03. ACR-104 UNIT 21 PRACTICE TEST

The difference in temperature between the boiling refrigerant temperature and the evaporator outlet temperature is known as ___________.

• temperature difference

• delta T

• suction line superheat

• evaporator superheat

Low temperature food storage applications typically have a temperature range of ________.

• 0 to -32°F

• 0 to -20° F

• -20 to -32°F

• 0 to 32°F

When the evaporator removes heat from the air and lowers the temperature of the air, _________.

• sensible heat is removed from the air

• latent heat is added to the air

• moisture is added to the air

• refrigerant vapor condenses to liquid

When moisture is removed from the air, latent heat is removed.

• True

• False

Natural-convection evaporators use a blower to force or induce air over the coil to improve the efficiency of the heat exchange.

• True

• False

When a refrigerated space has been allowed to warm up considerably, the system must ________.

• go through a hot pulldown

• be defrosted at regular intervals

• turned off and the product being cooled moved to another cooler

• be overcharged to remove the excess heat

Flooding the compressor crankcase with liquid refrigerant can cause ________.

• excessive superheat

• oil foaming

• a starved evaporator

• moisture to accumulate in the compressor oil

Low-temperature evaporator coils __________.

• have more fins per inch than medium temperature evaporator coils

• operate the same as medium temperature evaporator coils

• have fewer fins per inch than medium temperature evaporator coils

• require more oil circulation that medium temperature evaporator coils

Two common methods for defrosting a low temperature evaporator are __________.

• off-cycle and hot gas

• off-cycle and electric heat

• reverse cycle and hot gas

• hot gas and electric heat

When liquid refrigerant floods the compressor crankcase, the oil level in the crankcase can drop causing _______.

• bearing washout

• excessive superheat

• condenser flooding

• valve damage