Unit 43 Heat pumps

Which component of a heat pump is responsible for changing the direction of refrigerant flow through the system?

• Compressor

• Check valve

• Reversing valve

• Metering device

Which of the following statements is true regarding heat pump system operation

• The indoor coil functions as the evaporator in the heating mode.

• The indoor coil functions as the condenser in the heating mode.

• The outdoor coil functions as the condenser in the heating mode.

• The outdoor coil functions as the evaporator in the cooling mode.

An air-to-water heat pump system uses heat contained in

• air to heat water.

• water to cool air.

• air to cool water.

• water to heat air.

What is the approximate percentage of usable heat that remains in outside air when it drops to a temperature of 0°F?

• 57%

• 0%

• 85%

• 23%

The majority of heat pump systems will operate in which mode when the reversing valve's solenoid is deenergized?

• Emergency heat

• Heating
  

• Defrost
  

• Cooling

The isolated port on a reversing valve contains high-pressure

• gas that is leaving the valve flowing to the compressor.

• liquid that is entering the valve from the compressor.

• liquid that is leaving the valve flowing to the compressor.
  

• gas that is entering the valve from the compressor

A reversing valve that relies on the system's operating pressures to change the position of the valve is called a

• indirectly controlled reversing valve.

• direct-acting reversing valve.
  

• pressure-activated reversing valve.
  

• pilot-operated reversing valve.
  

On a split-type heat pump system, the larger field-installed line carries

• high-pressure liquid in the heating mode and low-pressure gas in the cooling mode.

• high-pressure gas in the heating mode and low-pressure gas in the cooling mode

• high-pressure gas in the cooling mode and low-pressure gas in the heating mode.

• high-pressure liquid in the cooling mode and high-pressure gas in the heating mode.

On ductless split-type heat pump system, which of the following statements is true regarding the field-installed refrigerant lines if the system is operating in the heating mode?

• The larger line will contain high-pressure, high-temperature vapor.

• The smaller line will contain high-pressure, high-temperature vapor.

• The smaller line will contain low-pressure, low-temperature vapor.

• The larger line will contain low-pressure, low-temperature vapor.

What device is often used in conjunction with a thermostatic expansion valve that allows refrigerant to flow in the opposite direction, bypassing the valve's needle and seat assembly?

• Bypass valve

• Counterflow valve

• Check valve

• Biflow valve