Quiz on Forced Draft Evaporators and Compressors

What material is commonly used to make the fins of forced draft evaporators?

• Copper

• Stainless steel

• Aluminium

• Bronze

What type of compressor uses a spring-loaded blade?

• Reciprocating

• Rotary

• Scroll

• Twin screw

What type of expansion device must be used if a DX evaporator is fitted with a distributor?

• Low side float valve

• High side float valve

• Internally equalised

• Externally equalised

When should a suction line filter drier be fitted to a semi-hermetic system?

• When charging a newly installed system

• After a compressor motor burn-out

• Recovering the refrigerant charge

• If recommissioning an old system

What is the purpose of a suction line accumulator?

• To hold liquid refrigerant during the pump-down cycle.

• To filter the refrigerant of moisture and impurities.

• To prevent liquid flood back in reverse cycle systems.

• To store oil and return it to the compressor sump.

What is the principle reason for fitting a sight glass?

• To check for a full liquid line before expansion.

• To ensure the correct flash gas level is achieved.

• To access the correct oil return to the compressor.

• To remove any moisture from the refrigerant.

What defrost method requires a pump-down cycle?

• Saturated gas.

• Reverse cycle.

• Hot gas.

• Electric.

What would be the ideal saturated temperature for a refrigerant in an air-cooled condenser in a 28°C ambient?

• 55°C.

• 44°C.

• 32°C.

• 28°C.

What is the ideal evaporating temperature for an industrial blast freezer?

• -40°C.

• -30°C.

• -20°C.

• -10°C.

What room temperature is typically required for a butcher's shop cold store?

• 10°C

• 2°C

• -10°C

• -30°C