Unit 43 #2

Which of the following metering devices has no moving parts?

• Capillary tube

• Piston

• Electronic expansion valve
  

• Thermostatic expansion valve

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

• check-type filter drier

• biflow filter drier

• counterflow filter drier

As an inverter-controlled compressor speeds up

• the suction pressure drops and the discharge pressure rises.

• the suction pressure and the discharge pressure drop

• the suction pressure rises and the discharge pressure drops.

• the suction pressure and the discharge pressure rise.

If a properly operating, conventional heat pump system is operating in the heating mode with an outside ambient temperature of 30°F, which of the following is the most likely outside coil temperature?

• 25°F

• 35°F

• –10°F

• 10°F

Which of the following statements is true regarding the coefficient of performance (COP) of a heat pump system?

• As the heat of compression (HOC) increases, the efficiency of the system decreases.

• As the compression ratio increases, the efficiency of the system increases.

• As the compression ratio increases, the heat of compression (HOC) decreases.

• As the heat of compression decreases, the compression ratio increases.

The coefficient of performance (COP) of electric strip heaters is closest to

• 2:1

• 4:1

• 1:1

• 3:1

What system conditions are likely to be observed if the heat pump's A-coil is located downstream of the electric strip heaters?

• High suction pressure and low discharge pressure
  

• High operating pressures

• Low suction pressure and high discharge pressure

• Low operating pressures
  

Which of the following is true regarding the discharge air temperature of a heat pump system operating in first-stage heating?

• The discharge air temperature is higher than that of an oil-fired heating system, but lower than that of a gas-fired heating system.
  

• The discharge air temperature is higher than that of both an oil-fired heating system and a gas-fired heating system.

• The discharge air temperature is lower than that of both an oil-fired heating system and a gas-fired heating system

• The discharge air temperature is higher than that of a gas-fired heating system, but lower than that of an oil-fired heating system.

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?

• Excessive ice buildup on the outdoor coil
  

• Higher than normal discharge pressure

• Higher than normal suction pressure

• Shortened defrost cycles
  

When a single metering device is used on a package heat pump system,

• it must be able to adjust refrigerant flow for the heating and cooling modes.
  

• it must be configured to meet the flow requirements for the heating mode.

• the capillary tube is the most popular choice.

• it must be configured to meet the flow requirements for the cooling mode.