Hvac Midterm Exam Questions With Complete Solutions

HVAC MIDTERM EXAM QUESTIONS WITH
COMPLETE SOLUTIONS

One watt (1 W) of electrical energy is equivalent to ________ Btu's
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of heat energy. - CORRECT ANSWER✔✔-3.413 Btus
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Latent heat is also know as.
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A. Heat quantity
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B. Heat Intensity
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C. Hidden Heat
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D. Specific Heat - CORRECT ANSWER✔✔-C. Hidden Heat
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What is superheat?
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A. A vapor with a temperature above its saturation temperature.
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B. The temperature of refrigerant leaving the evaporator
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C. The temperature of refrigerant entering the compressor.
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,D. None of the above - CORRECT ANSWER✔✔-A. A vapor with a
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temperature above its saturation temperature. || || || ||




The indoor coil of a heat pump system serves as the _____ during
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the cooling season, and as the _____ during the heating season. -
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CORRECT ANSWER✔✔-evaporator, condenser || ||




In which component of a refrigeration system is heat removed? -
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CORRECT ANSWER✔✔-The Condenser || ||




What is the most common type of heat pump used in residential
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applications? - CORRECT ANSWER✔✔-Air-to-air split system || || || || ||




What indoor air volume (expressed in cfm) would be required for a
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heating unit that has a 50°F temperature rise and an output of
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80,000 Btuh? ||




|| * See formula page - CORRECT ANSWER✔✔-1481 cfm
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How much auxiliary heat will be required on a design day when a
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home's heat loss is 35,600 Btuh and the heat pump output is 17,200
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Btuh?
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|| * See formula page - CORRECT ANSWER✔✔-5.39 kW or 5,390 watts
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, Why does the indoor coil of a heat pump need more area than the
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indoor coil of a cooling-only unit? - CORRECT ANSWER✔✔-To
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prevent the condensing temperatures and corresponding head
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pressures from becoming too high during the heating cycle.
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Why does a heat pump require three-function control? - CORRECT
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ANSWER✔✔-Because a heat pump performs three functions-it || || || || || || ||



provides cooling, it provides heating, and it must defrost the
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outdoor coil when ice forms on it.
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What is the coefficient of performance (COP) of a heat pump? -
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CORRECT ANSWER✔✔-A comparison of how much heat the heat
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pump is producing compared to how much heat an electric furnace
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would produce using the same amount of electricity.
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What three types of compressors are used in residential heat pump
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applications? - CORRECT ANSWER✔✔-Reciprocating, scroll, and
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rotary.


Name two problems that occur when flash gas enters a TEV while a
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system is operating? - CORRECT ANSWER✔✔-The valve operates
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inefficiently, the system || ||




loses capacity, and superheat increases.
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