Heat Pump Technology Flashcards
7 cards from real HVAC practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Heat Pump Technology flashcards as text
A ground-source heat pump uses the earth as a heat source in winter. What is the primary reason this is more efficient than an air-source heat pump in cold climates?
Answer: Ground temperature remains relatively stable and warmer than air temperature in winter
Below the frost line, ground temperatures remain relatively constant (typically 45–55°F in the US), providing a more favorable heat source than cold outdoor air in winter.
What is the function of the accumulator in a heat pump system?
Answer: To prevent liquid refrigerant from entering the compressor suction
The accumulator is installed on the suction line to separate liquid refrigerant from vapor, protecting the compressor from liquid slugging.
What type of heat pump system is BEST suited for a home without ductwork?
Answer: Mini-split ductless heat pump
Mini-split ductless heat pumps deliver conditioned air directly to individual zones without requiring ductwork, making them ideal for homes without existing ducts.
During a defrost cycle on a heat pump, auxiliary heat strips typically energize. Why?
Answer: To compensate for reduced heating capacity while the outdoor coil defrosts
During defrost, the system temporarily switches to cooling mode to melt frost, so auxiliary electric heat strips energize to maintain indoor comfort.
What does HSPF (Heating Seasonal Performance Factor) measure for a heat pump?
Answer: Total heating output divided by total electrical energy input over a heating season
HSPF is a seasonal efficiency rating for heat pumps in heating mode, calculated as total heating output (BTU) divided by total electricity consumed (Wh) over the heating season.
A technician measures suction pressure lower than normal and discharge pressure lower than normal during heat pump heating operation. What is the MOST likely cause?
Answer: Undercharge of refrigerant or low outdoor ambient temperature
Low suction and discharge pressures in heating mode typically indicate a low refrigerant charge or very low outdoor ambient temperature reducing the available heat source.
What is the purpose of a desuperheater in some heat pump systems?
Answer: To recover heat from hot discharge gas to preheat domestic hot water
A desuperheater uses the hot discharge gas from the compressor to preheat domestic hot water, improving overall system efficiency.