Building Construction Multiple Choice Questions & Answers (MCQs) on “Systems and Essentials of Air Conditioning System”.
1. Room air conditioners and packaged units are examples of _________
a) Direct expansion systems
b) Indirect expansion systems
c) Chilled water systems
d) Indirect contraction systems
Answer: a
Clarification: Air conditioning systems are classified into two categories. These are direct expansion systems and chilled water systems. Room air conditioners and packaged units are examples of direct expansion systems.
2. Which of the following is not a component of packaged air conditioners?
a) Compressor
b) Condenser
c) Chiller
d) Evaporator
Answer: c
Clarification: Packaged air conditioners consist of a compressor, condenser, evaporator and a fan. Unlike packaged air conditioners, chilled water system consists of an additional item called the chiller.
3. In a chilled water system, the refrigerant is used to cool the air directly while in the direct expansion system, a secondary medium like water is used to cool the air.
a) True
b) False
Answer: b
Clarification: In the direct expansion system, the refrigerant is used to cool the air directly while in the chilled water system, a secondary medium like water is used to cool the air. In the chilled water system, the refrigerant first cools the water and then the water cools the air.
4. In which component of the chilled water system, the return air and the fresh air mixture is filtered?
a) Fan coil unit
b) Ducting grill
c) Compressor
d) Evaporator
Answer: a
Clarification: In the chilled water system, the return air and the fresh air mixture is filtered in the fan coil unit. Here, in addition to filtration, the mixture is cooled and dehumidified. After this, it is distributed to the conditioned space through ducting and grills.
5. Which of the following qualities is not possessed by the filters in the air conditioning system?
a) They should be capable of removing dust particles from the incoming air
b) They should afford easy cleaning
c) They should offer low frictional resistance to the airflow
d) They should offer high frictional resistance to the airflow
Answer: d
Clarification: The filters in the air conditioning system should be capable of removing dust particles from the incoming air. They should afford easy cleaning and should offer low frictional resistance to the airflow.
6. Viscous type filters are made of screens of spilt wire and coated with non-drying viscous oil in order to catch and remove the dust particles from the incoming air.
a) True
b) False
Answer: a
Clarification: Viscous type filters are made of screens of spilt wire and coated with non-drying viscous oil in order to catch and remove the dust particles from the incoming air. They can be of two types – unit type or automatic type.
7. Which of the following types of filters used in the air conditioning system is made of cloth that is discarded on getting dirty?
a) Viscous type filters
b) Dry filter
c) Spray washers
d) Electric precipitators
Answer: b
Clarification: Filters used in air conditioning system are of various types. There are viscous type filters, dry filters, spray washers and electric precipitators. A dry filter is made of cloth such as flannel, that is discarded on getting dirty.
8. Which of the following statements about electric precipitators is false?
a) They are used to remove dust by providing a strong electric field
b) Their initial installation cost is high
c) Their operational cost is low
d) Dust particles get attached to the positive electrode
Answer: d
Clarification: Electric precipitators are used to remove dust by providing a strong electric field. In an electric precipitator, the dust particles get attached to the negative electrode. Their initial installation cost is high but their operational cost is low.
9. The process of extraction of the certain required amount of water from air is known as ___________
a) Heating
b) Cooling
c) Humidification
d) Dehumidification
Answer: d
Clarification: The process of extraction of a certain required amount of water from air is known as dehumidification. This can be achieved by condensation or desiccation. Humidification is the addition of water to air.
10. Which of the following is capable of absorbing excess moisture from the air?
a) Silica gel
b) Charcoal
c) Salts of calcium or ammonia
d) Activated alumina
Answer: c
Clarification: Absorbents like salts of calcium or ammonia are capable of absorbing excess moisture from the air. However, the adsorbents like silica gel and activated alumina allow moisture to stay only at the surface.