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1) Types of split air conditioning system known to you

Split Connects one indoor unit to an outdoor unit. Installs simply and unobtrusively to buildings with no need for ductwork. Delivers a sophisticated air conditioning solution to single zone interior spaces at an affordable price. Provides a simple solution for one-room additions.

Multi-split Connects up to five indoor units to a single outdoor unit. Installs a complete air conditioning system to multiple zone interior spaces with no need for ductwork. Provides individual control of room temperature settings. Enables indoor units of different styles and capacities in one system for customized solutions unique to each resident setting.

2) types of fire detectorsFire detectors are designed to respond at an early stage to one more of the four major characteristics of combustion, heat, smoke, flame or gas. Detectors should be chosen for the best response to the effects of fires, as well the need to minimise unwanted false alarm activations. Detectors should be located where the early stages of fire will be detected, and ensure they are placed at regular intervals on the ceiling. The issue of unwanted fire alarm activations from environmental conditions must also be considered Heat detectors Heat detectors respond to the temperature rise associated with a fire. Ionisation Smoke detectors Ionisation smoke detectors respond to very small smoke particles a wide range of responses. Photo-electric smoke detectors Photo-electric smoke detectors measure the scattered light from smoke particles. Linear beam smoke detectors Linear beam smoke detectors measure the reduction of intensity of a beam of light due to the presence of smoke particles. Aspirated smoke detectors Aspiring-type systems eg (Vesda Systems) are more effective in detecting smoke than point type detectors in many applications

3) importance and location of A.H.U.

Air handling Unit (AHU) is a heat exchanger, where air is treated to bring it to comfortable conditions. In addition to thermally treating air, it is also filtered by passing it through filter banks and mixed with outside fresh air in AHU mixing chamber. This provides required ventilation air for inside environment. Each unit is necessarily provided with a heat exchanger called cooling coil and filter bank, in addition to a fan which is required to move the air through this assembly as well as associated ducting network. Supply air either recirculated or fresh, passes through these two components.As the air passes through coils and filters. it carries with it a range of contaminants, including dust, micro-organisms and hydrocarbon fumes. These contaminants are circulated through the system several hundred times a day. The damp cooling coil surface provides a plentiful supply of both nutrients and water, producing an ideal environment for micro-organisms to proliferate. They may be mounted on the top of the roof or in large mechanical rooms located in the building. They often have an economizer or inlet damper that allows for a small amount of outside air or make-up air to be pulled in through the air handler.

4) wet riser and wet riser cum down comer

Wet risers are used to supply water within buildings for fire-fighting purposes. The provision of a built-in water distribution system means that fire fighters do not need to create their own distribution system in order to fight a fire and avoids the breaching of fire compartments by running hose lines between them.Wet risers are permanently charged with water. This is as opposed to dry risers which do not contain water when they are not being used, but are charged with water by fire service pumping appliances when necessary.Wet risers are charged with water from a pressurised supply, often pumped from a storage tank, with landing valves at specified locations on each floor.Wet risers should be within fire-fighting shafts, and where necessary in protected escape stairs. Wet-riser outlets, or 'landing valves' may be within in protected lobbies, stairs or enclosures where these are available.Wet risers should be inspected and tested regularly to ensure equipment is functioning correctly and ready for use. Problems can be very serious in the event of a fire, and are typically caused by vandalism or theft, blockages or pipework failure or by connection failure or outlets being open.wet riser cum down comerAn arrangement for fire fighting within the building by means of vertical rising mains of not less than 100 mm internal dia with landing valves on each floor/landing connected to terrace tank for fire fighting purpose, through a terrace pump, gate valve and non-return valve near the tank and to a fire pump, gate and non-return valves, over the static tank.

5) the advantage of chilled water system over direct expansion of the system

In the direct expansion of central air conditioning plants the air used for cooling the room is directly chilled by the refrigerant in the cooling coil of the air handling unit. Due to this heat transfer process is more efficient, since there is no middle agency involved for the heat transfer resulting in higher cooling efficiency.

In case of the chilled water system, the cooling effect from the refrigerant is first transferred to the chilled water, which is then used to chill the air used for cooling the room. There is some loss of the cooling effect when it is being transferred from the refrigerant to the chilled water and from there to the air due to which the chilled water systems have lesser cooling efficiency. The chilled water acts as the secondary medium for cooling the room air in air handling unit.

6) sketch and explain fire escapes routes,means and element of planning high rise building with due consideration for fire safety

In terms of fire safety, the final exits on an escape route in a public building are known as fire exits. They may or may not be located on the usual route of traffic when the premises are operating under normal circumstances. The final exit doors should open easily, immediately and, wherever practicable, in the direction of escape, i.e. outwards into a place of safety outside the building. Sliding or revolving doors must not be used for exits specifically intended as fire exits. The emergency routes and fire exits must be well lit and indicated by appropriate signs, e.g. Fire Exit Keep Clear. In locations that require illumination, emergency lighting of adequate intensity must be provided in case the normal lighting fails, and illuminated signs used. This is because, as noted in the HM Government publication Fire Safety Risk Assessment: Offices and Shops (May 2006): The primary purpose of emergency escape lighting is to illuminate escape routes but it also illuminates other safety equipment.

The Process of Escape

Having considered the factors that will influence escape, and having seen how these can be related to the risk profile and / or occupancy levels of a specific building, it is important to look at the stages in the process of escape and the maximum distances people can be expected to travel.

Escape is generally considered in four distinct Stages as follows

Stage 1 escape from the room or area of fire origin

Stage 2 escape from the compartment of origin via the circulation route to a protected stairway or an adjoining compartment offering refuge

Stage 3 escape from the floor of origin to the ground level

Stage 4 escape at ground level away from the building.

It is important that each floor plan of a building indicates the shortest route(s) to a place of comparative or ultimate safety should an emergency evacuation be triggered, e.g. by the sounding of the fire alarm. The width of final exit doors and the escape routes leading to them will dictate the maximum number of people who can safely occupy that floor or a specific area within it under normal conditions of operation.

buildings are built taller and taller, new fire escape ideas have been gaining popularity. Elevators, though traditionally not used as fire escapes, are now being thought of as a possible evacuation for high-rises and skyscrapers.[5] Other alternate high-rise fire escape solutions include parachutes, external collapsible elevators, slides,[6] and controlled descent systems such as SkySaver.[7]

7) types of fan and filter used in mechanical ventilationCross flow fancrosssflow fans, often referred to as tangential or blower wheel fans, will generate a wide, even flow of air parallel to the unit being cooled, insuring greater efficiencies and lower noise ratios per cfm when compared with axial fans.

Air filter

8) reverberation time and sabines method of achieving the same.

Reverberation, in psychoacoustics and acoustics, is the persistence of sound after a sound is produced.[1] A reverberation, or reverb, is created when a sound or signal is reflected causing a large number of reflections to build up and then decay as the sound is absorbed by the surfaces of objects in the space which could include furniture and people, and airThe time it takes for a signal to drop by 60dB is the reverberation time.

The total absorption in sabins (and hence reverberation time) generally changes depending on frequency (which is defined by the acoustic properties of the space). The equation does not take into account room shape or losses from the sound travelling through the air (important in larger spaces). Most rooms absorb less sound energy in the lower frequency ranges resulting in longer reverb times at lower frequencies.

Sabine concluded that the reverberation time depends upon the reflectivity of sound from various surfaces available inside the hall. If the reflection is coherent, the reverberation time of the hall will be longer; the sound will take more time to die out.

9) hot water supply and building heating system a source of hot water for residences and public and industrial enterprises to satisfy domestic and production needs; also, the complex of equipment and structures that provide it. Hot water supply systems consist of heat sources, water treatment apparatus, water heaters, pipelines to transport the water, and devices to regulate and control the waters temperature.The water provided by hot water supplies in residential and public buildings and in industrial enterprises for their operational and daily needs must be potable and must satisfy the requirements of the All-Union State Standards. The quality of water intended for technical use is determined by the type of production service it will fulfill. Hot water supplies may be either centralized or local (decentralized). In centralized systems, the heat is generated by heat and electric power plants; and the so-called waste heat of industrial enterprises, underground sources, and other sources is also used. The heat is transmitted to consumers through heating system pipelines. The treatment of hot water is carried out at the heat sources themselves and at central heating points or right in the home. In local systems, the source of heat for warming the water is located at the place where the water is used. A centralized hot water supply may be a closed system in which the water is warmed by a heat-transfer medium (water or steam) from heating networks in water heaters that have been installed at central heating points or directly within the home. In hot water supplies built as open systems, the consumer obtains hot water directly from a heating network. This does away with the need to install water heaters in homes or at centralized heating points and lessens the possibility of corrosion in local pipelines. However, the maintenance of a demand level in such systems requires large volumes of water that have undergone preliminary treatment to prevent scaling and corrosion in the pipelines and the heat-transfer equipment. The maximum water temperature in hot water supplies is 75 C and the minimum (at water faucets) is 60 C.To prevent cooling of the water in hot water supply delivery pipelines, a constant circulation is maintained during low-demand periods with the help of so-called circulation pipelines. In baths and showers there are heaters connected to the circulating system; with these the rooms are warmed and the towels are dried.In order to even out the high- and low-demand loads and to cut the costs of heat sources, heat exchangers, heating networks, and water treatment, hot water accumulator tanks are used in centralized systems to store the hot water during low-demand periods, for its distribution during high-demand periods. All new residences and public buildings being constructed in the cities and industrial settlements of the USSR, as a rule, are provided with centralized hot water supplies. This also applies to all industrial enterprises.In a local hot water supply system, the water heaters are installed right at the locations where the hot water will be used (baths, showers, washing machines, production equipment) and are heated by the burning of fuel (gaseous, liquid, or solid) or electric power. These devices usually require considerable expenditures of time and labor for servicing and, as a rule, do not operate continuously.

10) Building Heating systemIntroductionHeatingin buildings may be necessary to: Create comfortable conditions for occupants. To preventcondensation. For activities such as drying and cooking. For industrial processes.In commercial buildings,heatingfor comfort might be provided alongside otherbuilding servicesinheating, ventilation and air conditioning(HVAC) systems.Heat sourcesExamples of fuels and heat sources include: Solid fuel timber, coal, peat,biomass. Liquid oil, liquid petroleum gas (LPG). Gas - natural gas,biogas. Electricity - grid, wind turbines,hydroelectricity,photovoltaics. Water solar thermal, geothermal, ground source, water source. Air source. Heat recovery. Passive solar gain,thermal mass. Internal heat loads - heat generated by people andequipment.Heat generatorsHeat sources and fuels can be used to generate heat by: Boilers. Solid fuel burners. Combined heat and power(CHP) plant. Electrical heaters. Gas heaters. Heat pumps.Heat distributionHeat generators can be local to the demand for heat, or can be centralised and distributed, either within a single building or on a wider basis as part of adistrict heatingnetwork. Heat distribution can be by: Air blown through ducts,plenumsor occupied spaces. Water pumped through pipework. Steam distributed through pipework. Passive air movement. Passive diffusion of heat throughthermal mass.ControlsThe amount of heat delivered to a space can be controlled: Locally by manual or automated thermostats, switches ordampers. Centrally by manual or automated thermostats, switches ordampers. Building management systems.Heatingcontrol systems often require re-evaluation once buildings are completed and occupied. Systems may require fine-tuning as internal heat loads and occupant behaviour do not always conform with design expectations. Occupant training can be helpful to optimise the performance ofheating systems, and occupants can be appreciative of a degree of local control.OptimumtemperaturesThe human thermal environment is not straight forward and cannot be expressed in degrees. Nor can it be satisfactorily defined by acceptabletemperatureranges. It is a personal experience dependent on a great number of criteria and can be different from one person to another within the same space.Environmental factors: Air temperature. Air velocity. Radiant temperature. Relative humidity.Personal factors: Clothing. Metabolic heat. Wellbeing.For more information seethermal comfort.

11) air handling unitAn air handler, or air handling unit (often abbreviated to AHU), is a device used to regulate and circulate air as part of a heating, ventilating, and air-conditioning (HVAC) system.[1] An air handler is usually a large metal box containing a blower, heating or cooling elements, filter racks or chambers, sound attenuators, and dampers.[2] Air handlers usually connect to a ductwork ventilation system that distributes the conditioned air through the building and returns it to the AHU. Sometimes AHUs discharge (supply) and admit (return) air directly to and from the space served without ductwork.

Small air handlers, for local use, are called terminal units, and may only include an air filter, coil, and blower; these simple terminal units are called blower coils or fan coil units. A larger air handler that conditions 100% outside air, and no recirculated air, is known as a makeup air unit (MAU). An air handler designed for outdoor use, typically on roofs, is known as a packaged unit (PU) or rooftop unit (RTU).

11) different types of installation of package unit for air conditioning

An HVAC designer will recommend different types of air conditioning systems for different applications. The most commonly used are described in this article.

The choice of which air conditioner system to use depends upon a number of factors including how large the area is to be cooled, the total heat generated inside the enclosed area, etc. An HVAC designer would consider all the related parameters and suggest the system most suitable for your space.

Window Air ConditionerWindow air conditioner is the most commonly used air conditioner for single rooms. In this air conditioner all the components, namely the compressor, condenser, expansion valve or coil, evaporator and cooling coil are enclosed in a single box. This unit is fitted in a slot made in the wall of the room, or more commonly a window sill.

Split Air ConditionerThe split air conditioner comprises of two parts: the outdoor unit and the indoor unit. The outdoor unit, fitted outside the room, houses components like the compressor, condenser and expansion valve. The indoor unit comprises the evaporator or cooling coil and the cooling fan. For this unit you dont have to make any slot in the wall of the room. Further, present day split units have aesthetic appeal and do not take up as much space as a window unit. A split air conditioner can be used to cool one or two rooms.

Packaged Air ConditionerAn HVAC designer will suggest this type of air conditioner if you want to cool more than two rooms or a larger space at your home or office. There are two possible arrangements with the package unit. In the first one, all the components, namely the compressor, condenser (which can be air cooled or water cooled), expansion valve and evaporator are housed in a single box. The cooled air is thrown by the high capacity blower, and it flows through the ducts laid through various rooms. In the second arrangement, the compressor and condenser are housed in one casing. The compressed gas passes through individual units, comprised of the expansion valve and cooling coil, located in various rooms.

Central Air Conditioning SystemCentral air conditioning is used for cooling big buildings, houses, offices, entire hotels, gyms, movie theaters, factories etc. If the whole building is to be air conditioned, HVAC engineers find that putting individual units in each of the rooms is very expensive making this a better option. 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 units.

12) prevention of noise transfer through a.c.ducts 13) static tank

STATIC WATER TANKS

Static water tanks are very useful sources of water supplies for major fire fighting. They can be provided to supplement the first hydrant system or independently where provision of fire hydrants is not feasible economically or due to various other reasons. Static water system has many advantages over the hydrant system. This system is much more economical, more reliable, less prone to damage or defects and helps to build huge reserve to meet any eventualities. While planning any water supply system for fire fighting in towns, cities and industries, suitable provision of static water tanks shall always be kept in view. For civil defence towns/cities and all type of industrial establishment, at least 50 percent of the total water supply requirements for fire fighting shall always be in the form of static water tanks.

Static water tanks for fire fighting should be underground with water at ground level. They can be of any shape and dimensions, but the depth shall normally not exceed 25 m. For multi-storey buildings terrace tank may be provided.NOTEIn case of deeper tanks, submersible pumps be provided.

For towns/cities and other locations where they are accessible to public, the static tank should be completely covered and provided with suitable manholes for lowering of the suction hoses.

Inside industrial establishments the static water tanks can be of open type having small parapet walls of height not exceeding 50 cm above ground level. Such tanks may, as far as possible, conform to Fig. 1. Where extra

All static water tanks for fire fighting shall normally be located within 100 m of the risk to be protected.

The static water tanks shall be easily approachable by all types of the appliances held at the fire station(s) providing fire cover in the area. All weather approach road of adequate size shall be provided. Provision of suitable number of manholes shall be made available for inspection, repairs and inspection of static tanks, etc.

Cement concrete platforms (hard standings) shall be provided at suitable locations around the static water tanks for prolonged operations by the fire pumps.

Each static water tank should be provided with sump(s) to allow the use of the total quantity of water for fire lighting and also to facilitate maintenance and repair of tanks. The sump(s) may be of the size 1 m 1 m 45 cm (depth). The sumps should be located on the side(s) from where the fire pumps are to come into operation.

U-shaped steel bar steps or any other suitable arrangement shall be provided for men to enter the static water tanks as and when required.

All static water tanks shall be provided with suitable filling arrangements to make up the evaporation losses, refilling after cleaning/repairs and for replenishing water supplies during fire fighting operations. The filling arrangements shall be of the maximum capacity possible and the tanks shall be connected by the biggest size of mains available in their vicinity at the rate of not less than 1 000 l/minute.

Suitable indicating plates shall be fixed to the nearest wall or a suitable posts erected for the purpose near each static water tank. The indicating plates can be made of vitreous enamelled mild steel, cast iron, aluminium alloy or plastic. The plates shall be yellow in colour with letter SWT and the capacity in litres marked in black.

14)sprinklers

A fire sprinkler or sprinkler head is the component of a fire sprinkler system that discharges water when the effects of a fire have been detected, such as when a predetermined temperature has been exceeded. Fire sprinklers are extensively used worldwide, with over 40 million sprinkler heads fitted each year. In buildings protected by fire sprinklers, over 99% of fires were controlled by fire sprinklers alone.[1][2][3]Each closed-head sprinkler is held closed by either a heat-sensitive glass bulb (see below) or a two-part metal link held together with fusible alloy such as Wood's metal[10] and other alloys with similar compositions.[11] The glass bulb or link applies pressure to a pipe cap which acts as a plug which prevents water from flowing until the ambient temperature around the sprinkler reaches the design activation temperature of the individual sprinkler. Because each sprinkler activates independently when the predetermined heat level is reached, the number of sprinklers that operate is limited to only those near the fire, thereby maximizing the available water pressure over the point of fire origin.

The bulb breaks as a result of the thermal expansion of the liquid inside the bulb.[12] The time it takes before a bulb breaks is dependent on the temperature. Below the design temperature, it does not break, and above the design temperature it breaks, taking less time to break as temperature increases above the design threshold.

15)fire hydrants

A fire hydrant is an active fire protection measure, and a connection point by which firefighters can tap into a water supply.

The user attaches a hose to the fire hydrant, then opens a valve on the hydrant to provide a powerful flow of water, on the order of 350 kPa (50 lbf/in) (this pressure varies according to region and depends on various factors including the size and location of the attached water main). This user can attach this hose to a fire engine, which can use a powerful pump to boost the water pressure and possibly split it into multiple streams. One may connect the hose with a threaded connection, instantaneous "quick connector". A user should take care not to open or close a fire hydrant too quickly, as this can create a water hammer which can damage nearby pipes and equipment. The water inside a charged hoseline causes it to be very heavy and high water pressure causes it to be stiff and unable to make a tight turn while pressurized. When a fire hydrant is unobstructed, this is not a problem, as there is enough room to adequately position the hose.

When a firefighter is operating a hydrant, he or she typically wears appropriate personal protective equipment, such as gloves and a helmet with face shield worn. High-pressure water coursing through a potentially aging and corroding hydrant could cause a failure, injuring the firefighter operating the hydrant or bystanders.

In most jurisdictions it is illegal to park a car within a certain distance of a fire hydrant. the distances are commonly 3 to 5 m or 10 to 15 ft, often indicated by yellow or red paint on the curb. The rationale behind these laws is that hydrants need to be visible and accessible in an emergency.

16)central water heating system

A central heating system provides warmth to the whole interior of a building (or portion of a building) from one point to multiple rooms. When combined with other systems in order to control the building climate, the whole system may be an HVAC (heating, ventilation and air conditioning) system.

The term central heating covers hydronic heating systems with a central boiler or furnace either inside the building being heated or in the immediate vicinity.The term central heating covers hydronic heating systems with a central boiler or furnace either inside the building being heated or in the immediate vicinity.Heat is generated in the boiler. Pipes carry the heated water to the buildings heat sources (radiators) and return the cooled water to the boiler again.Originally, many central heating systems were designed to be self-circulating. Now a circulator is always used to pump heat through the system.A central heating system is a closed system with either an expansion tank or open expansion vessel. A buffer tank can also be installed in the system.A wide range of fuel types are used in central heating. Coal, coke, wood, oil, gas, wood chips and wood pellets have all proven adequate fuel sources in central heating boilers.

17) radiator

Radiators are heat exchangers used to transfer thermal energy from one medium to another for the purpose of cooling and heating. The majority of radiators are constructed to function in automobiles, buildings, and electronics. The radiator is always a source of heat to its environment, although this may be for either the purpose of heating this environment, or for cooling the fluid or coolant supplied to it, as for engine cooling. Despite the name, radiators generally transfer the bulk of their heat via convection, not by thermal radiation, though the term "convector" is used more narrowly; see radiation and convection, below.

18)fire resistant door

A fire door is a door with a fire-resistance rating (sometimes referred to as a fire protection rating for closures) used as part of a passive fire protection system to reduce the spread of fire or smoke between compartments and to enable safe egress from a building or structure or ship. In North American building codes, it, along with fire dampers, is often referred to as a closure, which can be derated compared against the fire separation that contains it, provided that this barrier is not a firewall or an occupancy separation.Wire mesh glass - usually Georgian wiredLiquid sodium silicate fills between two window panesCeramic glassesBorosilicate glass1. No open holes or breaks exist in surfaces of either the door or frame.2. Glazing, vision light frames & glazing beads are intact and securely fastened in place, if so equipped.3. The door, frame, hinges, hardware, and noncombustible threshold are secured, aligned, and in working order with no visible signs of damage.4. No parts are missing or broken.5. Door clearances at the door edge of the door frame (Wood Door), on the pull side of the door, do not exceed clearances listed in 4.8.4 (the clearance under the bottom of the door shall be a maximum of 3/4") and 6.3.1 (top & edges 1/8") Metal door (top & edges up to 3/16")6. The self-closing device is operational; that is, the active door completely closes when operated from the full open position.7. If a coordinator is installed, the inactive leaf closes before the active leaf.8. Latching hardware operates and secure the door when it is in the closed position.9. Auxiliary hardware items that interfere or prohibit operation are not installed on the door or frame.10. No field modifications to the door assembly have been performed that void the label.11. Gasketing and edge seals, where required, are inspected to verify their presence and integrity.19) Fire dampers

Fire dampers are passive fire protection products used in heating, ventilation, and air conditioning (HVAC) ducts to prevent the spread of fire inside the ductwork through fire-resistance rated walls and floors. Fire/smoke dampers are similar to fire dampers in fire resistance rating, and also prevent the spread of smoke inside the ducts. When a rise in temperature occurs, the fire damper closes, usually activated by a thermal element which melts at temperatures higher than ambient but low enough to indicate the presence of a fire, allowing springs to close the damper blades. Fire dampers can also close following receipt of an electrical signal from a fire alarm system utilising detectors remote from the damper, indicating the sensing of heat or smoke in the building occupied spaces or in the HVAC duct system.

20)cooling tower

A cooling tower is a heat rejection device which rejects waste heat to the atmosphere through the cooling of a water stream to a lower temperature. Cooling towers may either use the evaporation of water to remove process heat and cool the working fluid to near the wet-bulb air temperature or, in the case of closed circuit dry cooling towers, rely solely on air to cool the working fluid to near the dry-bulb air temperature.

Cooling towers vary in size from small roof-top units to very large hyperboloid structures (as in the adjacent image) that can be up to 200 metres (660 ft) tall and 100 metres (330 ft) in diameter, or rectangular structures that can be over 40 metres (130 ft) tall and 80 metres (260 ft) long. The hyperboloid cooling towers are often associated with nuclear power plants,[1] although they are also used to some extent in some large chemical and other industrial plants. Although these large towers are very prominent, the vast majority of cooling towers are much smaller, including many units installed on or near buildings to discharge heat from air conditioning.

21) Prevention of echos

Well designed Auditoriums will consist of non-parallel surfaces that will serve to break up standing soundwaves, scattering the acoustics and preventing "dead" spots in the room. If your room is more gymnasium shaped, there will be more repetition in the path of the reflecting sounds. This will increase the potential for "live" or "dead" spots, and therefore increase your need for diffusion panels. Remember that absorption panels reduce background noise, while diffusion panels are designed to scatter sound reflections into multiple directions for greater acoustic balance in the room

For fan shaped auditoriums with inclined floors, use a ratio of 10:1 when determining quantities of diffusion panels over absorption panels.

Thicker material will collapse more low bass reverberation in the room. Go with 2" thick Fabric Panels over the 1" thickness. Our goal is to absorb enough background noise in the room to produce excellent speech clarity, but leave enough reverb in the room to blend the musical tones together.

Large auditoriums need sound absorption materials to reduce reverberation (echo) within the room. Sound absorption materials are critical to the design of auditoriums and theaters as built or as a retrofit application. Auditoriums and theaters often have hard reflective walls and floors requiring sound reduction. Acoustical wall panels, curtains and baffles reduce ambient noise levels.

When building a custom home theater room, you have two different acoustic problems to deal with. One is reducing sound transmission levels from your home theater room to adjoining rooms, basically allowing the home theater to be enjoyed at higher volume levels without disturbing neighbors or houseguests in other rooms. You can add soundproofing to your home theater room by using sound barriers and isolation clips underneath the drywall on the walls and ceilings. The other area to be concerned with when building your custom home theater is improving the sound quality within the home theater room itself, generally this involves the use of sound absorption products. When building a custom home theater room, you must keep in mind the interior finish of the room. wrapped wall panels , which are designed to be acoustically effective and aesthically pleasing. These acoustical wall panels add a plush feel to your home theater interior.

22)sound focus

Any time the surfaces of a room focus the sound which is reflected from them, they create spots of high intensity and other spots with low intensity. This is generally undesirable in an auditorium since you want a uniform, evenly dispersed sound to all listeners.Even large flat reflective surfaces are to be avoided because of the prominant reflection which will be produced. Parallel flat walls can produce a pattern of reflections known as a "flutter echo" as the sound waves travel back and forth between the surfaces. Such flutter echoes are often encountered in high school gymnasiums where there are parallel side walls and also a reflective floor and ceiling.

Even dispersion is such an important contributer to good acoustics that it is sometimes desirable to use anti-focusing surfaces in a music making area. Older architecture often had columns, decorative sculpture and woodwork, and other dispersing surfaces. In modern architecture with its flat expanses, it is necessary to design in some anti-focusing properties.

23)Sound shadow

A phenomenon caused by the ABSORPTION or obstruction of a SOUND WAVE by an object in its path. The effect produced is perceived as a reduction in LOUDNESS depending on the observer's position with respect to the sound source and obstructing object and is greatest when the three are aligned.

High frequencies are more easily absorbed than lower ones, and are less susceptible to DIFFRACTION, that is, they move less easily around objects because of their short WAVELENGTHs. Therefore, the ATTENUATION of high frequencies is noted in a sound shadow. As well, more reflected sound from the environment is likely to be received than direct sound. See: SOUND PROPAGATION, section 2.

Since the head will absorb high frequencies more easily than low ones, it will create a sound shadow for the ear farthest away from the sound source, and therefore the phenomenon plays a role in sound localization. The effect, however, seems less important than time differences for BINAURAL HEARING except in the upper frequency region (see PINNA). Blind people use the sound shadow effect for orientation, as well as reflected sound and other cues. See: ECHOLOCATION.24)calorifier for hot water supply

A Calorifier is an industry term for a storage vessel that has the capacity to generate heat within a mass of stored water.

How does a Calorifier work?

Generation of heat is commonly provided by an indirect heat source via a heat transfer coil or heat tube battery. Historically, Calorifiers have tended to be designed around the capacity of daily water demand, with a low heat input coil that would re-generate the hot water supply during non- peak usage periods. However, recent manufacturing techniques and material quality mean the coil output is able to recover quickly to re-generate much larger quantities of hot water. Heat exchange takes place at the primary coil and is usually supplied via a primary hot water flow through a controlling zone valve from a main central heating boiler, dedicated hot water boiler, or in some cases a renewable energy sourceCalorifierscloseWhere can Calorifiers be used?

Calorifiers may be installed onto an open vented system, with cold water supplied from a storage tank which provides the head pressure for the hot water system. Or, more commonly in commercial applications, an unvented system with cold water supplied directly from mains pressure. And in some cases through a pressure booster set. Many Calorifiers are now available with the option of an additional heat output coil that is heated from a renewable energy source such as solar thermal

25)fire rating materialsRock woolGypsum boardsAsbestos cementPerlite boardsProplex SheetsCalcium silicate boardsTreated lumber plywoodTreated vegetable fiber (e.g. Cotton, Jute, Kenaf, Hemp, Flax, etc..)Fire-retardant treated woodBrickConcreteCement renderIntumescent paintGlassGlass wool

26) ac ducts and dampers

Ducts are used in heating, ventilation, and air conditioning (HVAC) to deliver and remove air. The needed airflows include, for example, supply air, return air, and exhaust air.[1]Ducts commonly also deliver ventilation air as part of the supply air. As such, air ducts are one method of ensuring acceptable indoor air quality as well as thermal comfort.

A duct system is also called ductwork. Planning (laying out), sizing, optimizing, detailing, and finding the pressure losses through a duct system is called duct design.[2]dampers

A damper is a valve or plate that stops or regulates the flow of air inside a duct, chimney, VAV box, air handler, or other air handling equipment. A damper may be used to cut off central air conditioning (heating or cooling) to an unused room, or to regulate it for room-by-room temperature and climate control. Its operation can be manual or automatic. Manual dampers are turned by a handle on the outside of a duct. Automatic dampers are used to regulate airflow constantly and are operated by electric or pneumatic motors, in turn controlled by a thermostat or building automation system. Automatic or motorized dampers may also be controlled by a solenoid, and the degree of air-flow calibrated, perhaps according to signals from the thermostat going to the actuator of the damper in order to modulate the flow of air-conditioned air in order to effect climate control.[1]

In a chimney flue, a damper closes off the flue to keep the weather (and birds and other animals) out and warm or cool air in. This is usually done in the summer, but also sometimes in the winter between uses. In some cases, the damper may also be partly closed to help control the rate of combustion. The damper may be accessible only by reaching up into the fireplace by hand or with a woodpoker, or sometimes by a lever or knob that sticks down or out. On a wood-burning stove or similar device, it is usually a handle on the vent duct as in an air conditioning system. Forgetting to open a damper before beginning a fire can cause serious smoke damage to the interior of a home, if not a house fire.

28)Dead spots and live spots in auditorium

Poorly designed auditoriums can have dead spots. Dead spots are places where destructive interference occurs from the interaction of two or more sound waves. For example, a soloist on stage sends sound waves into the audience. Some of the waves hit the walls of the auditorium, while other waves travel directly to the listeners. In some situations, a direct wave can destructively interfere with a reflected wave so they cancel each other out at that particular location. As a result, the listeners seated in those particular seats would hear nothing from that soloist. Someone sitting a few seats over from the dead spot, however, might not experience the destructive interference and would hear the soloist just fine. (Refer to the chapter on Sound for handy answers dealing with acoustical engineering

29)fire alarm system

A fire alarm system is number of devices working together to detect and alert people through visual and audio appliances when smoke/fire is present. These alarms may be activated from smoke detectors, and heat detectors. They may also be activated via Manual fire alarm activation devices such as manual call points or pull stations.

Fire alarm control panel (FACP) AKA fire alarm control unit (FACU); This component, the hub of the system, monitors inputs and system integrity, controls outputs and relays information.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 constituents. "Dedicated branch circuits" should not be confused with "Individual branch circuits" which supply energy to a single appliance.Secondary (backup) power supplies: This component, commonly consisting of sealed lead-acid storage batteries or other emergency sources including generators, is used to supply energy in the event of a primary power failure.Initiating devices: This component acts as an input to the fire alarm control unit and are either manually or automatically activated. Examples would be devices pull stations, heat detectors, or smoke detectors. Heat and smoke detectors have different categories of both kinds. Some categories are beam, photoelectrical, aspiration, and duct.

Notification appliances: This component uses energy supplied from the fire alarm system or other stored energy source, to inform the proximate persons of the need to take action, usually to evacuate. This is done by means of a flashing light, strobe light, electromechanical horn, "beeper horn", chime, bell, speaker, or a combination of these devices. The System Sensor Spectralert Advance Horn makes a beeping sound and electromechanical sound together. Strobes are either made of a xenon tube (most common), or now LED lights.Building safety interfaces: This interface allows the fire alarm system to control aspects of the built environment and to prepare the building for fire, and to control the spread of smoke fumes and fire by influencing air movement, lighting, process control, human transport and exit.

30) smoke detector

A smoke detector is a device that senses smoke, typically as an indicator of fire. Commercial and residential security devices issue a signal to a fire alarm control panel as part of a fire alarm system, while household detectors, known as smoke alarms, generally issue a local audible or visual alarm from the detector itself.

Smoke detectors are typically housed in a disk-shaped plastic enclosure about 150 millimetres (6 in) in diameter and 25 millimetres (1 in) thick, but the shape can vary by manufacturer or product line. Most smoke detectors work either by optical detection (photoelectric) or by physical process (ionization), while others use both detection methods to increase sensitivity to smoke. Sensitive alarms can be used to detect, and thus deter, smoking in areas where it is banned. Smoke detectors in large commercial, industrial, and residential buildings are usually powered by a central fire alarm system, which is powered by the building power with a battery backup. However, in many single-family detached and smaller multiple family housings, a smoke alarm is often powered only by a single disposable battery.

31)open window units in acoustics

a unit of the absorption of the energy of a diffuse sound field for a surface. A sabin is the absorption by 1 square foot of a surface that reflects none of the energy incident on itthat is, of a surface whose absorption coefficient is unity. The unit was named after the American acoustics specialist W. Sabine (18681919).A simple example of a surface that reflects no sound is provided by an open window. If boundary effects are neglected, all the sound energy incident on the surface passes through it. For this reason, the sabin is sometimes called the open window unit, or OW unit. Other names used for the sabin are absorption unit and square-foot unit of absorption.The absorption of a surface in sabins is determined by taking the sum of the products of the areas, in square feet, of homogeneous sections of the surface and the absorption coefficients of the sections.The sabin is used in American and British works on architectural acoustics. In the USSR, the metric sabin is used. It represents the absorption by an open-window surface that is 1 square meter in area.

32)advantage and disadvantage various shape in design of a auditorium

33)cause and cure of echo

34) wind catcher

A windcatcher is a traditional Persian architectural element to create natural ventilation in buildings.[3] Windcatchers come in various designs: uni-directional, bi-directional, and multi-directional. Windcatchers remain present in many countries and can be found in traditional Persian-influenced architecture throughout the Middle East, including in the small Arab states of the Persian Gulf (mostly Bahrain and Dubai[4]), Pakistan and Afghanistan.[5]

Windcatchers tend to have one, four, or eight openings. In the city of Yazd, all windcatchers are four- or eight-sided. The construction of a windcatcher depends on the direction of airflow at that specific location: if the wind tends to blow from only one side, it is built with only one downwind opening. This is the style most commonly seen in Meybod, 50 kilometers from Yazd: the windcatchers are short and have a single opening.

To keep buildings free of dust and sand blown in from the desert, windcatchers were built facing away from the wind

The windcatcher approach has recently been utilized in Western architecture, such as in the visitor center at Zion National Park, Utah,[12] where it functions without the addition of mechanical devices in order to regulate temperature.[13]

Using aluminum for the windcatcher provides a more efficient capturing system, allowing for wind capture from multiple directions. The Kensington Oval cricket ground in Barbados and the Saint-tienne Mtropoles Zenith both use this method

35) cross ventelation

Ventilation is necessary in buildings to remove stale air and replace it with fresh air:Helping to moderate internal temperatures.Reducing the accumulation of moisture, odours and other gases that can build up during occupied periods.Creating air movement which improves the comfort of occupants.Very broadly, ventilation in buildings can be classified as natural or mechanical.Mechanical (or forced) ventilation tends to be driven by fans.Natural ventilation is driven by natural pressure differences from one part of the building to another.Natural ventilation can be wind-driven (or wind-induced), or it can be buoyancy-driven stack ventilation. For more information about buoyancy-driven stack ventilation, see Stack effect.Cross ventilation occurs where there are pressure differences between one side of a building and the other. Typically this is a wind-driven effect in which air is drawn into the building on the high pressure windward side and is drawn out of the building on the low pressure leeward side. Wind can also drive single-sided ventilation and vertical ventilation.Whereas cross ventilation is generally more straight-forward to provide than stack ventilation, it has the disadvantage that it tends to be least effective on hot, still days, when it is needed most. In addition, it is generally only suitable for narrow buildings.If there are windows on both sides, then cross ventilation might be suitable for buildings where the width is up to five times the floor to ceiling height. Where there are only openings on one side, wind-driven ventilation might be suitable for buildings where the width is up to 2.5 times the floor to ceiling height.Beyond this, providing sufficient fresh air creates draughts close to openings, and additional design elements such as internal courtyards are necessary, or the inclusion of elements such as atrium that combine cross ventilation and stack effects, or mechanically assisted ventilation.Cross ventilation is most suited for buildings that are:Narrow.On exposed sites.Perpendicular to the prevailing wind.Free from internal barriers to air flow.Provided with a regular distribution of openings.It is less suitable where: The building is too deep to ventilate from the perimeter.Local air quality is poor, for example if a building is next to a busy road.Local noise levels mean that windows cannot be opened.The local urban structure is very dense and shelters the building from the wind.Privacy or security requirements prevent windows being opened.Internal partitions block air paths.Some of these issues can be avoided or mitigated by careful siting and design of buildings. For example, louvres can be used where ventilation is required, but a window is not, and ducts or openings can be provided in internal partitions, although these will only be effective if there is sufficient open area, and there may be problems with acoustic separation.Cross ventilation can be problematic during the winter when windows may be closed, particularly in modern buildings which tend to be highly sealed. Trickle ventilation, or crack settings on windows can be provided to ensure there is adequate background ventilation. Trickle ventilators can be self-balancing, with the size of the open area depending on the air pressure difference across it.In straight-forward buildings, cross ventilation can often be designed by following rules of thumb for the openable area required for a given floor area, depending on the nature of the space and occupancy. The situation becomes more complicated when cross ventilation is combined with the stack effect or mechanical systems, and thermal mass and solar gain are taken into consideration. Modelling this behaviour can become extremely complicated, sometimes requiring the use of local weather data, software such as computational fluid dynamics (CFD) programs and even wind tunnel testing.Ventilation in buildings is regulated by Part F of the building regulations.

37) Stack effectStack effect is the movement of air into and out of buildings, chimneys, flue gas stacks, or other containers, resulting from air buoyancy. Buoyancy occurs due to a difference in indoor-to-outdoor air density resulting from temperature and moisture differences. The result is either a positive or negative buoyancy force. The greater the thermal difference and the height of the structure, the greater the buoyancy force, and thus the stack effect. The stack effect is also referred to as the "chimney effect", and it helps drive natural ventilation, infiltration, and fires (see Kaprun disaster and King's Cross fire).

Since buildings are not totally sealed (at the very minimum, there is always a ground level entrance), the stack effect will cause air infiltration. During the heating season, the warmer indoor air rises up through the building and escapes at the top either through open windows, ventilation openings, or unintentional holes in ceilings, like ceiling fans and recessed lights. The rising warm air reduces the pressure in the base of the building, drawing cold air in through either open doors, windows, or other openings and leakage. During the cooling season, the stack effect is reversed, but is typically weaker due to lower temperature differences.

In a modern high-rise building with a well-sealed envelope, the stack effect can create significant pressure differences that must be given design consideration and may need to be addressed with mechanical ventilation. Stairwells, shafts, elevators, and the like, tend to contribute to the stack effect, whereas interior partitions, floors, and fire separations can mitigate it. Especially in case of fire, the stack effect needs to be controlled to prevent the spread of smoke and fire, and to maintain tenable conditions for victims and firefighters.[1]

38) wind pressure test

Air pressure testing is a method of measuring and quantifying the air leakage of a building. The test consists of putting a fan contained in a temporary screen into an outside door rebate and pressurising or depressurising the building whilst recording the air leakage rates. The external air pressure, wind speed and temperature are measured at the same time, since they have a bearing on the results of the test. Part 1LA of the Building Regulations 2006 makes it a legal requirement that new domestic dwellings pass a mandatory air tightness test before being occupied.What is air leakage in buildings?Air leakage (also known as air permeability or air infiltration) is the air lost from a dwelling through uncontrolled means such as cracks and gaps in the building envelope. Any ventilation system installed in a building is seen as a source of controlled air flow and is therefore not considered as air leakage. At a very basic level, air leakage may be seen as unwanted draughts.Why do I need to test the air tightness of a building?Air pressure testing of a proportion of all new domestic housing is a legal requirement in accordance with the guidance given in Approved Document Part L1A - Conservation of Fuel and Power in New Dwellings of the Building Regulations. Testing the air tightness of existing dwellings can highlight problematic areas which can then be treated cost-effectively to improve the energy efficiency of the dwelling as a whole.

39) dry riserA dry riser is a main vertical pipe intended to distribute water to multiple levels of a building or structure as a component of the fire suppression systems.

The pipe is maintained empty of water. The dry riser is the opposite of a "wet riser" or "wet standpipe" system where the pipes are kept full of water for manual or automatic fire fighting operations. Dry risers have to allow access to a fire engine within 18 m of the dry riser inlet box. Dry risers in occupied buildings have to be within a fire resistant shaft, usually one of a building's fire escape staircase enclosures.

Depending on regional nomenclature, the term "dry riser" may refer to a standpipe, intended to provide water to fire hose connections, or a vertical main pipe in an automatic dry pipe fire sprinkler system. A dry standpipe comprises a fire department connection, e.g. Storz, which is an external access point at ground level through which water can be pumped from the fire department's fire engine pump to firefighters' fire hose attachments on each floor, whereas a dry pipe fire sprinkler system is a network of pipes connected to fixed sprinklers inside a building, which are full of air until one of the sprinklers is triggered.