Building service - analysis

SCHOOL OF ARCHITECTURE, BUILDING & DESIGN BACHELOR OF SCIENCE (HONOURS) (ARCHITECTURE)

BUILDING SERVICE (ARC 2423) PROJECT ONE CASE STUDY ON POINT 92

ANDREA LEE

0314320

CHEN ROU ANN

1001G76463

SWAFAA SHIHAG

0306347

TREVOR HOAREAU 0308914 SOE WOEI HAO

0309924

WILLIAM YAP

0314127

CONTENT 1.0 2.0 3.0 4.0 5.0 6.0 7.0 8.0

Introduction Fire Protection and Safety Electrical Supply Safety Fs Passive Cooling Mechanical Ventilation and Cooling System Conclusion Reference

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1.0 Introduction Under the guidance of a lecturer, we were required to choose a building of at least 4storey high which can be either a public or commercial building (i.e. office blocks, institutional buildings, shopping malls, etc.). With that, we were required to perform a thorough study and analysis of the following services systems associated with the building; i)

Mechanical ventilation and air-conditioning system

ii)

Electrical supply system

iii)

Mechanical transportation system

iv)

Fire protection system and document their findings accordingly.

The purpose of this assignment is to evaluate the understanding on the systems observed and learned in class.

Point 92 was chosen as we felt this iconic office landmark best suited the requirements of the brief. With that, meetings were conducted with the technician of the building, allowing us a detailed tour and understanding inside the inner workings of the place.

Group photo with the technician of Point 92

1.1 Introduction of Point 92

Point 92 Point 92 is an office block that challenges the norm of today’s office buildings. The name itself derives from the area of which it sits on that spans 0.92 acres. This building consists of an 11-storey block, a two-storey arrival hall and a 6.5 storey car park podium. Located on a sloped site overlooking Damansara Perdana and its residential precincts, this building successfully plays with the ambience through the incorporation of day lighting with façade treatments.

The building greatly takes into consideration ‘green strategies’, implemented around the office block resulting in an environmental friendly and sustainable workplace. One of the main features of this building is the unique patterns of its façade. These patterns are derived from the Braille code system, composed of mainly 6 different shapes arranged to spell out the projects name.

In addition, Point 92 showcases local building materials – off form white concrete and local marine plywood, adding to the building’s elegant aesthetics. To overcome the problem of building on a slope, the design opted for in situ concrete wall instead of the

usual precast concrete solutions. Not only was it necessary to use metal formwork in sets to meet with a target schedule, it is also informed of the uniformity issues if the façade was casted in regular sequences. Hence the randomly casted sequence.

‘We had this idea that much of the work place products that are available today had not played creatively on issues the likes of day lighting, ambiance and materiality of the façade. instead, nearly all office developments emphasize efficiency and maximum density as overriding concerns and aims over design and aesthetics, let alone their simple functionality in terms of critical ambiance and spatial plan.’

-

managing director Huat Lim on Point 92’s typology

2.0 FIRE PROTECTION AND SAFETY

2.1 INTRODUCTION AND FUNCTION New buildings and renovation projects need to be designed accordingly to integrate effective, passive and automatic fire protection systems. These are very effective in detecting, containing, and controlling and/or extinguishing a fire.

Natural, manmade, wildfire and incidental fires are taken into account for fire protection.

The analysis done requires more than code compliance or meeting the minimum legal responsibilities for protecting a building; buildings and fire codes are intended avoid the loss of life and limit fire impact on the community. With this, it is necessary to efficiently incorporate code requirements with other fire safety measures as well as design strategies to achieve a balanced and safe design for the people.

2.2 COMPONENTS OF FIRE PROTECTION SYSTEM in POINT 92 (PASSIVE AND ACTIVE) 2.2.2 PASSIVE FIRE PROTECTION Components in a fire protection system may involve both active (electrical equipment) and passive systems. Issues to address in developing a successful fire protection design include: Design Team - it is important that the project delivery team include a Fire Protection Engineer with satisfactory experience and knowledge in fire protection and life safety design. The Fire Protection Engineer should be involved in all phases of design, from planning to occupancy.

Design Standards and Criteria (i.e., Building Code, UBBL etc.) - to be utilized by the design team. This includes legal requirements, voluntary requirements addressing owner's performance needs, and requirements that are sometimes imposed by insurance companies on commercial projects.

Site Requirements - a quality site design will integrate performance requirements associated with fire department access, suppression, and separation distances and site/building security.

Fire department access - Design buildings with uncomplicated layouts that enable firefighters to locate an area quickly. These also provide rapid access to various features such as fire department connections (FDCs), hose valves, wet risers, elevators and stairs, etc.

2.2.2 ACTIVE FIRE EQUIPMENT Basic components found in the alarm system of Point 92 include: i)

fire alarm system

ii)

fire extinguisher

iii)

fire hydrant

iv)

fire sprinklers

v)

hose reels

2.2.2.1 Fire Alarm System A fire alarm system is a set of electric equipment operating together to detect and alert people through visual and audio appliances when smoke/fire is present. These alarms may be triggered from different detectors. The components of the fire alarm system in Point 92 are:- Fire alarm control panel (also known as fire alarm control unit, FACU); This component serves as the nucleus of the system, displaying inputs and system reliabilities, controlling outputs and feed information. [fig.10] -Primary power supply: Commonly the non-switched 120 or 240 Volt Alternating Current source supplied from a commercial power utility. In non-residential applications, a branch circuit is dedicated to the fire alarm system and its elements.

-Initiating devices: These components act as an input to the fire alarm control unit and are both automatic and manual. Break glass triggers [fig.2] are heat detectors or smoke detectors [fig.3]. These detectors come in various kinds (beam, photoelectrical, aspiration, duct). Point 92 uses a laser-beam type scattered-light photoelectric smoke detector. The laser beam allows for the differentiation between dust and smoke particles, resulting in a highly sensitive unit.

-Notification appliances: This component uses energy supplied from the fire alarm system to determine the number of people needed to evacuated an area. This is done by means of a flashing lights, strobe lights, electromechanical horns, "beeper horns", chimes, fire bells [fig. 1], speakers, or a combination of these devices.

Fig.1

Fig.2

Fig.3

UBBL 225. (1) Every building shall be provided with means of detecting and extinguishing fire and with fire alarms together with illuminated exit signs in accordance with the requirements as specified in the Tenth schedule to these By-laws.

2.2.1.2 Fire Sprinkler System A fire sprinkler system is an active fire protection method that provides sufficient pressure and flow rate to a water distribution piping system, onto which fire sprinklers are connected.

Each closed-head sprinkler is held closed by a heat-sensitive glass bulb which applies pressure to a pipe cap, preventing water from flowing until the ambient temperature around the sprinkler reaches the design activation temperature of the individual sprinkler head. In this standard wet-pipe sprinkler system at Point 92, each sprinkler activates independently when the predetermined heat level is reached. Thus, only sprinklers close to the fire will operate. This maximizes water pressure over the point of fire origin, minimizing water damage to the building.

Water from main supply

Standby pump

Duty pump

Jockey pump

Supply to all floors Flow switch/ butterfly valve

Sprinkler heads

Maximum Ceiling Temperature

Temperature

Temperature

Classification

100°F / 38°C

Rating 135-170°F / 57-77°C

Ordinary

Color Code

Liquid Alcohol

(with Fusible

in Glass Bulb

Link)

Color

Uncolored or

Red (155°F /

Black

68°C)

sprinkler head in point 92 (standard type)

Fig.5 : Sprinkler diagram

sprinkler duty pump

duty pump control panel

jockey pump

[fig.9] fire alarm monitoring system.

fire alarm control panel

UBBL: 238: Every large premises or a building exceeding 30.5m in height shall be provided with a command and control center located on the designated floor and shall contain a panel to monitor the public address, fire brigade communication, sprinkler, water flow detectors, fire detection and alarm systems and with a direct telephone connection to the appropriate fire station by-passing the switchboard.

2.2.1.3 Fire hydrant and Wet riser Each fire hydrant is connected to a large underground pipe that carries water. A fivesided wrench is required to open up one or more of the covers, connecting hoses to the openings in order to get water out. The same wrench is used to turn the 'stem nut', similar to a regular faucet's cold or hot water knob. Water comes up through the pipe, through the openings, and into the hoses that lead to the fire engines.

The water that comes out of the hydrant is the same water that comes into homes, businesses, and schools. This water has a water pressure of about 50-80 psi (pounds per square inch). This pressure is high enough for everyday use, but is not high enough for use by firefighters. So, the pumps on the fire engines increase the pressure. Then, there are smaller hoses that attach to the engines that firefighters use to fight fires.

Fire hydrant located at the entrance of the premises

Wet riser found in Point 92

Wet rising mains are installed in high rise buildings due to the extra pressures needed to pump water to high levels. A Wet riser is a supply system intended to supply water to multiple levels of a building, as a component of its firefighting systems. They are beneficial to the fire service in two respects. Firstly they provide a fixed distribution

system within the building that requires no fire service resources or equipment.

Secondly it is designed as part of, and to maintain, the compartmentation of the building.

wet riser diagram (source: http://www.highrisefirefighting.co.uk/wr.html)

part of floor plan showing location of Wet Riser (WR) Smoke detector (SD) and hose reel (HR) in relation to the Bomba Lift (BL)

UBBL: 231. (1) Wet rising systems shall be provided in every building in which the topmost floor is more than 30.5 meters above fire appliance access level.

(2) Every building shall be served by at least one fire hydrant located not more than 91.5m from the nearest point of fire brigade access.

(4) Each wet riser outlet shall comprise standard 63.5mm instantaneous coupling fitted with a hose of not less than 38.1mm diameter equipped with an approved typed cradle and a variable nozzle.

(5) A wet riser shall be provided in every staircase which extends from the ground floor level to the roof and shall be equipped with a three-way 63.5mm outlet above the roof line.

UBBL 248. (1) Wet riser, dry riser, sprinkler and other fire installation pipes and fittings shall be painted red.

2.2.1.4 Hose reel Fire hose reel systems consist of pumps, pipes, water supply and hose reels located strategically in a building, ensuring proper coverage of water to combat a fire. A normal water supply is used for the hose reel which is from the dedicated hose reel tank (fig.).

The dedicated hose pump ensures adequate water pressure is delivered to each hose reel.

The process is shown below:

TANK

PUMP

DELIVERY

part of roof plan showing dedicated tank and pump

hose reel in Point 92

Point 92 has installed Bomba Malaya certified hose reels at strategic positions on all floors of the building.[fig.17]

hose reel

hose reel

[hose reel location on level 11.]

The system is manually operated and activated by the aid of valves, enabling water to flow into the hose. The system pressure loss will activate the pump ensuring adequate water flow and pressure to provide a water jet of a minimum of 10 meter from the nozzle.

2.2.1.5 Fire extinguishers Point 92 uses Carbon dioxide fire extinguishers. These are ideal for electrical fires or flammable liquid fires. As CO2 is harmless to electrical equipment, it is suitable to be used in offices and workshops. Both dry powder and carbon dioxide extinguishers have non-conductive, anti-static horns.

CO2 fire extinguisher

fire extinguisher diagram(source:www.firesafe.org.uk)

UBBL: 227. Portable extinguisher shall be provided in accordance with the relevant codes of practice and shall be sited in prominent positions on exit routes to be visible from all directions and similar extinguishers in a building shall be of the same method of operation.

Analysis It is clear from our observations that Point 92 has adhered to the majority of by-laws required for fire protection safety. Due to the coverage of this report, only specific bylaws have been mentioned, however, they are not the only by-laws respected.

3.0 Electrical Supply System

3.1 Introduction The electrical supply system is a complex procedure of the distribution of electricity.

Every step of this process has an electrical and mechanical service device that supports it. Point 92’s electrical supply system was studied thoroughly, covering how electricity is used, distributed as well as the electrical backup system of it all. Types of lightings and the allocation plan of the direct lightings were also analyzed.

3.2 Case Study 3.2.1 Transformers

transformer A transformer changes the alternating current (ac) of one voltage to an alternating current of another voltage. Although transformers are generally known as electrical components, the transformer used in building works differ. They consist of iron cores which are wounded into two (or more) coils. Voltage impressed on the primary winding induces a voltage in the secondary winding according to the proportion of the ratio of turns in the two coils. A step down transformer has a larger number of turns in its primary winding than in its secondary one.

Transformers are mainly used to step down an incoming 4160 V service to 480 V for distribution within a building. There are different types of building work transformers, these are available in a single or three-phase construction. The transformer power capacity is rated in kilovolt-amperes (kVA). These are generally specified by the type, phase, voltages, kVA rating, sound power level and insulation class. Thus, 112.5kVA, three phase, 480/120 to 208-V , air cooled, indoor, dry type transformer with 220 Celsius insulation system and 115 Celsius rise, 45 Decibel maximum sound level, represents an optimal transformer description.

TNB 3.2.2 TNB (Tenaga National Berhad) The leading power supply of Malaysia is the TNB. Other power suppliers in Malaysia include SESCO, SESB, IPP, and Co – Generator.

The Tenaga National Berhad (TNB) is a listed public company. This company is responsible for generating, transmitting, and distributing energy throughout the whole peninsular of Malaysia. The transmission voltage networks are 500kV, 275kV and 132kV, thus the distribution voltages are 33kV, 11kV and 415/240 Volts.

TNB substation acg.com.my

3.2.3 Malaysia Peninsula Grid System Fig 1 National power Grid http://www.geni.org/

The ‘Malaysia Peninsula Grid System’ is the primary electricity transmission network linking the electricity generation, transmission, distribution and consumption in Malaysia.

It is operated and owned solely by TNB (tenaga national berhad) with approximately 420 substations in the Peninsular Malaysia. These are linked together by the extensive network of transmission lines operating at 132kV, 275kV and 500kV. The power generated is not only from TNB, but from IPP are both carried by the national grid towards customers connected to the various distribution networks. They are electrically

interconnected to the transmission network of the electricity generating authority of Thailand (EGAT) and also to Singapore Power.

Among the advantages of the national grid system is that it provides multiple paths between various generation sources and loads. In addition, it allows power transfers from one geographic area to another, achieving overall system operating economics.

3.2.7 Power Distribution Point 92 obtains its electrical supply through the MSC system. Multimedia Super Corridor (MSC) - a world-first, world-class act - which is a length of greenfield "corridor", 15 kilometers wide and 50 kilometers long (9 by 30 miles - roughly the size of Singapore) located 30km (20mi) south of the capital.

This corridor stretches from the Kuala Lumpur City Center (KLCC) down south to the future federal administrative city of Putrajaya and Kuala Lumpur International Airport (KLIA).

Point 92 system receives from 2 feeders from TNB into 2 sets of VCB (vacuum circuit breaker). From the VCB, the electrical supply then transfers to two stations - one from the Landlord and one for the tenant. From the stations, the electrical supply is directed to a transformer which supplies to the MSB (main switch board) that in present in the control rooms.

Point 92 has 4 MSB located throughout the floors and out of the 4 MSB, one of it is the EMSB (essential Switch Board) this Switch board supplies power to essential equipment such as lifts, firefighting pumps and emergency lights. However, during a black out or a power failure, the EMSB will continue its supply of power to the equipment due to the fact that it is connected to a Genset ( Diesel powered Generator).

Point 92 dedicates one MSB to supply to its building services such as the chiller, AHU as well as lift in the control room as a way to centralize its controls for all the building services. The following MSB are then connected to SSB (Sub Switch Board) which then connects to a DB (Distribution Board) which can be found in every floor.

UBBL 253 (1) Emergency power system shall be provided to supply illumination and power automatically in the event of failure of the normal supply or in the event of an accident to elements of the system supplying power and illumination essential for safety to life and property

3.2.4 Switchgear and Switchboard Switchgears are known as ‘unit substations’. Its function is to accept incoming high voltage power supplies, transforming them into a voltage that can be utilized in the facility. Later, it distributes the low voltage power through an associated low voltage switchgear. Modern switchboards are all dead front, this means that they all have circuit breakers, switches, fuses and live parts completely enclosed in a metal structure.

3.2.5 VCB (Vacuum Circuit Breaker).

A vacuum circuit breaker is where arc quenching takes place in a vacuum. It is suitable for medium voltage application. The process of opening and closing current carrying contacts is done in a vacuum interrupter. The vacuum interrupter contains a steel arc chamber in the center of the VCB and symmetrically arranged with ceramic insulators. Pressure inside the interrupter is normally maintained at 10 to 6 bar. The material used for current carrying contacts is important as it effects the performance of the VCB. CuCr is the most ideal material to make VCB contacts.

3.2.6 Generator ( Genset ) The Engine Generator Sets’ generate power in emergency cases. Whenever there is a blackout of or any energy crisis, the generator will have enough energy to provide for important spaces in the building. Only directly connected lights will be provided by the generator whenever a blackout occurs.

Engine Generator Sets comprises of three components which are the fuel systems, the set itself, plus exhaust facilities and the space housing the equipment. One of the

advantages of the generator sets are the unlimited kVA capacity. Duration of power are only limited by the size of the fuel tank, use for peak load shaving and with well maintenance, indefinite life.

Although the disadvantages of the Engine Generator Sets are the noise it creates while running, the vibration, the nuisance of exhaust piping and exhaust the need for constant maintenance and regular testing , and difficulties with fuel storage. The gasoline can only be stored for a year at most, and disposal is difficult. Point 92 uses a Genset which can be referred to as a diesel power generator.

UBBL 253 (5) current supply shall be such that in the event of failure of the normal supply to or within the building or group of buildings concerned, the emergency lighting or emergency power, or both emergency lighting and power will be available within 10 seconds of the interruption of the normal supply. The supply system for emergency purposes shall comprise one or more of the following approved types: B) Generator set: A generator set driven by some form of prime mover and of sufficient capacity and proper rating to apply circuit carrying emergency lighting or lighting and power with suitable means for automatically starting the prime mover on failure of the normal service

3.2.8 Distribution box

The distribution box is situated in every floor of the building, as every distribution box gives out electricity to every floor respectively. This box serves as the central distribution points for all the circuits that run to lights, receptacles and appliances throughout the building. The Distribution box is usually installed mounted on a wall commonly in the store. It is directly connected to the main switchboard of the building, also helping in the control and protection of all the circuits of the electrical system.

Analysis Point 92 building encompasses the essential electrical services following the UBBL law and requirement. Figure explains the analysis of the lighting electrical system of the point 92 building in summery.

EMERGENCY LIGHTS

KELUAR SIGN

UBBL 253 (1) Emergency power system shall be provided to supply illumination and power automatically in the event of failure of the normal supply or in the event of an accident to elements of the system supplying power and illumination essential for safety to life and property

5.0 Passive Cooling Systems

Passive cooling systems are building design approaches that focus on heat dissipation as well as heat gain control in a building in order to improve its thermal comfort with little energy consumption. In short, these systems are air conditioning without the need of energy, taking advantage of the sun’s energy to maximize heating or cooling based on a building’s sun exposure.

Point 92 has received many positive comments and was featured on the cover of d+a, one of the established design magazines in the region. The building is also a certified green building by the Green Building Index (GBI) of Malaysia.

Proof of Point 92’s certification by the Green Building Index

5.1 Ventilation Ventilation as a natural cooling strategy that uses the physical properties of air to remove heat or provide cooling to occupants. In select cases, ventilation can be used to cool the building structure, which subsequently may serve as a heat sink.

Cross ventilation Cross ventilation techniques use high and low pressure zones created by wind to draw fresh air through a building. The strategy of cross ventilation relies on wind to pass through the building for the purpose of cooling the occupants.

Cross Ventilation Diagram

Section showing cross ventilation path in Point 92’s reception area Cross ventilation requires openings on two sides of the space, called the inlet and outlet. The sizing and placement of the ventilation inlets and outlets determine the direction and velocity of cross ventilation through the building. Generally, an equal (or greater) area of outlet openings must also be provided to provide adequate cross ventilation.

Because of Point 92’s flat, horizontal plan, the effectiveness of cross-ventilation across the plan is increased. As the building is supported by columns, the ground level has high ceilings, allowing natural ventilation and daylighting. It also opens up to unobstructed views of the landscape from the ground level.

5.2 Heat Gain Control

Controlling the heat a building gains from its environment is what passive cooling is all about. Keeping unwanted heat out in hot climates is crucial. A key green feature of Point 92 the insitu placed white concrete façade, which comprises of 150mm thick walls with only 38% openings for windows.

Exterior view of the building This façade has a high thermal mass which conducts a significant proportion of incoming thermal energy deep into the material. This means that instead of the first couple of millimetres of a wall heating up 5–10 degrees, the entire wall heats up only 1– 2 degrees. The material then re-radiates heat at a lower temperature, but re-radiates it for a longer period of time.

With this, the occupants in the building stay more comfortable, for a longer period of time. When the internal temperate of the building falls at night, energy stored within the walls is radiated out.

5.3 Vegetation

Rest area in Point 92 Part of the building is surrounded by a dense amount of vegetation (refer to pictures above). These vegetation serve as a protective barrier which shields the building from solar radiation and heat penetration. With this, the demand for mechanical cooling systems are reduced.

As an office plan, the generating feature of the floor plate is in fact a cut-out space which comprises of several levels of voids connected through gardens and meshes of vertical planting. The centre support column is braced to either side with different thickness of beams each corresponding to different floor forces framing the vertical space that is the garden. The terrace is specially lit and designed grandly to give the

viewers from outside a taste of the garden, at the same time allowing a great amount of wind to enter the area, ensuring thermal comfort.

6.0 Mechanical Ventilation and Cooling System 6.1 Introduction The air conditioner (often referred to as A/C, AC or aircon) is a device that has grew to become a necessity in majority of the buildings in countries experiencing hot climate.

This device serves in altering the properties of air to more comfortable conditions, ensuring the thermal comfort of users and ultimately improving the indoor air quality of a space. Air conditioners remove heat from a certain location to give a chilled air effect.

The main process is that the air circulation is drawn to the condenser containing refrigerant gas. The circulation process undergoes three stages where in the evaporator carries secondary cooled refrigerant passing through to release ice-cold air into the area. Therefore, an air conditioning system can make the air indoors cold and release hot air outside. This is the main function of the refrigerant. The air conditioning system is composed of mechanical components which are the following: blower, chemical refrigerant, condenser, compressor and evaporator coil.

BY LAW (1) Where permanent mechanical ventilation or air conditioning is intended, the relevant building by-laws relating to natural ventilation, natural lighting and heights of rooms may be waived at the discretion of the local authority.

(2) Any application for the waiver of the relevant by-laws shall only be considered if in addition to the permanent air-conditioning system there is provided alternative approved means of ventilating the air-conditioned enclosure, such that within half an hour of the air-conditioning system failing, not less than the stipulated volumn of fresh air specified hereinafter shall be introduced into enclosure during the period where the air-conditioning system is not functioning.

(3) The provisions of the Third Schedule to these By-laws shall apply to buildings which are mechanically ventilated or air-conditioned.

(4) Where permanent mechanical ventilation in respect of lavatories, water closets, bathrooms or corridors is provided for and maintained in accordance with the requirements of the third schedule to these By-laws, the provsions of these ByLaws relating to natural ventilation and natural lighting shall not apply to such lavatories, water-closets, bathrooms or corridors.

6.2 Case study 6.2.1 Cooling System and Mechanical Ventilation The purpose for ventilation is to provide fresh air for comfort and to ensure health indoor air quality by diluting contaminants. Historically, people have ventilated buildings to provide source control for both combustion products and objectionable odours.

Currently, a wide range of ventilation technologies is available to provide ventilation in dwellings including both mechanical systems and sustainable technologies.

The type of mechanical ventilation used in Point 92 was chosen in respect to the Malaysian climate. In warm and humid climates, infiltration was minimized and prevented to reduce interstitial condensation (which occurs when warm, moist air from inside a building penetrates a wall, roof or floor and meets a cold surface). In these cases, a positive pressure mechanical ventilation system is often used. Conversely, in cold climates, exfiltration needs to be prevented to reduce interstitial condensation, and negative pressure ventilation is used.

In a positive pressure system, the room is in positive pressure and the room air is leaked out through envelope leakages or other openings. In a negative pressure system, the room is in negative pressure, and the room air is compensated by “sucking” air from outside. A balanced mechanical ventilation system refers to the system where air supplies and exhausts have been tested and adjusted to meet design specifications.

The room pressure may be maintained at either slightly positive or negative pressure, which is achieved by using slightly unequal supply or exhaust ventilation rates.

If well designed, installed and maintained, there are a number of advantages to a mechanical system. 

Mechanical ventilation systems are considered to be reliable in delivering the designed flow rate, regardless of the impacts of variable wind and ambient temperature. As mechanical ventilation can be integrated easily into airconditioning, the indoor air temperature and humidity can also be controlled.



Filtration systems can be installed in mechanical ventilation so that harmful microorganisms, particulates, gases, odours and vapours can be removed.



The airflow path in mechanical ventilation systems can be controlled, for instance allowing the air to flow from areas where there is a source (e.g. patient with an airborne infection), towards the areas free of susceptible individuals.



Mechanical ventilation can work everywhere when electricity is available.

6.2.2 Mechanical Ventilation in Point 92 Point 92 has a total of 3 refrigerants, 3 chillers and 4 big pumps for water, 1 being present for emergency use.

Cooling System Layout in Point 92

From the diagram above, mechanical ventilation in Point 92 can be further broken down into 3 cycles: 1. Cooling tower to chill down refrigerant (medium: air) 2. Air Handling Unit (AHU) to cool down air (medium: water) 3. Fan Coil Unit (FCU)

6.2.2.1 Cooling Towers Cooling towers are an integral component of many refrigeration systems, they serve to provide comfort and process cooling across a board range of applications. Besides office buildings, they are also commonly used to provide comfort for large commercial buildings including airports, conference centres, hospitals and hotels.

These cooling tower structures have a tendency to vary greatly in size and design, but they all function to provide the same thing; liberation of waste heat extracted from a process or building system through evaporation of water.

Cooling tower, Point 92.

Cooling water return & cooling water supply pipe.

Cooling towers can be divided into two distinct categories: open circuit (direct contact) and closed circuit (indirect) systems. Point 92 uses an open circuit system.

In open circuit systems, the recirculating water returns to the tower after gathering heat from the building. This heat is distributed across the tower where the water is in direct contact with the atmosphere as it recirculates across the tower structure.

Return fluid (often water. Or sometimes water mixed with glycol) exposed directly to the air.

Closed circuit systems differ in that the return fluid circulates through the tower structure in a coil, while cooling tower water recirculates only in the tower structure itself. In this case, the return fluid is not exposed directly to the air.

Heat in the cooling water is removed by letting air come into contact with it. Water is spread out and allowed to drop by from a height (refer to picture above). Plastic fillings are also arranged so it increases the wetted surface of water while it is dropping, providing better contact between air passages and water.

There are 2 types of designs for cooling towers: Cross Flow Counter Flow Point 92 uses the cross flow design.

Cross Flow

As the name suggests, the flow of water is at right angles to the flow of air. The cooling tower for this type of design is usually shaped like a box. Warm water is pumped to the top of the cooling tower where it I distributed to the sides and allowed to drop. Plastic air intake lovers at the sides of the cooling tower allow the water to spread out while dropping. Air from the outside is sucked into the cooling tower by several fans located at the top of the box-like structure.

When incoming air comes into contact with the dropping water, the latter is cooled.

Cooled water is then collected at the bottom of the tower. This water is then pumped pit again and circulated through the chiller. The heat from the chiller is transferred to it again. The warm water then returns back to the top of the cooling tower and the cycle repeats.

6.2.2.2 Air Handling Units (AHU)

Air handling units are used to supply and circulate air around the building. AHU systems are intended for the central preparation of air, allowing all basic functions. This includes heating, cooling filtration, humidification, dehumidification, head recovery and regeneration.

AHU is connected to the air distribution ductwork. These ventilation systems work in a way that air is drawn back from an interior space. The air passes through cooling coils, mixing it with fresh air. After that, it is channelled back to its interior space. In most cases, few AHUs are connected to one chiller.

1. Filters 2. Cooling coil 3. Fan

AHU System in Point 92

AHU unit in Point 92 The AHU contains a set of supply and exhaust fans which take air in and out of spaces or zones within the building. The air pump creates pressure difference, causing airflow.

Some zones do not have human occupancy. This results in different ventilation and temperature constraints. With sensors, the AHU works to maintain the temperature and air circulation.

Cross section of fan section After air is pumped though the AHU, it goes through a series of filters to ensure it is well purified. Here, air is filtered and foreign substances are removed from the air.

AHUs have cooling coils consisting of a series of pipes oscillating back and forth. These pipes have metal fins attached to them, where chilled water from the cooling tower passes through. As the air passes over the pipes and the fins, it gets cooled down.

Cooling Coil

Lastly, the warm air is pumped back into the AHU system and cycle repeats. Outside air is sucked in to be missed with the return air, this provides the correct proportion of air to be distributed to the space, preventing air from becoming stale.

Opening to bring in fresh air

6.2.2.4 Fan Coil Unit A fan coil unit is a device consisting of cooling coil and fan. It is used for cooling and is usually piped with chilled water. It is a smaller version of AHU and is ceiling mounted, this unit is situated in the lift lobbies in Point 92.

FCU consists of a cooling coil and a fan section. The fan cycles the air continuously and pass through the cooling coil that is supplied with cold water.

Fan coil unit system in Point 92

Analysis It is optional to choose this system due to its efficiency and the ability to save energy.

AHU unit in each floor

7.0 Conclusion

Through the analysis and studies conducted on Point 92, we can conclude that this sustainable building is not only distinctive and cost effective, but also a building that showcases good building services for the people. Building services have been called "the systems that brings a building to life" systems involved contribute greatly to the overall life inside a building, ensuring personal comfort and safety of all human activities.

We would like to end this report with appreciation to the department of technicians of Point 92, as well as our tutor Mr Siva who guided us throughout the tutorials conducted.

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