FIRE PROTECTION AND SYSTEMS Fire protection system Definition - Fire protection system is a system that includes devices, wiring, piping, equipment and controls to detect a fire or smoke, to actuate a signal, and to suppress the fire or smoke. Main objectives of fire protection system • To save lives • To protect property • To minimize interruptions of services due to the outbreak of fire Factors which influence the cost of fire protection system • The fire resistivity of the building • The type of occupancy • The number of floors below the ground level • The height of the building • Adequacy of escape routes or way outs • The degree of protection desired Classes of fire Class A - fires of ordinary combustible materials, such as wood, cloth, paper, rubber and many plastics Method of extinguishing - water, water based chemicals, dry chemicals, carbon dioxide Class B - fires due to inflammable liquids, oils, greases, tars, oil-base paints, lacquers, and flammable gases Method of extinguishing - form, dry chemicals Class C - fires that involve energized electrical equipments Method of extinguishing - using electrically non-conductive chemicals, multipurpose chemical compounds, carbon dioxide agents Class D - fires due to combustible metals, such as magnesium, titanium, zirconium, sodium, lithium, and potassium Method of extinguishing - using heat-absorbing extinguishing medium: medium: purple k, monnex, super k
Passive fire-fighting system It means the design of the building, its structure, fabric, components and their installations in order to resist fire.
Factors that influence Passive fire-fighting system • BOMBA requirements - i.e. fire department or fire fighting fi ghting accessibility • Uniform Building Bye Laws (MBBL) - part VII (fire requirements) e.g. grouping of buildings, compartmentalization compartmentalization within the t he building, fire resistance, planning of escape routes. • Local authority requirements - e.g. City Hall, Kajang Municipal Council, Shah Alam City Council, Subang Jaya Municipal Council • Building insurance companies' requirements - minimum legislative standard • etc
Active fire-fighting system This refers to fixed or portable equipment installed or incorporated into the building for the purpose of resisting fire during the out break of fire. So the installation of Active fire-fighting equipments in the building has two main functions:• detection of fire • suppression of fire Active fire-fighting system This refers to fixed or portable equipment installed or incorporated into the building for the purpose of resisting fire during the out break of fire. So the installation of Active fire-fighting equipments in the building has two main functions:• detection of fire • suppression of fire Types of Active fire-fighting system • Portable fire extinguishers • Automatic fire extinguishers • Hose reel and Hydrants • Automatic extinguisher systems • Pressurized escape routes • Smoke extraction and ventilation Automatic fire alarm detectors • Bimetallic strip • Ionization chamber • Light-scattering devices • Laser beams Hose reel and Hydrants • Hose reel • Hydrants: Internal Hydrants, External Hydrants • Dry riser • Wet riser • Form installation Automatic extinguisher systems • Gas extinguisher system • Water sprinkler system • Wet sprinkler • Dry sprinkler • Alternate wet and dry sprinkler • Tail-end sprinkler • Pre-action sprinkler • Recycling sprinkler Smoke extraction and ventilation • Vents • Shop extract and smoke control • Shop extractor • Mall extractor
In general, the basic elements or components of a fire-fighting system are:• Water supply • Water pump • Fire mains hydrants • Portable fire extinguishers • Fire monitors • Fixed water sprays • Live hose • Fire hoses • Fire forms Difference between Dry riser and Wet riser Dry riser - is a vertical pipe which is dry (without water) and with hydrant valve attached and located at each floor. This vertical pipe shall function only when the fire department channels water through it during the outbreak of fire Wet riser - is a vertical pipe which is always full of water. Its function is to supply water to the hydrant valve located at each floor of a tall (high-rise) building, when there is a fire Shop extractor and Mall extractor: are two types of fire protection system in a shopping central complex Shop extractor - is a method of smoke and fire containment in a shop-lot unit. It is controlled by the tenant or the shop-lot keeper. Mall extractor - is a common smoke collection and containment reservoir at the height (on top) of a mall. It is controlled by the building owner. FIRE DETACTORS Basic principles of fire detectors • Reaction to heat • Radiation to flames • Products of combustion Main function of fire detectors • To give warning that a fire has taken place in unattended places • To activate automatic fire-fighting equipments Common types of fire detectors There are several groups of fire detectors • Group I - detectors for hazardous situations • Group II - ionization smoke detectors • Group III - visible smoke detectors • Group IV - heat detectors
In general we say common fire detectors are: Heat detectors Smoke detectors • •
Essential ingredients of fire: Fuel, Heat, Oxygen The system of fire-fighting employed depends on: • The total combustible content of the building • The type of fire risk classification • The degree of involvement by the occupants Important terms related to fire: Fire door: - a door assembly that provides protection against the passage of fire Fire wall: - fire resistant wall that extends continuously from the foundation of the building up to or through the roof. Fire walls are related in hours, depending on the use of the building and the "fire separation distance", required fire resistance ratings vary from 1 hour to 4 hours Fire separation distance: - the distance in feet or meters measured from the face of a building to the adjacent building or the nearest public path/walkway. Fire partition: - refers to the vertical assembly of a wall material designed to limit the spread of a fire. The overall assembly shall have a fire resistance rating (in hours) equal to a greater than that specified in the governing code. Depending on the use of the building and whether it has a sprinkler system, a fire partition shall have a rating up to 2 hours. Apparent ignition temperature: - is the temperature required to begin or cause burning at a rate which is sufficiently rapid so that the burning will continue when the heat source is removed. Combustion: - is a chemical process that involves oxidation sufficient to produce heat and light Explosion: - is the result of rapid combustion with a sudden, violent change of pressure involving the liberation and expansion of a large volume of gas. Smoke detectors and Automatic sprinkler. Introduction: • Fire detections are an active fire protection measure subject to stringent buildings • They are connected to a fire suppression system that consists of over head pipes fitt ed with sprinkler heads throughout the coverage area • Fire detection systems for high-rises are usually also equipped with a fire pump and a jockey pump and are tied into the fire alarm system. • Although historically only used in factories and large commercial buildings, home and small building systems are now available at a relatively cost effective price. Based on the buildings functions and occupancy, there exist various types of sprinkler systems. • Wet sprinkler • Dry sprinkler • Alternate wet and dry sprinkler • Tail-end sprinkler • Pre-action sprinkler • Recycling sprinkler Usage • Sprinklers required in all new high rise and under ground buildings generally 75 feet (23 m) above or below fire department access
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Sprinklers may also be required in hazardous storage spaces by building codes or may be required by insurance companies where liability due to potential property losses or business interruptions can be reduced by adequate automatic fire protection. Building codes for places of assembly, generally over 100 persons and places with overnight sleeping accommodations such as hotels, nursing homes, dormitories, and hospitals usually require sprinklers to fight, and subsequently suppress high challenge type fires
Water sprinkler • To control outbreak of fire • Sprinkler head can be attached to rising main supply • Types of sprinkler head Fusible link sprinkler head Glass bulb sprinkler head Chemical sprinkler head Open sprinkler head Glass bulb sprinkler head • Valve firmly seated by a sealed glass tube containing colored volatile fluid that expends with heat to burst tube and release water from pipe work. • Fluid operating temperature based on color codes Fusible link sprinkler head • The lever is retained in position by solder that melts with heat change • Once the solder melts the lever will spring apart to release water
HEALTH AND SAFETY Safety: is the state of being relatively free from harm, danger, injury or damage. Danger. A situation which is capable cause injury to someone and destroy a property. Accident: A happening or an event which is not expected foreseen or intended. Why safety at the workplace is important? Safety at work place is important because: • People place high value on life because life is very priceless • Fear of loss of property • Fear of economic loss • Fear of injury Occupational Safety and Health Act 1994 (OSHA 1994) Occupational Safety and Health Act 1994 (OSHA 1994) enforced since 25 February 1994 Main objectives of OSHA 1994 • To promote safety and health commitment among all employers and employees • To establish effective safety organization and arrangements at the workplace Long term goal of OSHA 1994 • To create a healthy and safe working culture among all Malaysian employers and employees
Industrial sectors covered by OSHA 1994 Manufacturing Mining and Quarrying Construction Agriculture, Forestry and Fishery Utility: Electricity, Water, Gas, and Sanitary services Transport, Storage and Communication Wholesale and Retail Traders Hotels and Restaurants Finance, Insurance, Real estate and Business services Public services and Statuary Authorities Basic Philosophy of OSHA 1994 "Self-regulation" which means that the responsibility of ensuring safety and health at the work place lies with those who create the risks and with those who work with the risk. Some of the more important provisions of OSHA of 1994 General duties Provisions related to the general duties of employers, employees, self-employed, designers, manufacturers, importers and suppliers of plant and substances are clearly defined under the act. The main duties are summarized as follows Duties of an employer: Employers must safe guard so far as is practicable the safety, health and welfare of the people who work for them. This act outlines five (5) specific measures or steps to be taken by an employer so far as is practicable in order to safeguard the safety, health and welfare of their employees. To provide and maintain the plant and safety systems of work that are safe and without risks to health. To make arrangements for ensuring safety and health in connections with the use of operations, handling storage and transport of plants and substances. To provide information, instruction, training and supervision to ensure employees to perform their work in a safe manner and without risk to health. To maintain a workplace that is safe and without risks to health, including means of access and egress (layout). To provide and maintain a working environment that is safe and and without risks to health with adequate welfare facilities. Definitions:- Plant: means any machinery, equipment, appliance, implement or tool, any component there of and anything fitted, connected or appurtenant there to. Substance: means any natural or artificial substance, whether in solid or liquid forms or in the form of a gas or vapor or any combination there of. So far as is practicable : is an important clause before an employer could discharge his duties/responsibilities. The factors that he needs to consider are: The severity of the hazard or risk in question The state of knowledge about the hazard or risk The availability and suitability of ways to remove or mitigate the hazards or r isks The cost of removing or mitigating the hazard or risks
Safety and Health Committee When to establish this committee? • When the organization has 40 or more than 40 employees • When it is being directed by the Director General or Department of Occupational Safety and Health Main functions of Safety and Health Committee • To monitor safety measures taken at the work place • To investigate any accident and related matters arising at the work place • To act as a platform for consultation between the employer and employees in matters related to safety and health at the work place Committee members in the Safety and Health Committee Chairman (chair person) Representative of the employees Representative of the employer Secretary (normally is the safety and health officer) Definitions Unsafe Acts: are acts which may cause or lead to danger or harm to oneself as well as to others. e.g. • Fooling around • Smoking in "no smoking area" • Not completing a routine checklist • Not wearing a proper personal protective equipments • Climbing a ladder with broken rungs, etc Unsafe Situations: refers to any situation or condition that may cause or lead to danger or harm to oneself as well as to others. e.g. • Working on slippery or very rough floors • Falling and flying objects
PLUMBING EQUIPMENTS AND SYSTEMS
Domestic water supply Water is very important for all forms of life. Basically there are two system of water supply to our homes. They are • Direct system • Indirect system Direct system • Supplies water directly to our homes (houses) through service pipes Indirect system • Supplies water to our homes (houses) through a water tank • From the water tank the water is supplied through various piping devices. E.g. communication pipes and distribution pipes
Important related definitions Service pipe: this pipe connects the water to the water tank and piping to the kitchen Communication pipe: this pipe connects the main pipe with the water meter Distribution pipe: this pipe supplies water from the water tank to the piping equipments in the house like sinks, wash basins and showers Scour pipe: this pipe is installed at the base of the water tank. Its function is to let water flow out of the water tank during cleaning or maintenance works Overflow pipe: this pipe is fixed slightly above the full water mark of the water tank. Its diameter size is bigger than that of the service pipe. Its function is to let overflow when the ball valve is malfunctioned or damaged. Comparison between direct water supply and indirect water supply Direct water supply Less pipe work and smaller storage cistern, making it cheaper to install. Drinking water available at the wash basins or kitchen sink Smaller cold water cisterns which may be sited below the ceiling Indirect water supply Large capacity storage cisterns, providing a reserve of water during failure of the main supply The water pressure on the taps supplied from the cisterns is reduced, which minimizes noise and wear on the taps Fittings supplied with water from the cistern are prevented from causing contamination of the drinking water by back siphonage Taps, valves and cocks are terms used indiscriminately to name fittings required to control the flow of water (or the fluids), either along or at the end of a pipeline. Valves: are usually used to control the flow along a pipeline Taps: are used at the end of a pipeline for draw off purposes Cocks: consist of a body holding a tapered plug. The plug has a hole cast or drilled in the middle through which the water can flow. The cock can be fully opened or full y closed by turning the plug through an angle of 45° (or quarter turn). It can be closed very quickly and may cause a water hammer. Plumbing Fixtures and Plumbing Appliance Plumbing fixtures refers to a receptacle for waste, which are ultimately discharged into the sanitary drainage system. Examples: Water closet, Urinal, Wash basin, etc. Plumbing appliance refers to a special class of plumbing fixtures intended to perform a special function. Examples: Bath tub, Shower head, Kitchen sink, etc. Materials used for plumbing fixtures and appliances • PVC (poly vinyl chloride), Cast iron, Enameled pressed steel, Stainless steel, Fiber glass, Plastic, Terrazzo andCement, etc Water closet • It is water flushed plumbing fixture designed to receive human waste directly from the user. • Water closets are rated at 6 drainage fixture units of waste discharge and require a 75mm waste pipe and a 50mm vent.
Urinal • It is water flushed plumbing fixture designed to receive urine directly. • Urinals are manufactured from vitreous china or enameled cast iron. • Urinals, like water closets, are available with a variety of different flushing actions: washout, siphon jet and blowout. Wash basin • It is a plumbing fixture designed for washing of the hands and face. • It is commonly found in bathrooms and restrooms or toilets. • Wash basins are sometimes called vanity lavatories • They are rated at 1 drainage fixture unit of waste discharge and require a 31mm vent pipe. • Wash basins are commonly made from vitreous china, enameled cast iron, enameled pressed steels, stainless steel and plastics. • Various models are available, e.g. wall-hung, vanity and vanity-top Bath tub • It is a receptacle for water that is shaped to fit a human body and is used for bathing. • Bath tubs are rated at 2 drainage fixture unit of waste discharge and require a 38mm waste pipe and a 31mm vent pipe • Bath tubes are identified as right hand or left hand according to the location of the tub waste opening. A right hand bathtub has a drain on the right end of the tub as you face the length of the tub. A left hand bath tub has the drain on the left. • Bath tubs are manufactured from enameled. That is enameled pressed steel, and fiberglass in a variety of shapes, sizes and colors. Kitchen sink • It is a shallow, flat bottomed plumbing fixture used in cleaning dishes and in connection with food preparations. • Kitchen sinks are related at 2 drainage fixture units of waste discharge and require a 38mm waste pipe and 31mm vent pipe. • Kitchen sinks are available in various sizes and shapes. The most popular is the double-compartment double-bowl type, installed on a kitchen cabinet counter top. • Kitchen sinks are manufactured from enameled. That is enameled pressed steel and stainless steel. Direct system of water supply Advantages • Water supplied is clean and fresh • Water pressure supplied is high • With this system, losses can be overcome because it does not undergo overflow at the water storage tank • Water storage tank is not to be provided Disadvantages • If damage occurs at the main pipe, the main valve shall be closed, hence the water supply to the entire building shall be disrupted • Damage or leakage is quite difficult to be detected • There is no water supply kept if there is water disruption
Indirect system of water supply Advantages • If there is disruption to the water supply, there is still water supply for a period of 12 to 24 hours • Loading to the main pipe can be lightened during peak demand • Water supply is always constant • If damage occurs to any of the sanitary equipment fixtures, only nearest valve shall be closed, hence the water supply to the remaining sanitary fixtures can continue. Disadvantages • Water storage tank and its space for positioning need to be provided • Water supplied from the storage tank may not be that clean. Contamination may be due to the storage tank itself. E.g. from joints/connections, rust, etc • Water wastage may happen if the ball valve at the storage tank is not f unctioning • The provision of water storage tank need to comply to the rules/requirements of the relevant authorities • Water supply will be disrupted when the storage tank is being cleaned or when maintenance work is in operation. Direct system Supply fresh and clean water to bathrooms and kitchen Lack constant water pressure, therefore may require pump Inconsistent water supply, especially when water cut or rationing occurs Inexpensive because less pipe work, and no storage tank Only suitable for low-rise buildings which require low water pressure Any defect in the pipe work can cause water cut to the system Indirect system Supply fresh water to the bathrooms and wash basins only Constant water pressure and does not require pump Constant water due to provision of storage tank Expensive because more pipe work, and need storage tank Suitable for high-rise buildings Defect to the service pipe does not effect the entire system because it can be segregated by valves MECHANICAL AND ELECTRICAL SYSTEM Mechanical and Electrical system for buildings
Modern buildings must be designed with features to provide; Better lighting Comfortable space/room temperature Humidity Air quality Convenient power and communication capabilities High quality sanitation Reliable systems • • • • • • •
ALL the above features are needed for the protection of life and property. All these desirable features have become a reality with recent advances in the technology of Mechanical and Electrical system. These advances have open the door for a wide range of architectural design innovations in style, form and scope that are not achievable without the utilization of Mechanical and Electrical system. Block type without windows such as departmental stores are totally dependent on electrical lighting, ventilation and space/room condition. High-rise buildings must rely on high-speed vertical transportation and high-pressure water for drinking and cleaning purposes and for protection against fire. Mechanical and Electrical systems demand considerable floor and ceiling space. Without proper space allocation during the preliminary planning phase of a building project, the design process may have to be started all over again, and often the system performance are compromised. Furthermore in some cases Mechanical and Electrical systems add to the cost of construction of a building, exceeding 50% of the total cost. Examples are sophisticated buildings such as research buildings, hospitals with update facilities, computer centers, etc. Mechanical and Electrical systems also r equire energy to operate them. Energy consumed by occupied buildings, including residential, commercial, industrial, institutional facilities accounts for over 50% of all energy usage by an industrialized country. Energy also accounts for a large portion of the operating costs of such buildings. Properly designed Mechanical and Electrical system will utilize space and energy efficiency, thereby reducing building costs and minimizing environmental impacts. Categories of Mechanical and Electrical systems
For modern buildings, Mechanical and Electrical systems are classified into three (3) major categories: Mechanical systems •
HVAC- referring to heating, ventilating, and air-conditioning. The components of HVAC system in the mechanical and electrical system for a building are: HVAC delivery Cooling production Heating production Air handling Piping systems Site utilities- referring water supply, storm (surface) water drainage, sanitary disposal, gas supply Plumbing- referring to water distribution, water treatment, sanitary facilities, etc Fire protection- water supply, stand pipes, fire and smoke detectors, automatic sprinklers, etc Special systems • • • • •
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Electrical systems • Electrical power- normal, stand by, emergency power supply and distribution • Lighting- interior, exterior and emergency lighting • Auxiliary- telephone, signal, data, audio/video, sound, fire alarm, security systems, etc • Special systems
Building operation systems • Transportation- refers to elevators, lifts, escalators, moving walkways, etc • Processing- production, food services, etc • Automation- environmental controls, management, etc • Special systems. The impact on space planning The floor area necessary for Mechanical and Electrical systems in a building varies widely, depending on; • The occupancy • Climatic conditions • Living standards • Quality and general architectural design of buildings
The Mechanical and Electrical space affects the gross floor area, the size and the shape of the building's ground floor, floor-to-floor height, geometry and architectural expressions Reasonable allocations made during the space planning phase allow Mechanical and Electrical space to be approximately sized and strategically located.
AIR CONDITIONING SYSTEM
What is "Air-conditioning"? It is the process of controlling and treatment of all the air contents in a room or enclosed space. Mechanical treatment is conducted on the temperature, air humidity, and cleanliness and air distribution in order to obtain the requirements and functions of a particular room or enclosed space. Main functions on Air-conditioning system • Temperature control by heating and cooling • Humidity control by humidification or dehumidification • Cleanliness control by filtration cleaning and absorption in order to remove dirt's or contamination. • Air distribution, i.e. type of ventilation and type of air flow. Basic cycles of an Air-conditioning system
There are two basic cycles: Cooling cycle: transfer of heat from one place to another place Air cycle:- The use of air as a refrigerant is based on the principle that when a gas expands adiabatically from a given temperature • •
Main components of cooling cycle Compressor • • Is the heart of the cooling system • It increases the pressure of the "refrigerant" and pumps it the condenser/entire cycle. • Condenser • Remove heat from refrigerant which is in high pressure gas form
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Refrigerant • Absorbs or remove heat • It can condense or evaporate at low temperature Expansion valve • Controls pressure and rate of entry of refrigerant to the evaporator unit Evaporator • Absorbs heat from the surrounding (i.e. space of room which is being cooled Thermostat • Controls cooling temperature as required
What is the name of the refrigerant? • Freon gas The processes which occur in the "refrigerant cycle" of an air-conditioning unit are: • Freon gas is compacted at the compressor unit to increase the boiling point. This causes the pressure of the Freon gas to increase • This high pressure gases will slowly change into a liquid at the condenser unit. • There is a fan which functions to cool the condenser unit. This fan is required because the coil at the condenser got heated due to heat produced from the change process of the gas into the liquid • The high pressure liquid shall pass through the expansion valve. Here the expansion valve will function to lower the pressure of the liquid. The boiling point of the liquid will decrease when the pressure is lowered. • The liquid whose boiling point has been lowered shall pass through an evaporator unit. There exist a cooling coil at this unit • Here, the liquid will slowly changes into a gas. During this changing process heat is absorbed and this cools down the coil. • There is also a blower at the evaporator unit. This blower serves to " suck in" air from the room/space. This air shall become cold when it passes through the cooling coil of the evaporator. This cold air shall be "blown out" by the blower through the air supply grills. • With this, cold air can be supplied to the room/space which needs to be cooled. This process shall be repeated and the air can be cooled continuously Components of air cycle Fan • To move air inside the space/room. (all outside air, all inside air within the roomrecycling, contamination of outside air) Supply duct • Direct air from the fan into the room/space Supply outlets • Distributes air uniformly inside the room/space Space to be cooled • Allows air within space/room to enter the return ducts. (OR. Allows air to escape from the space or room Return air ducts • Transports used air to the filter Filter • Filters are before being distributed for the following purposes.
Protects health and comfort of the occupiers of the room. Keeps the cleanliness of the surface and furniture of the room Protects equipments especially sensitive ones like PC, etc Protects devices within the air conditioning unit Cooling air Absorbs heat from the room or space in order to obtain comfortable temperature. •
Factors that influence on the choice of Air-conditioning system for any building • Space size • Space layout • Space utilization • Capacity in the room Space size: The space (room) size needs to be known in order to determine the heat loads and the capacity of the air-conditioning units to be used in that r oom (enclosed space) Space layout: Need to know whether the spaces (rooms) are grouped together or are distant apart. If the rooms are grouped (close to each other), a centralized system is more suitable. If the rooms are distant apart, centralized system is not economical because it will require the use of longer ducting Space utilization: Space (or rooms) utilization can be divided into three: Utilization by time: There exist spaces (or rooms) which are utilized on different "timings". E.g. rooms in hotels Utilization by surrounding environment: Spaces (or rooms) within the building require different temperature and humidity. E.g. rooms for museum, showrooms, and laboratories Activities inside (human activities): Different activities within the room create different situations. E.g. a sports club requires extra ventilation compared to that of recreation or leisure rooms. A suitable temperature will depend on the requirements of the occupants as well as on the equipments present in that room. E.g. electrical devices (computer components), height that emit extra heat, etc Capacity in the space (room): This refers to human capacity or occupancy inside the rooms within the building. Types of Air-conditioning systems 1. Unitary system • This type of air-conditioning unit is used to cool the air at specific sections of rooms within the building (or house). E.g. to cool a particular room or various rooms within the building • A single unit of this system can be used to cool more than one room • There exist three types of this unitary system window type split type multi-split type
Unitary system / window type • This system is suitable for rooms or offices which have part of the wall outside. This is because some section of the unit is installed outside • The wall where this unit is to be installed has to be drilled first • The initial cost of installation of this unit is rather high. Unitary system / split type • For this system there exist two units: one unit is placed inside the building and another unit is placed outside the building • The indoor unit consists of the evaporator • The outside unit consists of the compressor, condenser and the expansion valve/capillary tube • This split type consists of four models Ceiling mounted Ceiling suspended Wall mounted Floor mounted Unitary system / multi-split type • This system is used to cool more than one room • Only the outdoor unit is being used • The total indoor units depend on the total number of rooms which need to be cooled • The indoor unit can be selected from the type available in the split unit discussed earlier.
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A central air-conditioning system is used to cool the air for the entire building The equipments for a central air-conditioning system are large and capable of cooling large spaces (or rooms) This system requires the use of ducts. Ducts shall carry the cooled air produced from the air-conditioning plant to the enclosed spaces (rooms) that need to be cooled inside the building. Usually the ducts (or ducting) are installed above the ceiling within the building In the central system, there are two methods of how the condenser units are cooled: Air cooled Water cooled
Advantages of split type of air-conditioning system • Easy to be installed for completed buildings either for minor or medium requirements • Good appearance of the indoor units (can be located anywhere within the room or enclosed spaces) • The units which uses air ducts are suitable for lecture rooms, meeting/conference rooms, halls and laboratories provided humidity requirements have no objection • Quite. (The compressor unit is located at the outdoor unit outside the building). Ventilation Ventilation is any air circulation or air movement within a building. It is a process to maintain a comfortable environment on temperature, humidity, and oxygen in an enclosed space (or rooms) by having clean air flowing from one room to another room
in order to replace contaminated or used air inside that room. Ventilation is measured in air volume. Purposes of ventilation In general the main purpose of ventilation is to get cooling, drying, and circulation of clean air. Human requires ventilation for comfort, i.e. to remove "uneasy feelings" due to warm circulated air in the surrounding. To be more specific, ventilation: • Prevents the entry of heat from outside • Maximizes heat loss inside the enclosed space or room • Removes unpleasant odor and unclean air content, (like ducts, etc) • Prevents heat intensity machines, lightings and the occupants themselves • Reduces the increase of carbon dioxide contents and humidity within the enclosed space or room. There are two types of ventilation Natural ventilation Artificial ventilations Factors which controls or influence natural ventilation Pressure variation due to wind The "stack affect" which results from warm air in the building rising and being displaced by colder outside air Combination of pressure variation due to wind and the "stack effect" The scale used to measure wind space is called the Branford scale • Ground area where wind speeds > 5m/s - uncomfortable for human occupations • Ground area where wind speeds > 10m/s - unpleasant • Ground area where wind speeds > 20m/s - dangerous • For wind speeds < 5m/s - OK, considered as comfortable
INTRODUCTION TO ELECTRICITY Conductors Conductors are materials that allow electricity to pass through them. (Conducting materials vary in the degree to which they can conduct electricity; good conductors are required for connecting leads in electric circuits so that they may carry the current with minimum lost of voltage) Examples of conductors • Copper , Aluminum, Carbon, Brass, Eurika, Tungsten, Manganin, Nichrone, Human body The best conductor is copper Advantages of copper used. low resistance it is ductile and therefore easily formed into wires it is readily "fined" for soldering
Advantages of brass used. it is harder than copper it is easily machined it can be easily readily like copper , it is also "fined" for soldering Insulators: Insulators are materials do not allow the free passage of an electric current pass through. (insulators are used combine electric currents to the conductors in which they are intended to flow and to prevent leakage of electricity to adjacent conducting materials which are not intended to become "Alive" ) Example of insulators • wood, rubber, plastic, glass, paper, Asbestos, PVC, Mineral insulation eg MgSO4 , Mica, paxolin, bakelite, etc: Rubber is the best insulator Often used as covering for cables and wires for following reasons, • Impervious to water • Being good insulation • Flexible Some disadvantages of rubber. • Not fire proof • Cannot resist heat • Adversely affected by sunlight Lifts : lift should be installed at strategic location . Factors that need to be considered in the proper sitting at lift are • A lift installation has an important bearing on the effi cient functioning of the building service. • To get an efficient service, the number and type of lift must take into an account, several factors including the type of building and the nature of its occupancy. • Lift should be sited in the control area. And take in to an account the proximity at entrance to the building and staircase. • If a entrance of a building are not in a central position, there is strong case for centralizing the lifts, since their use during the day may out weight the inconvenience of reaching the lifts at morning arrival and evening departure • When a building has to have a number of passenger lifts, it is usually preferable to group them together rather than spread them through out of the building. • Grouping of lifts reduces the cost of installation • If passengers have to pass a staircase on the way to a lift the demand on the lift tends to be reduced, if they pass a lift before reaching a staircase, the demand on the lift tends to be increased. Factors that influence the number and size of lift for building • Population of the building • Type of building occupancy • The starting and finishing time of the population whether staggered • The number of floors and heights • The position of building in relation to the public tr ansport service.
Note: the choice, numbers and sizes of lifts usually lies between the convenience of the user and the overall building loading times, and a compromise is usually required to obtain safe factory balance between those 2 factors. Several small lifts will provide a better service than larger lifts but the installation cost of the lift is lower. Escalators: • Are continuous conveyer designed for moving large number of people quickly and effectively from one floor to another. • Unlike a normal lift installation, if requires no waiting time and order to get a similar service, a large number of lifts occupancy more floor space would be required. • It have advantages of being reversible to suit the main floor of t raffic during peak time and unlike lifts, they may be used when stationary Usage of Escalators Bank, departmental stories, sport stadium, exhibition halls airport terminal, railway station. The carrying capacity depend on the speed along the line of inclination and the width of the thread 0.45m/s to 0.1m/s Variable influencing the comfort of the occupants of building are . temperature … humidity …airflow ..air quality ..radiation .. lighting .. Factors affecting the effectiveness of building design 1. Net floor area (NFA). 2. Net to gross ratio (NGR). 3. Floor efficiency ratio (FER). 4. VSR. 5. APR 1. Net floor area (NFA). It is the floor area that can be used by the occupants and is some times referred as net design area. Net floor area typically defined as the gross floor area excluding the area taken bye stairs, circulation space, lobbies, structural columns, M&E equipments. 2. Net to gross ratio (NGR). NGR=100 X NFA/GFA The available NGA depends on the building occupancy, M&E system and architectural design and usually range between 60-90% FER = 100 X NRA/GFA , where NFA is net floor area /GFA is gross floor area.sq.m. 3. Floor efficiency ratio (FER) The floor efficiency ratio is frequency used for office building to calculate the rentable space on typical rental floor. FER=100 X NRA/GFA 4. VSR VSR=V/s where v is volume of the building / s is total external surface area of the building. 5. APR APR= A/P where A is typical or representative floor area of building , P is linear dimension of perimeter of a typical floor.
