Unit 43 review question

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?

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

  
  

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

  
  

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

  
  

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

  
  

The filter drier that operates as two filter driers in one casing to filter refrigerant flowing in either direction is called the

• bypass filter drier

• counterflow filter drier

• biflow filter drier

• check-type filter drier.

An air-to-air heat pump operating in the heating mode might experience which of the following if it is installed in an area that is near a lake or other body of water?

• Shortened defrost cycles

• Excessive ice buildup on the outdoor coil

• Higher than normal suction pressure

• Higher than normal discharge pressure

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

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

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

• high-pressure liquid 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.

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

• 0%

• 85%

• 23%

• 57%

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

• air to cool water.

• air to heat water.

• water to heat air.

• water to cool air.

During defrost, what percentage of the heat pump system's cooling capacity should be offset by the electric strip heaters?

• 40%

• 80%

• 60%

• 20%

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

• Emergency heat

• Defrost

• Cooling

• Heating

One benefit of using scroll compressors instead of reciprocating compressors to increase heat pump system efficiency is that scroll compressors

• are cooled by suction gas.

• do not have "top-of-the-stroke" clearance volume losses.

• are lighter than reciprocating compressors.

• do not require a suction-line accumulator.

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?

• Biflow valve

• Check valve

• Counterflow valve

• Bypass valve