HVAC Excellence Questions and
Answers | Latest Version | 2025/2026 |
Correct & Verified
What is the function of an expansion valve in a refrigeration cycle?
✔✔To regulate refrigerant flow into the evaporator.
Why is refrigerant recovery necessary before servicing?
✔✔To prevent release of harmful chemicals and comply with EPA regulations.
What is the purpose of a condensate drain in an air conditioner?
✔✔To remove moisture collected from the air.
What is the function of a blower fan in an HVAC system?
✔✔To circulate air through ductwork and across heating/cooling coils.
What is a duct system designed to do?
✔✔Deliver conditioned air to occupied spaces efficiently.
What is a common cause of low refrigerant pressure?
✔✔Leak in the refrigerant line.
Why should air filters be changed regularly?
1
,✔✔To maintain airflow and indoor air quality.
What is a static pressure measurement used for in HVAC systems?
✔✔To determine resistance in ductwork and airflow restrictions.
What does the term “ventilation” refer to in HVAC?
✔✔The exchange of indoor air with outdoor air to maintain air quality.
Why is insulation important for refrigerant lines?
✔✔To prevent condensation and energy loss.
What is the role of a compressor in a refrigeration cycle?
✔✔To raise the pressure and temperature of the refrigerant vapor.
What is a common symptom of a dirty evaporator coil?
✔✔Reduced cooling efficiency.
Why are proper refrigerant charge levels critical?
✔✔To ensure optimal system performance and prevent damage.
What does a programmable thermostat allow?
✔✔Scheduling of temperature changes to save energy.
2
, What is the purpose of a safety limit switch in a furnace?
✔✔To shut off the system if temperatures exceed safe levels.
What is the difference between a split system and a packaged system?
✔✔A split system has separate indoor and outdoor units, while a packaged system combines
components in one unit.
What is a common cause of ice formation on an evaporator coil?
✔✔Restricted airflow or low refrigerant.
What does an economizer do in an HVAC system?
✔✔Uses outdoor air for cooling when conditions are favorable to save energy.
Why is proper duct sealing important?
✔✔To prevent air leaks and maintain system efficiency.
What is the purpose of a humidifier in an HVAC system?
✔✔To add moisture to indoor air for comfort.
What is the purpose of a dehumidifier in an HVAC system?
✔✔To remove excess moisture from indoor air.
3
Answers | Latest Version | 2025/2026 |
Correct & Verified
What is the function of an expansion valve in a refrigeration cycle?
✔✔To regulate refrigerant flow into the evaporator.
Why is refrigerant recovery necessary before servicing?
✔✔To prevent release of harmful chemicals and comply with EPA regulations.
What is the purpose of a condensate drain in an air conditioner?
✔✔To remove moisture collected from the air.
What is the function of a blower fan in an HVAC system?
✔✔To circulate air through ductwork and across heating/cooling coils.
What is a duct system designed to do?
✔✔Deliver conditioned air to occupied spaces efficiently.
What is a common cause of low refrigerant pressure?
✔✔Leak in the refrigerant line.
Why should air filters be changed regularly?
1
,✔✔To maintain airflow and indoor air quality.
What is a static pressure measurement used for in HVAC systems?
✔✔To determine resistance in ductwork and airflow restrictions.
What does the term “ventilation” refer to in HVAC?
✔✔The exchange of indoor air with outdoor air to maintain air quality.
Why is insulation important for refrigerant lines?
✔✔To prevent condensation and energy loss.
What is the role of a compressor in a refrigeration cycle?
✔✔To raise the pressure and temperature of the refrigerant vapor.
What is a common symptom of a dirty evaporator coil?
✔✔Reduced cooling efficiency.
Why are proper refrigerant charge levels critical?
✔✔To ensure optimal system performance and prevent damage.
What does a programmable thermostat allow?
✔✔Scheduling of temperature changes to save energy.
2
, What is the purpose of a safety limit switch in a furnace?
✔✔To shut off the system if temperatures exceed safe levels.
What is the difference between a split system and a packaged system?
✔✔A split system has separate indoor and outdoor units, while a packaged system combines
components in one unit.
What is a common cause of ice formation on an evaporator coil?
✔✔Restricted airflow or low refrigerant.
What does an economizer do in an HVAC system?
✔✔Uses outdoor air for cooling when conditions are favorable to save energy.
Why is proper duct sealing important?
✔✔To prevent air leaks and maintain system efficiency.
What is the purpose of a humidifier in an HVAC system?
✔✔To add moisture to indoor air for comfort.
What is the purpose of a dehumidifier in an HVAC system?
✔✔To remove excess moisture from indoor air.
3
