUCTION

Devices to move air.

Sometimes called air pumps or blowers.

Without fans these are no mechanical ventilation.

Installed in openings in the walls, in cooker hoods or in an air-conditioning

system (AHU room).

Type:

a. Propeller fan

b. Axial fan

c. Centrifugal fan

Axial fan and centrifugal fan used in heavy duty.

Propeller fan is found in most of the wall mounted ventilation fan units

INTRODUCTION (cont’d)

Fans move the air either

a. from the outside to the inside (intake fans or supply fans)

b. from the inside to the outside (intake fans or supply fans)

c. from the inside to the outside (extract fans or exhaust

fans).

Ventilation fans are required by law for toilets which do not have a

direct opening to the outside air.

Turbine fans located at the roof ventilate the roof loft to help keep

the building interiors below cool.

1. Propeller fan

2 or more blades fixed at an angle to the hub.

Free standing use as ordinary fan.

Domestically applied to voids in kitchen and bathroom

wall.

air opening wall or window but short length of ducting

maybe used.

A propeller fan having broad curved blade will move more

air and is quieter than a fan with narrow blades of the

same diameter and running at the same speed.

1. Propeller fan (cont’d)

2. Axial Fans

Impellers with blades mounted and rotating on a motor

driven central shaft

located in a cylindrical casing to adaptation to ductwork.

Aerofoil blades can be used to increase efficiency.

It is a high pressure fan.

Larger versions have belt-driven impeller from an external

motor.

Some of the fan has insulated with housing to protect the

fan-cooled motor .

There have two type of axial fan type such as Tube Axial

and Vane Axial.

Variable pitch, field adjustable impellers maximize performance, minimize horsepower requirements, help reduce operating costs

T-shaped motor mounting bases accept readily obtainable, standard foot-mounted motors

Fans mount in any position – horizontally, vertically, and angularly – in or out of the duct system

Cast aluminum axial flow impellers can’t spark and use improved airfoil sections for maximum air handling efficiency

Spinner cap improves laminar flow of inlet air

Streamlined design helps keep fan housing to minimum depths for low silhouettes

Sealed ball bearing motor provides years dependable, maintenance free performance.

Tube axial duct fans

2. Axial Fans (cont’d)

Belt tension is maintained by simple adjustment of motor base height on threaded support

Streamlined belt drive fairing keeps friction and entrance losses to minimum

Spinner cap (not shown) improves laminar flow of inlet air

Variable pitch, field adjustable impellers maximize performance, minimize horsepower requirements, help reduce operating costs

Cast aluminum axial flow impellers can’t spark, use improved airfoil sections for maximum air handling efficiency

Welded housing protects bearing sand drive from fumes, corrosives, caustic

Flanged housings permit quick fastening to flexible duct and other accessories without special tools or skills

Fast, simple bearing, belt or pulley changes can be accomplished by one person without special tools

Vane axial fans with belt drive motors

2. Axial Fans (cont’d)

3. Centrifugal Fan

consist of an impeller rotating revolves inside the casing shaped like a

scroll.

Air is drawn in at right angles before discharging radially under centrifugal

force through the delivery ductwork.

The inlet of the fan is at 900 to the outlet and this make it sometimes

difficult to install unless the ductwork can also be turn through the same

angles.

The small fans have an integral motor mounted centrally within the

impeller but larger models associated with high pressure and long

deliveries have an external motor and pulley block system of gearing.

a. The impeller blades can be

b. forward (a),

c. backward (b) paddle blades (c).

Centrifugal fan are more favourable for larger installations.

3. Centrifugal Fan (cont’d)

3. Centrifugal Fan (cont’d)

Forward-curved blades

use blades that curve in the direction of the fan wheel's rotation.

The forward blade is best suited to low and medium constant pressure, as a high system

resistance could overload the fan with this impeller.

Backward-curved blades

use blades that curve against the direction of the fan wheel's rotation.

used in fans designed to handle gas streams with low to moderate particulate loadings.

They can be easily fitted with wear protection but certain blade curvatures can be prone to

solids build-up.

Apply to high and variable resistances, such as that found in high-velocity ventilation

system.

much more energy efficient than radial blade fans

Straight radial blades

extend straight out from the hub. 

Paddles or flat blades suited for air having a high level of suspended matter, dusty or dirty.

It is often characterized by greater noise output.

3. Centrifugal Fan (cont’d)

COMPARISON BETWEEN

PROPELLER, AXIAL &

CENTRIFUNGAL FAN

Element /Type Propeller Fan Centrifugal fan Axial Fan

Blades feature More than 2 blades fixed at an angle to the hub.

A propeller fan comprises several steel or plastic blades.

An impeller rotating revolves inside the casing shaped like a scroll.

The impeller blades can be: forward backward paddle blades

Impellers with blades mounted and rotating on a motor driven central shaft, located in a cylindrical casing to adaptation to ductwork.

Pressure and efficiency

Pressure of only about 125 pa.

Efficiency les than 40 per cent.

High pressure of up to about 760 p.a .

efficiencies range from 45 to 85 per cent

Efficiencies up to 75 per cent Pressure up to 700pa.

Application Most applied domestically to voids in kitchen, bathroom and workshop wall.

Large building used in the length of the ductwork basement

Advantages Can remove large volumes of air. Installation comparatively easy and cheap.

Move more air and it quieter.

quiet in operation favorable for larger installations

Ease of installation connected to flange at either end of the fan.

Disadvantages Unsuited to ducted system.

It required some maintenance.

More plant room space is needed Bulky

2. FILTER

used and design into gas or air flow systems to remove

particulates from the air flow to what is termed as ‘air

conditioning’.

simple technique of removing and preventing air born

particles from clogging heating or cooling fans or

radiators to a small as 0.1 micron which could cause

significant performance degradation in the air flow

system as well as damage the heat exchanger system.

INTRODUCTION

Purposes of filtrating the air:

Improving the occupants’ breathable environment.

Protecting facilities like walls, ceiling and equipment from air born particle damage.

Protecting the contents of occupied building spaces such as items of artistic historic

or cultural value.

Elimination or minimizing fire hazards

Improving shelf life of perishable food products by removing airborne mold

Removing airborne bacteria from controlled environment such operating rooms

Filtering or removing air born particulates which could damage sensitive micro

electronic device within clean rooms

Type of Filter:

Dry filter Various filter Electrostatic filter Activated Carbon filter

DRY FILTER

Be produced from paper, fine woven fabrics,

foamed plastics or glass fiber

Fit into a purpose-made compartment at the air

intake.

Dry filter normally used in air conditioning, paint

booth, compressor air intake, paint booth and

ventilation systems.

Dry Filter (cont’d)

VISCOUS FILTERS

defined as an air-cleaning filter having a surface coated

with a viscous liquid to trap particulates in the airstream.

The whole unit is supported on a steel framework.

extensively used for air conditioning and general

ventilation purposes in high dust concentration(capable

of handling high volume of air)

Various types of viscous filter

ELECTROSTATIC FILTER

Electrostatic air filters contain synthetic fibers that create a

static electric charge to attract particulates.

This static charge attracts and traps airborne particles into

the filter just like a magnet.

Reusable filters can be washed with a garden hose several

times before replacing.

very efficient as it removes up to 95.3% of airborne

particles

Microscopic View and Example

Clean Filter

Dirty Filter

Advantages

Benefit the environment because they are

reusable.

Remove a high percentage of airborne

particles.

will last for a long time, and is easy to install

and maintain

ACTIVATED CARBON FILTER

also known by the terms “activated charcoal” or “activated coal

designed and used for the removal of vapors and odors which

still may be present within the air or gas flow

has an extremely large surface area for the chemical

reactions.

The reason for a large surface area of carbon filter is to attract

and clean large amount of air which comes into contact with it.

ACTIVATED CARBON FILTER

Compared with air fresheners which are sprayed or mounted

near windows or other areas in the house, activated carbon

air filters are far better and efficient in cleaning the air.

carbon filters can as the latter works by capturing the gas

molecules which are the cause of foul odors

A relatively small amount of activated carbon is sufficient in

filtering or cleaning the air of the entire house.

Example of Activated Carbon Filter:

3. DUCTWORK & FIRE DAMPER

Fire Dampers are passive fire protection system designed to close when temperatures rise in order to stop the spread fire

Fire Dampers are used to prevent transmission of flame where air ducts penetrate fire barriers.

Fire Barrier is a fire-resistant, vertical or horizontal assembly of materials designed to restrict the spread of fire in which openings are protected

INTRODUCTION

Fire dampers to prevent the spread of fire and/or smoke inside the ductwork where the ductwork penetrates fire-resistance rated walls and floors. Fire dampers are installed by inside the ducting.

When a rise in temperature occurs, a fire damper will close and prevent the spread of flame through the barrier. Dampers are typically curtain style that will close (shut) when a fusible link melts.

Fire dampers are passive fire protection products used in

1. air conditioning

2. ventilation ductwork

INTRODUCTION (cont’d)

Fire Damper

DUCT

Materials used in the production of spiral

duct:

Galvanized Galvaneal or "paint grip" Aluminum Stainless Steel PCD coated

Diameters produced: 4" to 100" capabilities

Designing an inflatable duct system

Designing an Active inflatable duct system is straight forward providing

the following basic rules are adhered to:

Perforated ducts should be as short as possible- ideally 50 to 80

feet (15 - 24 meters) and never longer than 100 feet (30 meters).The

installation ducts up to 150ft but cannot promise for their performance.

Ducts should be straight - Avoid unnecessary elbows etc.

Keep the design simple - Use as few ‘tee-pieces’ , ‘y-pieces’, splitters

etc. as possible

Use flow straighteners - after fans, elbows, etc

Maximum inflatable duct lengths

Plain ducts - To convey air from point to point -

maximum 300ft. (91m)

Perforated ducts - To distribute air.

Optimum 50 to 80 feet (15 - 24 meters)

Maximum 100ft. (30.5m).

Ducts from 100ft (30.5m). up to 150ft. (45.7m), can be

manufactured, however the lateral temperature control

suffers.

Component of duct

4. DIFFUSER

defined as an air distribution outlet, typically located in the ceiling,

which mixes conditioned air with room air.

the supply air, consisting of both fresh and re-circulated air, must

reach all occupied areas of the building.

There are several reasons of applying diffuser:

To deliver both conditioning and ventilating air.

Evenly distribute the flow of air, in the desired directions flow pattern

around it.

producing the minimum amount of noise

To create low-velocity air movement in the occupied portion of room

INTRODUCTION

Three basic type of diffuser airflow pattern

Symmetric non-spreading

Spreading Double plume non-spreading

The effect of plume are called coanda and it crated by

restricted air and pressure at the adjacent surface due to

limited access for air to replace the entrained air above

the plume.

Secondary air into the plume is call entrainment.

Installation economy and as means of evenly distributing

air, suspended ceiling and raised floor can be used as

plenum chamber

Coanda effect Plenum ceilling

ADVANTAGES AND DISADVANTAGES OF

MECHANICAL VENTILATION

2.More Control.-provide proper fresh air flow along with appropriate locations for intake and exhaust.

4.Improved Comfort-allow a constant flow of outside air into the room and can also provide filtration, dehumidification, and conditioning of the incoming outside air.

3.Control air flow- The airflow rate and distribution can be controlled precisely during all weather conditions

ADVANTAGES

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DISADVANTAGES

NATURAL VS MECHANICALDIFFERENCES NATURAL VENTILATION MECHANICAL VENTILATION

Suitability Suitable for warm and temperate

climates mean moderately useful

with natural ventilation possible

50% of the time.

Suitable for all climates and weather with

air-conditioning as climate dictates.

Cost Capital costs for a naturally

ventilated building 10–15%

lower than air-conditioned

equivalents

Expensive because of the higher cost for

operable windows and interlocking controls

for the HVAC system.

Operate Lower capital, operational and

maintenance costs for simple

natural ventilation.

More controlled and comfortable

environment.

Installation and

maintenance cost

The maintenance cost of simple

natural ventilation systems can

be low.

Installation and maintenance costs for the

operation of a mechanical ventilation

system may be very high.

DIFFERENCES NATURAL VENTILATION MECHANICAL VENTILATION

Terms Natural ventilation is a system where

the air is moved through ventilation

openings by natural forces such as

wind pressure and stack effect

Mechanical ventilation system extracts

the air from the ventilation space with

ducts and fans.

Characteristics 1. Natural ventilation for indoor

air quality control

It for achieving acceptable indoor air

quality is essentially based on the

supply of fresh air to a space and

dilution of the indoor pollution

concentration

2. Thermal comfort of the

occupants

Human thermal comfort is defined as

the conditions in which a person would

prefer either warmer or cooler

surroundings

The mechanical ventilation system will

often be controlled by indoor air

quality requirements and in situations

requiring mechanical cooling dictated

by the in door air temperature.

Case study 2

SUPPLYSUPPLY

SUPPLYSUPPLY

EXTRACTEXTRACT

FILTERFILTERBLOWERBLOWER

AHU ROOMAHU ROOM CHILLERCHILLER

CONDENSER WATER PUMPCONDENSER WATER PUMP

CHILL WATER PUMPCHILL WATER PUMP

Ventilation cycle to ‘Galeri Inovasi & Kreativiti’

CHILLER PLANT ROOM

GALERI

Flow of the air ventilation:

1. Water tank supply the water to the chiller .

2. Chiller will compact it into the cold water and supply to the blower

which is located at AHU room.

3. Blower will transform the cold water into the fresh air and supply

to the room.

4. The air distributed by the diffuser equally through the ductwork.

5. Surrounding air will extract by the diffuser from the room to send

back to the AHU room.

6. The filter in the AHU room filtrating the air that extracted from the

room.

7. The air will be re-using together with the fresh air from the blower.

DUCTWORK AND FIRE DAMPER

DIFFUSER

GALLERY

AHU ROOM

INLET FROM CHILLER

FILTER

INSIDE FILTER (COLD WATER FROM CHILLER)

CHILLER PLANT ROOM

CHILLER

CHILL WATER PUMPCONDENSER WATER PUMP

PROBLEM FACING

Unbalanced of air distribution in diffuser into

the room when renovation.

Need maintenance consistently.

CONCLUSION

Ventilation is importance to human for breathing comfortably in doing their daily life activity.

Whether by natural or mechanical ventilation, it is suitable depending on the situation and

location for the ventilation.

Natural ventilation can be a key element of cooling strategies in many climates. In its

simplest version is opening windows and doors, to benefit from breezes. But when in cross

and stack problem, natural ventilation can be part of a more elaborate approach for cooling

homes, involving features like home design, landscape, placement and size of openings and

others. In this situation, mechanical ventilation is the best solution for this situation by

applying one of the methods in mechanical ventilation

Mechanical ventilation is the best application for - high rise building, commercial building

and any enclosed area as it can distribute fresh air

Natural ventilation is the best solution for - saving the energy and good application for

green building but it loses much of its power in cold climates or even in hot-humid climates

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