UNIT 64 REVIEW QUESTIONS ANSWER KEY GO BACK TO INDEX
64-1) List the types of heat pumps available by combinations of heat source and heat
sink. Air to air, water to air, air to water, water to water
64-2) Why is a heat pump called a heat pump?
64-3) How is the refrigeration cycle reversed in a heat pump?
64-4) Why are accumulators and/or charge compensator tanks necessary in air source
heat pumps?
64-5) Describe the operation of the reversing valve.
The solenoid coil controls the pilot valve that controls the pressure to the
64-6) What is the difference between an EER and an SEER?
64-7) What is the difference between a COP and an HSPF?
64-8) Why are the coils in an air source heat pump referred to as the outdoor coil and
indoor coil instead of the condenser and evaporator?
64-9) Explain why there is heat in the air even at cold temperatures.
64-10) List the physics principles that make heat pump operation possible.
Heat exists down to absolute zero, which is –460°F.
64-11) Why do most heat pumps have two metering devices?
64-12) What keeps both metering devices from being in the refrigeration circuit at the
same time?Check valves installed in parallel with the metering devices or built into
64-13) What is a bi-flow thermostatic expansion valve?
64-14) What is the difference between the defrost cycle and the coolingcycle?
64-15) Show the function of the coils by writing Evaporator or Condenser in the
appropriate box the following table.
64-16) Show the function of the metering devices by writing Active or Bypassed in the
appropriate box the following table.
64-17) Where is the permanent suction line always located on a reversing valve?
64-18) Where is the permanent discharge line always located?
64-19) Why are bi-flow filter driers used on heat pumps instead of standard filter driers?
64-20) How does a flow-check piston type metering device work?