HVAC Midterm Questions and
Answers | Latest Version | 2025/2026 |
Correct & Verified
What is the difference between latent and sensible heat?
✔✔Latent heat relates to moisture changes, while sensible heat relates to temperature changes.
Why is refrigerant important in an air conditioning system?
✔✔It absorbs and releases heat to provide cooling.
What is the function of a compressor in a refrigeration cycle?
✔✔To raise refrigerant pressure and temperature for heat rejection.
What is the purpose of the evaporator coil?
✔✔To absorb heat from indoor air into the refrigerant.
What is the main role of the condenser coil?
✔✔To release heat from the refrigerant to the outside air.
What does SEER measure in air conditioning systems?
✔✔Cooling efficiency over an entire season.
Why is proper airflow critical in HVAC systems?
1
,✔✔To ensure efficient heat transfer and system performance.
What is superheat in a refrigeration system?
✔✔The temperature of refrigerant vapor above its boiling point.
What is subcooling in refrigeration?
✔✔The temperature of refrigerant liquid below its condensation point.
Why is regular maintenance of HVAC systems necessary?
✔✔To maintain efficiency, prevent breakdowns, and extend equipment life.
What is the purpose of a thermostat?
✔✔To control indoor temperature by cycling heating and cooling equipment.
What is a heat exchanger in a furnace?
✔✔A component that transfers heat from combustion gases to air without mixing them.
Why is duct insulation important?
✔✔To reduce heat loss or gain and improve energy efficiency.
What is a common symptom of a dirty air filter?
✔✔Reduced airflow and system efficiency.
2
, What is a variable-speed blower used for?
✔✔To adjust airflow based on system demand for comfort and efficiency.
What is a heat pump?
✔✔A system that can provide both heating and cooling using the same components.
Why is refrigerant recovery necessary before servicing a system?
✔✔To prevent environmental release and comply with EPA regulations.
What is the purpose of an expansion valve?
✔✔To regulate refrigerant flow into the evaporator.
What is a programmable thermostat?
✔✔A device that allows scheduled temperature changes to save energy.
What is the difference between a single-stage and two-stage furnace?
✔✔A single-stage furnace operates at full capacity, while a two-stage furnace can operate at low
or high settings for efficiency.
Why is grounding important in HVAC electrical systems?
✔✔To prevent electrical hazards and protect equipment.
3
Answers | Latest Version | 2025/2026 |
Correct & Verified
What is the difference between latent and sensible heat?
✔✔Latent heat relates to moisture changes, while sensible heat relates to temperature changes.
Why is refrigerant important in an air conditioning system?
✔✔It absorbs and releases heat to provide cooling.
What is the function of a compressor in a refrigeration cycle?
✔✔To raise refrigerant pressure and temperature for heat rejection.
What is the purpose of the evaporator coil?
✔✔To absorb heat from indoor air into the refrigerant.
What is the main role of the condenser coil?
✔✔To release heat from the refrigerant to the outside air.
What does SEER measure in air conditioning systems?
✔✔Cooling efficiency over an entire season.
Why is proper airflow critical in HVAC systems?
1
,✔✔To ensure efficient heat transfer and system performance.
What is superheat in a refrigeration system?
✔✔The temperature of refrigerant vapor above its boiling point.
What is subcooling in refrigeration?
✔✔The temperature of refrigerant liquid below its condensation point.
Why is regular maintenance of HVAC systems necessary?
✔✔To maintain efficiency, prevent breakdowns, and extend equipment life.
What is the purpose of a thermostat?
✔✔To control indoor temperature by cycling heating and cooling equipment.
What is a heat exchanger in a furnace?
✔✔A component that transfers heat from combustion gases to air without mixing them.
Why is duct insulation important?
✔✔To reduce heat loss or gain and improve energy efficiency.
What is a common symptom of a dirty air filter?
✔✔Reduced airflow and system efficiency.
2
, What is a variable-speed blower used for?
✔✔To adjust airflow based on system demand for comfort and efficiency.
What is a heat pump?
✔✔A system that can provide both heating and cooling using the same components.
Why is refrigerant recovery necessary before servicing a system?
✔✔To prevent environmental release and comply with EPA regulations.
What is the purpose of an expansion valve?
✔✔To regulate refrigerant flow into the evaporator.
What is a programmable thermostat?
✔✔A device that allows scheduled temperature changes to save energy.
What is the difference between a single-stage and two-stage furnace?
✔✔A single-stage furnace operates at full capacity, while a two-stage furnace can operate at low
or high settings for efficiency.
Why is grounding important in HVAC electrical systems?
✔✔To prevent electrical hazards and protect equipment.
3
