BUILDING SERVICES
Writers Nurul Izza Bt Abdul Ghani Manisah Bt Mohamad Nur Hanani Bt Daud Aidalia Bt Endut Jusma Bt Jaafar
CIVIL ENGINEERING
Acknowledgement Special Thanks To The Writers
Nurul Izza Bt Abdul Ghani Manisah Bt Mohamad Nur Hanani Bt Daud Aidalia Bt Endut Jusma Bt Jaafar
Publications & Declaration
All rights reserved. No part of this publication may be reproduced or transmitted in any form or by any means, electronic or mechanical including photocopy, recording or any information storage and retrieval system, without permission in writing form from JPPKK.
Also Thanks To
E Learning POLISAS for countless effort in completing this eBook project.
Abstract
Building Services| | Volume I
BUILDING SERVICES focuses on the basic concepts and the principles of the systems in a building. The course emphasizes on the electrical installation system, fire prevention system, building transportation system, air conditioning system, maintenance works and the demolition works.
Chapters
Building Services| | Volume I
01
ELECTRICAL SYSTEM
This topic covers the electrical system in building included the phases of electric supplies, types of electrical wiring, fitment in electrical wiring and symbols in electrical system.
03
TRANSPORTATION IN HIGH RISE BUILDING
This topic covers the scope of building transportation system such as an escalator, elevator, lift and its safety procedures.
02
FIRE PROTECTION SYSTEMS
It consists of cause and source of fire, how it spread, the fire prevention system and class of fire.
04
AIR CONDITIONING SYSTEM
This topic covers the basic and working principles of air conditioning system.
05
MAINTENANCE WORKS
This topic covers the scope of maintenance works, the Building Maintenance Category refer to BS3811 and its maintenance schedule.
CHAPTER 1
ELECTRICAL SYSTEM
CHAPTER 1 ELECTRICAL SYSTEM IN BUILDING Course Learning Outcome At the end of this topic students will be able to: Choose appropriate building services system with consideration of safety procedures, rules and regulation by the authority Identify building services system with consideration of the environmental impact
THE SINGLE PHASE OF ELECTRICAL SUPPLY Single-phase electric power refers to the distribution of alternating current electric power using a system in which all the voltage of the supply very uniformly. only two wires (neutral or red / blue/yellow) A single-phase load may be powered from a three-phase distribution system either by connection between a phase and neutral ( 120V or 220V), or by connecting the load between two phase (120V and 120V, the total being 240V or 220V and 220V, the total being 440V).
Single Phase DB board
Single-phase power distribution is widely used especially in rural areas, where the cost of d three-phase distribution network is high and motor loads are small and uncommon. Usually for residential Single Phase supply system normally installed in small premises such as homes, small shops and so on, where the load on the premise that there is a small number. The overall total current load not exceeding 60 Amp. Single-phase distribution is used when loads are mostly lighting and heating, with few large electric motors.
THREE PHASE OF ELECTRICAL SUPPLY Three-phase electric power is the most common method use by electric power distribution grids worldwide to distribute power. Large consumer such as large building, shopping centers, factories, office blocks, and multiple-unit apartment blocks usually need three-phase service. For three phase supply systems are normally installed in medium to large premises where current load more than 60 Amp. It is also installed on large premises such as factories, buildings and so on. The loading in some large building may be to high for the local low or medium voltage system to provide and a private substation must therefore be installed, supplied from the high voltage cables from the TNB station. Sub-station are often required for factories and hospitals. Have wires :neutral (1) and red/ blue /yellow (3) 415V nominal voltage Three phase system may or may not have a neutral wire. A neutral wire allows the three phase system to use higher voltage while still supporting lower voltage single phase appliances. In high voltage distribution situation, it is common not to Three Phase DB Box
have neutral wire.
DIFFERENCE BETWEEN SINGLE PHASE AND THREE PHASE
ADVANTAGES & DISADVANTAGES OF SINGLE PHASE Advantages Almost all residential supplies are single phase supplies as the domestic appliances require a small amount of power to run lights, fans, coolers, heaters, small air conditioners etc. The design and operation of a single phase power supply system is often simple. Depending on the region, a single phase supply is sufficient for loads up to 2500 Watts. Disadvantages Small single phase motors (usually less than 1kW) cannot start directly with the help of a single phase supply as there isn’t sufficient initial torque for the motor. So, additional circuitry like a Motor Starters (like a starter capacitor in fans and pumps) are needed for proper operation. Heavy loads like industrial motors and other equipment cannot be run on a single phase supply
Single Phase Diagram
ADVANTAGES & DISADVANTAGES THREE PHASE Advantages For the same power, a three phase power supply uses les wire than a single phase power supply. Three phase power supply is usually the preferred network for commercial and industrial loads. Although in some countries (like most European Countries, for example), even the residential supply is a three phase supply. can run larger loads very easily. Large three phase motors (usually used in industries) do not require a starter as the phase difference in the three phase power supply will be sufficient to provide enough initial torque for the motor to start. Almost all the power generated in a three phase power. Although there is a concept of multi-phase power, studies found that a three phase power supply is more economical and easy to produce. The overall efficiency of the three phase power supply is higher when compared to that of a single phase power supply for the same load. Disadvantages 2 overhead wires are required. So cost increases. System voltage 3.3 KV is less as compound to 25KV so because of low voltage, current is high. So, I2R losses are more and less transmission efficiency. More current, more I.R (voltage) drop. So distance between 2 substations is less. So we require more no. of substation.
TYPES OF WIRING
Surface Wiring
FITMENT IN THE ELECTRICAL WIRING Conductors A conductor is an electrical component that conducts and confines the flow of electrical current within itself. Conductors are made of high conductivity (low resistivity) material to minimize the loss of power and drop in voltage. Made in cylindrical form as wires, but they also made in square or rectangular section. Material: copper, aluminum, etc.
Insulator A true insulator is a material that does not respond to an electrical field and completely resists the flow of electric charge. In practice, however, perfect insulators do not exist. Insulators are used in electrical equipment support and separate electrical conductors without allowing current through themselves. Insulators are commonly used as a flexible coating on electric wire and cable. These materials are used in electrical equipment as insulators or insulation. Their function is to support or separate electrical conductors without allowing current through themselves. Electrical wires may be insulated with rubber, plastics, ceramics and glass.
Electricity A protective device for electrical equipment that reduces excessive voltage resulting from lightning and to prevent user contact from dangerous voltage electrical if insulation fails, to a safe level by grounding the discharge. Type of electricity protection wiring – lightning, earthing/ grounding and fuses.
Lightning Lighting causes building fires, burn out electrical appliances, disrupts telephone service and radio communication. Lightning protection system includes lightning rods, metal conductor and ground electrodes to offer a low resistance path to ground and to take any high voltage currents from lightning strike away from the building.
Building Lightning Protection System
ELECTRICITY
Fitment in Electrical Wiring
Earthing
Provide an alternative path for the fault current to flow so that it will not endanger the user. Ensure that all exposed conductive parts do not reach a dangerous potential. Maintain the voltage at any part of an electrical system at a known value so as to prevent over current or excessive voltage on the appliances or equipment.
TECHNOLOGIES USED IN ELECTRICAL INSTALLATION SYSTEM Robotics The smart grid Wearables Prefabricated products Energy-efficient lighting technologies The Revolution of Betavoltaics Na-TECC Smartwatch Client relationship and project management software The internet of things (IoT) Drones Smart Helmet and AR Prefabrication BIM Electrical Subcontractor Scheduling Software
New Technologies
SAFETY PROCEDURES BASED ON MS IEC STANDARD The Department of Standards Malaysia (STANDARDS MALAYSIA) is the national standards and accreditation body of Malaysia. The main function of STANDARDS MALAYSIA is to foster and promote standards, standardisation and accreditation as a means of advancing the national economy, promoting industrial efficiency and development, benefiting the health and safety of the public, protecting the consumers, facilitating domestic and international trade and furthering international cooperation in relation to standards and standardisation. Malaysian Standards (MS) are developed through consensus by committees which comprise balanced representation of producers, users, consumers and others with relevant interests, as may be appropriate to the subject at hand. To the greatest extent possible, Malaysian Standards are aligned to or are adoption of international standards. Approval of a standard ,as a Malaysian Standard is governed by the Standards of Malaysia Act 1996 [Act 549]. Malaysian Standards are reviewed periodically. The use of Malaysian Standards is voluntary except in so far as they are made mandatory by regulatory authorities by means of regulations, local by-laws or any other similar ways.
SAFETY PROCEDURES BASED ON MS IEC STANDARD
Malaysian Standard in Electrical Installation Building Book
GREEN TECHNOLOGY BY SOLAR AND WIND IN THE ELECTRICAL INSTALLATION SYSTEM 1. Solar Power This common renewable, green energy source is usually produced using photovoltaic cells that capture sunlight and turn it into electricity. Solar power is also used to heat buildings and for hot water as well as for cooking and lighting. Solar power has now become affordable enough to be used for domestic purposes including garden lighting, although it is also used on a larger scale to power entire neighbourhood. 2. Wind Power Particularly suited to offshore and higher altitude sites, wind energy uses the power of the flow of air around the world to push turbines that then generate electricity. 3. Hydropower Also known as hydroelectric power, the flow of water in rivers, streams, energy. Hydropower can even work of water through pipes in the home rainfall or the tides in the oceans.
this type of green energy uses dams or elsewhere to produce on a small scale using the flow or can come from evaporation,
4. Biomass This renewable resource also needs to be carefully managed in order to be truly labelled as a ‘green energy’ source. Biomass power plants use wood waste, sawdust and combustible organic agricultural waste to create energy. While the burning of these materials releases greenhouse gas these emissions are still far lower than those from petroleum-based fuels.
GREEN TECHNOLOGY BY SOLAR AND WIND IN THE ELECTRICAL INSTALLATION SYSTEM 5. Geothermal Energy This type of green power uses thermal energy that has been stored just under the earth’s crust. While this resource requires drilling to access, thereby calling the environmental impact into question, it is a huge resource once tapped into. Geothermal energy has been used for bathing in hot springs for thousands of years and this same resource can be used for steam to turn turbines and generate electricity. The energy stored under the United States alone is enough to produce 10 times as much electricity as coal currently can. While some nations, such as Iceland, have easy-to-access geothermal resources, it is a resource that is reliant on location for ease of use, and to be fully ‘green’ the drilling procedures need to be closely monitored.
Solar Power Collection Area
CHAPTER 2
FIRE PROTECTION SYSTEM
CHAPTER 2 FIRE PROTECTION SYSTEM Course Learning Outcome At the end of this topic students will be able to: Choose appropriate building services system with consideration of safety procedures, regulation by the authority
rules
and
Identify building services system with consideration of the environmental impact
INTRODUCTION Fire safety refers to precautions that are taken to prevent or reduce the likelihood of a fire that may result in death, injury, or property damage, or to reduce the damage caused by a fire. Fire safety measures include those that are planned during the construction of a building or implemented in structures that are already standing, and those that are taught to occupants of the building. Threats to fire safety are referred to as fire hazards. A fire hazards may include a situation that increases the likelihood a fire may start or could prevent the escape if the fire occurs.
FIRE CAN BE DEFINES AS: A chemical reaction that occurs when combustible material and oxygen touches source of heat or ignition
SOURCE OF FIRE Oxygen Fire requires oxygen to causes it begins, occurs or continues. The main source of oxygen is air. Heat commonly knows as a source of ignition. It is energy that can be imposed on a mixture of oxygen and fuel to start fires. Fuel include organic fuel such as petrol, paper and wood.
CAUSE OF FIRE Use a lot of inflammable materials for wall, ceiling, roof. Careless use of electrical equipment and using equipment that is damaged. Wiring system is not good. If found to be unsafe, rewiring to be done. .Removal of the still burning cigarette butts. Negligence of the user on the use of combustible fuel, mosquito repellent, gas stove.
Fire
FIRE IS SPREAD BY THREE METHOD
CONDUCTION Some metal
materials, such as and absorb heat
readily and transmit it to other rooms by conduction, where it can set fire to combustible items that are in contact with the heated material. RADIATION Radiation transfers heat in the air in the same way that an electric bar heater heats a room. Any material close to a fire will absorb the heat until the item starts to smoulder and then burn. Radiation transfers heat in the air in the same way that an electric bar heater heats a room. Any material close to a fire will absorb the heat until the item starts the smoulder and then burn.
Methods of fire spread
CONVECTION Fire and smoke spread by convection is the most dangerous and causes the major proportion of injuries an deaths. When fire starts in an enclosed space, the smoke rising from the fires becomes trapped by the ceiling and then spreads in all directions to form an ever-deepening layer over the entire room space. The smoke will pass through any holes or gaps in the walls, ceiling and floor into other parts of the building. The heat from the fires gets trapped in the building and the temperature rises.
FIRE PREVENTION SYSTEM IN THE BULDING Purpose : To provide adequate protection from fire hazard to building occupants and reduce damage to property. Categorized to two systems: Passive Fire Prevention Active Fire Protection
Fire Alarm System
PASSIVE FIRE PROTECTION (PSP) Protection system available on the building structure, function to stop spread of fire and smoke so that residents can seek refuge using it as a route out to a safe place as a place to locate firefighters and fire fighting equipment. PFP try to prevent fires or slow down the spread through the use of fire resistant walls, floors and doors.
Fire Safety Door
Example of PFP Fire rated walls, floors, ceiling and roofs. Fire and smoke control doors Fire and smoke stopping seals, collars, pillow, blankets, etc for services penetrations. Fire rated protective coatings for structural steel members etc Fire and smoke dampers/ curtains Fire rated glass systems Fire rated lift landing doors Fire rated ducting
ACTIVE FIRE PROTECTION ( AFP) A fire protection system installed permanently in the building to control and fire fighting; either manual or automatic. To provide protection to building occupant with fire detection method, control and fire fighting. To detect, control, and fire-fighting at early stage for prevent damages and destruction resulting from fire.
Fire protection
Examples of AFP : Fire Hydrant System Dry And Wet Riser System Sprinkler System Fire Alarm System (manual/automatic) Fire Extinguisher Water Spray System Fire Detection
CLASS OF FIRE Fires are classified into four groups according to sources of fuel: Class A, B, C, D based on the type of fuel source. Table below describes the classifications of fire which can be used in making hazard assessment.
TYPES OF FIRE AND CAUSES
FIRE PREVENTION PROCEDURE In case of fire : Pull the fire alarm station. If it is safe and you are trained to do so, use the correct fire extinguisher to put out the fire. Begin evacuation procedures as described below. Once evacuated, inform the authorities of the location and nature of the fire, the unsafe exits, persons requiring existence and other pertinent details. Remain available to the responding security agents to provide details for the incident report.
In the event of a fire alarm in your building : Secure any hazardous materials before leaving and perform any required equipments shutdown procedures. Evacuate the premises in a swift, orderly fashion using the nearest safe exit. DO NOT use the elevators. Follow the instructions of the evacuation team. Provide assistance to persons with disabilities or with special needs. Move completely away from the building. Go to the designated meeting point, as directed by the evacuation team, or move at least 100 metres away from building.
APPLIANCES SYMBOLS IN ESCAPE ROUTE FOR A BUILDING
Emergency Symbol
Emergency Action Plan
LOSSES CAUSED BY FIRE Loss of life Affected economic growth Damage to property Injuries
Fire in residential area
WHY FIRE SAFETY IMPORTANT IN THE BUILDING? Fire safety is of the highest importance in any building, to ensure safety of OUR COMMUNITY and the protection of building. Fire protection systems and procedures are a legal requirement and need to be put in place in buildings to make COMMUNITY aware in the event of a fire.
FIRE PREVENTIVE MEASUREMENT Fire preventive measures is to prevent an actual fire accident from happening. General safety measures in establishing and maintaining fire protection: Never pile or lay material in a way that it covers or blocks access to firefighting equipment. Make sure to use only approved containers for the separation and disposal of combustible refuse. Remember to always replace the lid. Never store flammable materials within 10 feet of a building structure. Stack and pile all materials in orderly and stable piles. Never let unnecessary combustible materials get accumulated. Make a periodic clean-up of entire work site and keep grass and weeds under control. Regularly dispose of combustible debris and scrap from your work area. Use only approved containers and tanks for storage, handling and transport of combustible and flammable liquid. Always perform evaluation procedures before performing operations that present fire hazards like welding.
Causes of Fire
Fire equipment safety measures: Inspect and maintain firefighting equipment regularly. Place an adequate number of firefighting equipment in plain view in your areas. When appropriate, label the location of each one and make sure it is properly rated. Provide employees with proper training in fire prevention and protection. Prohibit smoking at or around work areas where fire hazards are present. Put up signs, saying NO SMOKING or OPEN FLAMES. Configure an alarm system that consists of both visual and audible signals (bells, sirens, whistles, blinking lights).
Fire Equipments
CHAPTER 3
TRANSPORTATION IN HIGH RISE BUILDING
CHAPTER 3 TRANSPORTATION IN HIGH RISE BUILDING Course Learning Outcome At the end of this topic students will be able to: Choose appropriate building services system with consideration of safety procedures, rules and regulation by the authority Display teamwork in completing a case study of a building services system
INTRODUCTION Transport refer to a vehicle carrying someone or something from one place to other. Transport system can usually be divided into several distribution depends on the way it moves, power and other.
TYPES AND FUNCTION There are two types transportation in high-rise building; it’s vertical and horizontal movement. Vertical and horizontal transportation means that transportation that is used to transport people and goods from one level to another for example vertical, and one point to another same level point such as horizontal. For vertical transportation consists of elevator and escalator, while for horizontal is travelator or walkway The used of this transportation will save time and energy of human being in our everyday life
Building Transportation
SCOPE OF BUILDING TRANSPORTATION SYSTEM
SCOPE OF WORK
THE THEORY Review of transport services and transport services consumer perception
THE PRACTICAL Factors to be taken into account passenger travel Position of each types of transportation Advantages and disadvantages of each type of transport
The Escalators
ESCALATOR Escalators are moving stairs used to convey people between floor levels. The maximum carrying capacity depends on the step width and conveyor speed. Standard steps widths are 600, 800 and 1000 mm , with speeds of 0.5 and 0.65 m/s. In high rise buildings space for an escalator is unjustified for the full height and the high speed of modern lifts provides for a better service.
New invented Escalator in Japan
ESCALATOR
Types of Escalators
Parallel
Criss Cross
Multi Parallel
Spiral
ELEVATOR/ LIFT “Lift” means: A lifting machine or appliance having a carrier the direction of movement of which is restricted by one or more guides A mechanized vehicle parking system, but does not include an escalator “Service lift” means a lift the rated load of which is not more than 250 kg and that has a car or cage of which the floor area is not more than 1 m2 and the height is not more than 1.2 m To function efficiently and to provide access for the elderly and disabled, modern offices and public buildings are provided with suitably designed lift installations. In large buildings it is usual to provide a group of lifts near the main entrance and single lifts at the ends of the building.
The Panorama Lift
LIFT ARRANGEMENT
TYPES OF LIFT Hospital lift
Passenger lift Trolley & Sack Barrow Lifts
Residential lift Service Lift
Platform Lift
SAFETY PROCEDURE IN HANDLING ESCALATOR Wear Safe Clothes Always Hold the Handrail Always Face Forward When standing on the escalator, Don’t Put Children in Strollers, carts, or walkers During an escalator ride, Always Secure Children When riding on escalator, Avoid the Edges of Steps When riding on the escalator Know Emergency Shut-off Buttons Never ride in the opposite direction of the escalator
Lift Maintenance Work
SAFETY PROCEDURES IN HANDLING ELEVATORS/LIFT When waiting for elevators Know your destination. Push the elevator call button once for the direction you want to go in. Look and listen for the signal announcing your car’s arrival. Be aware of health conditions that could contribute to falls or accidents. Stand clear of the elevator doors and stand aside for exiting passengers. If the arriving car is full, wait for the next car. Don’t attempt to maneuver in or stop closing doors, wait for the next car. In the event of a fire or other situation that could lead to a disruption in electrical services, take the stairs.
When boarding elevators Watch your step – the elevator car may not be perfectly level with the floor. Stand clear of the doors – keep clothes and carry-ons away from the opening. Hold children and pets firmly. Passengers nearest to the doors should move first when the car arrives. Push and hold the DOOR OPEN button if doors need to be held open, or ask someone to push the button for you. Never try to stop a closing door, wait for the next car. Once on board, quickly press the button for your floor and move to the back of the car to make room for other passengers
SAFETY PROCEDURES IN HANDLING ELEVATORS When riding elevators Hold the handrail, if available. Stand next to the elevator wall, if available. Pay attention to the floor indications. If the doors do not open when the elevator stops, push the DOOR OPEN button. iv. When exiting elevators Exit immediately at your floor. Do not wait for others behind you. Do not push the people in front of you when exiting. Watch your step – the elevator car may not be perfectly level with the floor.
Connecting Elevators
CHAPTER 4
AIR CONDITIONING SYSTEM
CHAPTER 4 AIR CONDITIONING SYSTEM Learning Outcome At the end of this topic students will be able to: Choose appropriate building services system with consideration of safety procedures, rules and regulation by the authority Identify building services system with consideration of the environmental impact Display teamwork in completing a case study of a building services system
AIR CONDITIONING SYSTEM WHAT IS AIR CONDITIONING? Air conditioning is the treatment of the air to: Control temperature Air temperature is controlled by heating or cooling the air (technically means the removal of heat, in contrast to heating, the addition of heat). Control humidity Air humidity, the water vapor contents of the air, is controlled by adding or removing water vapor from the air. Provide ventilation or air movement Air motion refers to air velocity and to where the air is distributed. It is controlled by appropriate air distributing equipment. Clean the air Air cleanliness or air quality, is controlled by either filtration, the removal of undesirable contaminants using filter or other device, or by ventilation, the introduction of outside air into the space which dilutes the concentration of contaminants. Often both filtration and ventilation are used in an installation.
BASIC PRINCIPLE IN AN AIR CONDITIONING SYSTEM Basic Operations An air conditioner is able to cool a building because it removes heat from the indoor air and transfers it outdoors. A chemical refrigerant in the system absorbs the unwanted heat and pumps it through a system of piping to the outside coil. The fan, located in the outside unit, blows outside air over the hot coil, transferring heat from the refrigerant to the outdoor air.
Air Conditioning System
The Working Principle Of An Air Conditioner Mostly Depends Upon These Five Components Evaporator An evaporator is working like a heat exchanger coil that is responsible for collecting heat within the room by a refrigerant gas, where the liquid refrigerant gas sucks heat and evaporates to become gas. Some of the commonly used refrigerant gas is R-410, R-22, and R-600A that absorbs heat inside the room and sent to the next component for further process. Compressor The compressor is an outside air conditioner unit where the compression of gaseous refrigerant occurs to propel the cold air. Condenser Condenser is also an external unit that collects vaporized refrigerant from the compressor and changes it into liquid and pushes heat outside. Expansion valve The expansion valve is situated between the two coils (the cold and hot coil) to keep tabs on the refrigerant gas. Refrigerant The refrigerant gas is the chemical that keeps the incoming air cool. It is called as Freon gas or R-22 refrigerant that is found either a liquid or gaseous form.
The Working Principle Of An Air Conditioner
Left (Centralize AC). Right (Unitary AC)
CENTRALIZED UNIT Central Plant Systems Central air conditioning is used for cooling big buildings, houses, offices, entire hotels, gyms, factories etc. A central air conditioning system is comprised of a huge compressor that has the capacity to produce hundreds of tons of air conditioning. Cooling big halls, malls, huge spaces, galleries etc. is usually only feasible with central conditioning unit There is a plant room where large compressor, condenser, thermostatic expansion valve and the evaporator are kept in the large plant room. They perform all the functions as usual similar to a typical refrigeration system. However, all these parts are larger in size and have higher capacities. The chilled is passed via the ducts to all the rooms, halls and other spaces that are to be air conditioned.
HVAC Centralized AirCond System
CENTRALIZED UNIT 1) Plant Room: The plant room is a important components. These include the compressor, condenser, thermostatic expansion valve and the evaporator or the chillier. Piping required to connect these parts 2) Air-Handing Unit (AHU) Room The air handling units are installed in the place called air handling unit rooms. The air handling units comprise of the cooling coil, air filter, the blower and the supply and return air ducts 2)The chilled water flows through the cooling coil. This cooled air passes over the air filter and is passed by the supply air ducts into the space which is to be air conditioned. The air handling unit and the ducts passing through it are insulated to reduce the loss of the cooling effect. 3) Air Conditioned Rooms: These are the rooms or spaces that are to be air conditioned. At the top of these rooms the supply and the return air ducts are laid. The supply air ducts supply the cool air to the room via one set of the diffusers, while the return air ducts absorbs the hot return air from the room by another set of the diffusers. The hot return air enters the air handling unit, gets cooled and again enters the room via supply duct to produce air conditioning effect.
CENTRALIZED UNIT 4) Cooling Tower: The cooling tower is used to cool the water that absorbs heat from the compressor and the condenser. When water flows through these components some water gets evaporated, to make up this loss some water is also added in the cooling tower. The cooling tower is of evaporative type. Here the water is cooled by the atmospheric air and is re-circulated through the compressor and the condenser.
Cooling Tower for Centralized Unit
SPLIT UNIT SPLIT SYSTEM A split system air conditioner splits the hot side from the cold side of the system, as in the diagram below. Outdoor unit: The outdoor unit contains a compressor and a condensing coil filled with refrigerant. A fan blows outside air over the coil, transferring thermal energy between the refrigerant and the outside air. The refrigerant is then circulated through pipes, or line set, to the indoor unit. Indoor unit: The indoor unit is made up of a coil and blower which is located inside of an air handler or furnace. The blower circulates air through the coil before it is sent back to the room.
ADVANTAGES AND DISADVANTAGES SPLIT UNIT SYSTEM Advantages: Easier to install most of split types can be quickly and easily installed. a window or wall opening is not required to install split ac units. The indoor unit can be placed on the floor, hung on wall brackets or mounted on the ceiling. The outdoor unit is obviously installed outside of the buildings. Advantages: Quiet operation The split ac units system is very quiet in comparison to other air conditioning systems. The minimization of noise is importance in rooms which require a peaceful environment Advantages: Cost effective With regards to the initial cost of purchasing split ac units it may be prudent to note that four indoor units can operate from one outdoor unit. The running costs of the split ac units are also cost effective. Split ac units are extremely energy efficient. Energy efficiency ensures that the split ac units do not work any harder than is ultimately required, thereby minimizing electrical energy consumption on an on going basis.
Advantage Simple Control The Split ac units are simple to operate and are therefore suitable for every and any individual considering the purchase of an air conditioning system. Disadvantages Sometimes unit fan becomes noisy Each unit or group of units has a filter, compressor and refrigeration pipework that needs periodic maintenance and possible re charging. Units have course filters therefore filtration is not as good as with AHU’s. The installation may require long runs of refrigerant pipework which, if it leaks into the building, can be difficult to remedy Not at robust as central plant. The majority of room air conditioners just recirculate air in a room with no fresh air supply although most manufacturers make units with fresh air capability. Cooling output is limited to about 9 kW maximum per unit; therefore many units would be required to cool rooms with high heat gains.
FACTORS TO CONSIDER WHEN CHOOSING AN AC SYSTEM Efficiency & Cost Comfort & Practicality Reliability Type of air conditioner Size of house/room Cost of an air conditioning system Installment and maintenance services
PRODUCT OF ENVIRONMENTAL FRIENDLY AIR CONDITIONER ACSON Air Conditioner Basic Inverter R410A 2.0HP A5WMY20S_FI + ECO COOL + Plusma Sharp R32 J-Tech Inverter AHX9VED2 &amp AUX9VED2 1.0hp Inverter Split Air Conditioner R32 Aircond PANASONIC X-DELUXE R32 Inverter XPU10WKH 5 STAR ENERGY Saving Nanoe Technology Aircond with Air Puri Sharp R32 J-Tech Standard Inverter Aircond AHX24VED & AUX24VED 2.5hp Air Conditioner Sharp R32 Inverter Samsung 1.5HP S-Essential Air Conditioner AR12TGHQABUNME
Acson Aircond
THE EFFECT OF AIR CONDITIONING GASES TO GLOBAL WARMING
CFCs/ HFCs
Air conditioners are complex machines that are made up of many different parts which work in several ways. CFCs and HFCs are both cooling agents that are in the air conditioners which, when released, increases the holes in the ozone over time. Older air conditioners rely on CFC and HFC and contribute to global warming in a major way. Even newer models, which rely more on HFCs and HFOs play a large role in ozone depletion. Energy use Air conditioners require lots of energy to function properly. It consumes so much electricity and therefore releases pollution. When fossil fuel is burned, carbon dioxide is also released into the air, more commonly known as a greenhouse gas, which is a major contribution to ozone depletion. The average and typical air conditioner will consume about 3000 to 5000 watts of electricity every hour, depending on the season – the warmer, the more power used. This is clearly very harmful to the environment, as well as extremely expensive.
Global Warming Effect
THE EFFECT OF AIR CONDITIONING GASES TO GLOBAL WARMING Unclean ducts It is important to note that air conditioners do not only affect the environment in a global way, it also affects it on a small scale as well. The ducts in each air conditioner, over time, collect dust and bacteria and every time the air conditioner is turned on, both are released, and are toxic for humans, especially children. There are ductless mini-split brands though that focus more on the environment and safety of people. Ductless mini-split brands are actually more durable and work in warmer climates such as Middle East, Asia and Central and South America. Materials used In the past air conditioners were mainly made out of metals. Though over the years, people decided that metal is too expensive and too heavy, so they opted for plastic. Although metal and plastic are both harmful to the environment, plastic is completely non-biodegradable, which makes it an enemy of the environment. The production of plastic alone is extremely detrimental, as it too releases carbon dioxide into the air and causes what we now know as the greenhouse effect.
CHAPTER 5
MAINTENANCE WORKS
CHAPTER 5 Maintenance Works Learning Outcome At the end of this topic students will be able to: Choose appropriate building services system with consideration of safety procedures, rules and regulations by the authority Display teamwork in completing a case study of a building services system
INTRODUCTION All element of buildings deteriorate at a greater or lesser rate depending on materials and methods of construction, environmental conditions and the use of the building.
MAINTENANCE CONCEPT Maintenance is done to maintain all facilities in an acceptable condition. Acceptable condition means that the facility is ready for use after repair. BS38811: maintenance is defined as all technical and administrative measures taken to preserve or improve the things that matter to fulfil its intended function.
BUILDING MAINTENANCE CATEGORIES BS 3811 Planned maintenance Unplanned maintenance Preventive maintenance Corrective maintenance Emergency maintenance Condition – based maintenance Scheduled maintenance
TYPES OF MAINTENANCE
MAINTENANCE SCHEDULE
Monthly Maintenance Schedule
Annual Maintenance Schedule
COMPARISON BETWEEN PREVENTIVE & CORRECTIVE MAINTENANCE Preventive Maintenance The maintenance carried out at predetermined interval or corresponding to prescribed criteria and intended to reduce the probability of failure or the performance degredation of an item.
Corrective Maintenance Carried out after a failure has occured and intended to restore an item to a state in which it can perform its requuired function
THE ADVANTAGES Preventive Maintenance Carried out to prevent an item failing or wearing out by providing systematic inspection, detection and prevention of incipient failure.
Corrective Maintenance Carried out on all items where the consequences of failure or wearing out are not significant and the cost of this maintenance is not greater than preventive maintenance.
Preventive Maintenance
REFERENCES R.C Mishra (2012). Maintenance Engineering and management (Second Edition). India: Ninth Printing. Richard J. Diven (2010). Demolition, Practice, Technology & Management, United States: Purdue University Press Egan M David, (1986). The Building Fire Safety Concept. Skudai, Malaysia: University Technology Malaysia. Fullerton R. L. (1979). Building Construction in Warm Climates. (Volume 1, 2, 3). United Kingdom: Oxford University Press. Hall F. (2000). Building Services & Equipment, England: Pearson Limited MDC Legal Advisers (1996) Uniform Building By-laws 1984. Malaysia: MDC Publishers Printers. Roger W. Haines (2006). Control System for Heating, Ventilating And Air Conditioning, New York Inc: Springer-Verlag.
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