Prepare for the HVAC certification exam with these test answers. This guide covers refrigeration cycles, heating systems, air conditioning, and EPA 608 certification.

Q: Propane and Butane are _______ than air:

Answer: Heavier

Q: What will be the resistance in the circuit if the supply voltage is 30V and current flowing through the circuit is 5A

Answer: 6 ohms

Q: Temperature at which oil starts to produce a waxy substance that may interfere with the refrigeration system

Answer: Floc point

Q: What manifold gauge set is used to charge, evacuate, add oil and recover refrigerant from a refrigeration and air conditioning system?

Answer: Yellow hose

Q: Where is the oil separator located?

Answer: Discharge line

Q: Higher the ambient temperatures, ____ will be the evacuation time of the refrigerants from the system

Answer: Lesser

Q: 1 Watt is equal to

Answer: 3.41 Btu’s

Q: Heat that is absorbed or extracted when a substance changes its state is

Answer: Latent heat

Q: Where is the sight glass present in the refrigeration cycle?

Answer: Liquid line

Q: Which shall not be used near flammable materials?

Answer: Halide leak detector

Q: Current in a closed circuit is limited by:

Answer: Resistance

Q: When there is an increase in the heat load on the evaporator, the refrigerant will tend to evaporate at a _____ rate

Answer: Faster

Q: At what voltage is gas valve operates?

Answer: 24V

Q: Furnaces are placed into categories based upon

Answer: Venting characteristics

Q: What type of compressor uses two special helical rotors that introduce suction vapors then compress them?

Answer: Screw compressors

Q: 1 kWh of electric power is equivalent to how many Btu per hour:

Answer: 3412

Q: A high pressure steam boiler operates at a pressure greater than

Answer: 15 psig