HVAC-101 Mid Term

Tech A says that heat is removed from the passenger compartment by the heater core. Tech B says that heat in the cab is removed through by the refrigerant and is released to the outside air at the condenser. Who is correct? 

• Tech A

• Tech B

• Both A and B

• Neither A nor B

When the air-conditioning compressor clutch is ________, the pulley attached via a belt to the crankshaft can spin freely. 

• Engaged

• Disengaged

• Connected

• Energized

The purpose of the evaporator in the A/C system is to do all the following EXCEPT: 

• transform liquid refrigerant to a gas. 

• remove the heat from the inside of the cabin

• cause conduction of heat through the blower motor. 

• remove humidity form the air inside if the cabin. 

Technician A says removing heat from an object or substance is simple, because cold always moves toward a warmer object. Technician B says all that is necessary for cooling is to provide an even warmer substance for cold to flow into. Who is correct? 

• TEch A

• Tech B

• Both A and B

• Neither A nor B

The thermal expansion valve device lowers the pressure of the warm, high-pressure liquid refrigerant entering the ___________. 

• Evaporator

• Condenser

• Compressor

• Orifice

Which of these holds true for H-Valve thermal expansion valve (TXV) operation?

• TVX meters the refrigerant into the evaporator at a variable rate. 

• It maintains the evaporator at low temperature and pressure.

• Spring tension acting on the orifice ball regulates the quality of refrigerant flow.

• Inlet temperature also can change the position of the linkage.

Technician A says accumulators often incorporate an important diagnostic aid—the refrigerant sight glass. Technician B says accumulators collect liquid refrigerant leaving the evaporator and separate vapor from liquid before the refrigerant enters the compressor. Who is correct? 

• Tech A

• Tech B

• Both A and B

• Neither A nor B

In a typical orifice tube system, which of the following indicates an undercharge of refrigerant? 

• Both the low and the high side gauges are running higher than normal. 

• The air-conditioning compressor clutch runs for a long time before it shuts off.

• The air in the ducts feels cold

• The air-conditioning clutch has a rapid cycle time

The air-conditioning box has a _____ that allows removal of water collected from the moist air as it condenses on the cold evaporator and drips into the box. 

• Collection grid

• Drain tube

• Window vent

• Level sensor

When servicing the vacuum pump, you will need a drain pan for the old oil and new vacuum pump oil for the vacuum pump. 

• True

• False