Why are thermostatic expansion valves often used as the outdoor metering device for the heating cycle?
A) TEVs can be adjusted in the field to match the heat pump's performance with the climate it will be operating in.
B) TEVs are easier to install on the outdoor coil.
C) TEVs allow the system pressures to equalize in the off cycle, allowing the use of low starting torque compressors.
D) The TEV can modulate the refrigerant flow over the wide range of temperatures experienced in the heating mode.
[Ques. 2] What air property is measured in grains?
A) The weight of air.
B) Wet-bulb temperatures.
C) Grains are used to measure the amount of water in the air.
D) Relative humidity.
[Ques. 3] What effect do volatile liquids stored near the furnace have on its performance?
A) They damage vent work. B) They can produce flammable vapors.
C) They help to create carbon monoxide. D) They corrode furnace components.
[Ques. 4] The International Green Construction Code (IGCC) is unique in its approach because it is:
A) Required by most banks to obtain a construction loan.
B) Available free of charge on the Department of Energy website.
C) The only Green construction code.
D) A collaboration of five separate agencies with different areas of expertise.
[Ques. 5] What effect do noncondensable gases have on system performance?
A) They cause an increase in head pressure and a decrease in capacity.
B) They cause a decrease in head pressure and an increase in capacity.
C) Noncondensables do not affect condenser pressure because they do not condense.
D) They cause a decrease in both head pressure and capacity.
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