This set of Building Materials Questions and Answers for Experienced people focuses on “Variations in Ventilation System with Climate”.
1. Combination system consist of supply system and __________ system.
b) Air conditioning
Explanation: The combination of exhaust and supply system gives better results. The exhaust fans and input fans are installed and suitable places in the outside walls so as to cause a current of fresh air from outside to inside of the room.
2. In _______________ process, the fresh air is forced in the room and the vitiated air is allowed to leave the room by itself or is extracted by outlet fans.
b) Air conditioning
Explanation: The Plenum process may be employed for the downward ventilation or upward ventilation. In the former case, the incoming air is allowed to enter at the ceiling height and while mixing with the vitiated air during its download journey, it is taken out through outlets situated at floor level.
3. The term __________ is used to indicate the science of controlling air with respect to humidity, temperature, movement of air, bacteria content, etc.
a) Air conditioning
Explanation: Air conditioning is the most effective system of artificial ventilation and as it involves many other aspects. It is so as to make the air to suit the physiological requirements of the human body or to the needs of industrial processes.
4. ________________ are made of mats or screens of split wire or glass wool or such other material and coated with non drying viscous oil.
a) Dry filters
b) Water sprays
c) Electric precipitator
d) Viscous filters
Explanation: The viscous filters maybe of unit type or automatic type. In the former type, the Mats are replaced when they become dirty or they are washed and recoiled. In the latter type, an endless chain moving over the mats is provided.
5. __________________ are used to collect the valuable chemical or mineral dusts.
a) Dry filters
b) Viscous filters
c) Water filters
d) Electric precipitator
Explanation: The initial cost of electric precipitators is high, but the operation cost is low. A strong electric field is developed and dust particles when subjected to this electric field are attracted towards negative electrode. The sufficient quantity of dust particles deposited on negative electrode is removed at intervals.
6. In winter, it becomes necessary to supplied slightly _________ air to the inside of the building
Explanation: During winter, heating of air will also compensate heat loss from the room. The preheating of incoming air may be carried out by warm air furnaces or by coils around which hot water or steam is circulating. The incoming air is allowed to pass over warm air furnaces before it enters the room.
7. In summer, it is necessary to supply ___________ air inside the room before it enters the room.
Explanation: The cooling can be carried out by mechanical refrigeration or water spray or by cold water. In mechanical refrigeration system, volatile refrigerant is compressed, cooled and allowed to expand and then, it is passed through coils. Such coils absorb heat from the incoming air.
8. _____________ is the process by which the required amount of moisture is added in the air.
Explanation: For humidification, the income air is allowed to pass through pans of water or wetted cloth strips. For humidifying huge quantity of air, the spray humidifiers may be employed.
9. ________________ is the process by which the required amount of moisture is taken out from the air.
Explanation: The Dehumidification may be carried out by first bringing down the temperature of air below the Dew Point, then condensing out the required quantity of moisture from it and then reheating the air with dry heat upto the desired temperature.
10. The _________ are the substances which allow moisture to stay on their surfaces.
Explanation: The commonly used Adsorbents are Silica Gel and activated Alumina. When sufficient amount of moisture is collected on absorbents, they can be reactivated by heating.
11. In Summer, the outside air is hot and hence the process of air conditioning involves filtering, dehumidification and _________
b) Pre heating
Explanation: The temperature of inside air will be lower than that of outside air and it will be economical to recirculate a part of the room air. The summer air conditioning consists of filters which Dehumidified the air and then it is followed by reheating.
12. In Winter, the outside air is cool and hence, the process of air conditioning involves filtering, preheating and _____________
Explanation: The temperature of inside air will be higher than that of outside air and it will be economical to recirculate a part of room air. In winter air conditioning the circulated air is passed through filters and then it is preheated and humidified.
13. ________________ are made of sheet metal of suitable size and shape to convey the conditioned air.
Explanation: The ducts are to be carefully design with regard to pressure, velocity and volume of air. The ducts should be so shaped than located that even distribution of conditioned air takes place in a room.
14. The location of _________ depends on various factors such as structural features, composition of openings, height of room, etc.
Explanation: The outlets maybe situated in ceiling or Wall. The Ceiling outlets maybe in the form of diffuser, pans or perforated panels. The air is discharge at the ceiling level.
15. The ____________ of suitable type may be used to distribute air inside the room.
Explanation: The selection of air conditioning pumps should be made while keeping in view its efficiency, capacity, available motive power, permissible noise level, etc. Whereas, the wall outlets maybe take various form such as diffuser, grills, etc.
Sanfoundry Global Education & Learning Series – Construction and Building Materials.
To practice all areas of Building Materials for Experienced people, here is complete set of 1000+ Multiple Choice Questions and Answers.