Cfesa-CFQ -review Questions with
Guaranteed Pass Solutions 2026/2027
Updated.
C of Q Prep Course - Answer
Heating, Ventilation, Air Conditioning and Refrigeration (HVACR) Mechanic - Answer
Level 3 HVACR Review - Answer
L3-C 21.0 Air conditioning systems - Answer
1) - Answer State the approximate melting point for the following:
• - Answer 95/5 Solder: 450 - 465F
• - Answer Silver Solder: 1120 - 1145F
• - Answer Silfos: 1310 - 1650F
2) - Answer What type of brazing alloy would you recommend for joining copper tubing to a
brass shut off valve:
• - Answer Silver solder brazing alloy
3) - Answer Why must flex be used when brazing with silver solder?
• - Answer Prevents oxides from forming inside the pipe
4) - Answer Why must flux be removed after brazing with silver solder?
• - Answer Flux is corrosive and in time will cause the base metal to disintegrate
5) - Answer Convert the following pressures
,• - Answer 12psia to 5.5"HG
• - Answer 14.7psig to 29.4 PSIA
6) - Answer Calculate the amount of heat that must be removed from 10 lb of steam at 218F
to convert it to ice at 12F
• - Answer 13087.6 BTU
7) - Answer Explain the following:
• - Answer Superheat:
o - Answer Sensible heat added to a vapour above saturation
• - Answer Specific heat:
o - Answer The amount of heat required to change the temperature of one pound of a
substance one degree Fahrenheit
• - Answer Sensible heat:
o - Answer Heat which when added to a material raises its temperature
• - Answer Latent heat:
o - Answer The amount of heat required to cause a change of state without a change in
temperature also referred to as hidden heat
• - Answer Conduction:
o - Answer Heat flow through a material by contact between the molecules of a substance.
• - Answer Hydrometer:
,o - Answer Instrument for measuring specific gravity, measures relative density. (Hygrometer
measures relative humidity)
• - Answer Manometer:
o - Answer Instrument for measuring inches of water column
• - Answer Barometer:
o - Answer Instrument for measuring barometric pressure
• - Answer The three gas laws:
• - Answer BTUH / Horsepower
8) - Answer How many tons of refrigeration would be required to cool 10 imperial gallons of
water from 80F to 40F in 60 minutes:
• - Answer 10 x 10 = 100lbs. Q = wt x sh x (t2-t1). 100 x 1 x 40 = 4000BTU's. 4000/12000 =
0.33lb
9) - Answer How many pounds of refrigerant can be stored in a mechanical room according to
the B52?
• - Answer 300lb
10) - Answer How would you test a head pressure control?
• - Answer Disengage the condenser fan
11) - Answer How much slope is allowed per 10 feet of refrigeration suction line?
• - Answer 1 inch per 20 feet. Sloped in the direction of flow
12) - Answer Why do air to air heat pumps usually require an accumulator?
, • - Answer Because the evaporators will freeze up when they run below 32 degrees saturation
13) - Answer What accessory could be added to a refrigeration system to eliminate excessive
flash gas in the liquid line?
• - Answer Liquid to suction heat exchanger. Subcools the liquid refrigerant. Not to be used
with R22 systems, SV of gas goes up too much.
14) - Answer A winter head pressure control valve is installed in the _____ line and is designed
to:
• - Answer Condensate line. Flood the condenser to maintain adequate head pressure during
low ambient temperature conditions.
15) - Answer When removing the gauge port plug from a compressor service valve the valve
should be front seated, back seated or cracked.
• - Answer Back seated
16) - Answer An EPR valve is located in the _________ line and is designed to:
• - Answer Suction Line
• - Answer Maintain a minimum SST in an evaporator
• - Answer Controlled by upstream pressure, opens on rise of upstream pressure
• - Answer EPR installed on outlet of warmest evaporator
• - Answer Check valve required on lower temperature box to prevent oil migration
17) - Answer A CPR valve is located in the _______ line and is designed to:
• - Answer Suction line
• - Answer Prevent compressor overload during warm start up. (initial start up, after repairs or
following defrost)
Guaranteed Pass Solutions 2026/2027
Updated.
C of Q Prep Course - Answer
Heating, Ventilation, Air Conditioning and Refrigeration (HVACR) Mechanic - Answer
Level 3 HVACR Review - Answer
L3-C 21.0 Air conditioning systems - Answer
1) - Answer State the approximate melting point for the following:
• - Answer 95/5 Solder: 450 - 465F
• - Answer Silver Solder: 1120 - 1145F
• - Answer Silfos: 1310 - 1650F
2) - Answer What type of brazing alloy would you recommend for joining copper tubing to a
brass shut off valve:
• - Answer Silver solder brazing alloy
3) - Answer Why must flex be used when brazing with silver solder?
• - Answer Prevents oxides from forming inside the pipe
4) - Answer Why must flux be removed after brazing with silver solder?
• - Answer Flux is corrosive and in time will cause the base metal to disintegrate
5) - Answer Convert the following pressures
,• - Answer 12psia to 5.5"HG
• - Answer 14.7psig to 29.4 PSIA
6) - Answer Calculate the amount of heat that must be removed from 10 lb of steam at 218F
to convert it to ice at 12F
• - Answer 13087.6 BTU
7) - Answer Explain the following:
• - Answer Superheat:
o - Answer Sensible heat added to a vapour above saturation
• - Answer Specific heat:
o - Answer The amount of heat required to change the temperature of one pound of a
substance one degree Fahrenheit
• - Answer Sensible heat:
o - Answer Heat which when added to a material raises its temperature
• - Answer Latent heat:
o - Answer The amount of heat required to cause a change of state without a change in
temperature also referred to as hidden heat
• - Answer Conduction:
o - Answer Heat flow through a material by contact between the molecules of a substance.
• - Answer Hydrometer:
,o - Answer Instrument for measuring specific gravity, measures relative density. (Hygrometer
measures relative humidity)
• - Answer Manometer:
o - Answer Instrument for measuring inches of water column
• - Answer Barometer:
o - Answer Instrument for measuring barometric pressure
• - Answer The three gas laws:
• - Answer BTUH / Horsepower
8) - Answer How many tons of refrigeration would be required to cool 10 imperial gallons of
water from 80F to 40F in 60 minutes:
• - Answer 10 x 10 = 100lbs. Q = wt x sh x (t2-t1). 100 x 1 x 40 = 4000BTU's. 4000/12000 =
0.33lb
9) - Answer How many pounds of refrigerant can be stored in a mechanical room according to
the B52?
• - Answer 300lb
10) - Answer How would you test a head pressure control?
• - Answer Disengage the condenser fan
11) - Answer How much slope is allowed per 10 feet of refrigeration suction line?
• - Answer 1 inch per 20 feet. Sloped in the direction of flow
12) - Answer Why do air to air heat pumps usually require an accumulator?
, • - Answer Because the evaporators will freeze up when they run below 32 degrees saturation
13) - Answer What accessory could be added to a refrigeration system to eliminate excessive
flash gas in the liquid line?
• - Answer Liquid to suction heat exchanger. Subcools the liquid refrigerant. Not to be used
with R22 systems, SV of gas goes up too much.
14) - Answer A winter head pressure control valve is installed in the _____ line and is designed
to:
• - Answer Condensate line. Flood the condenser to maintain adequate head pressure during
low ambient temperature conditions.
15) - Answer When removing the gauge port plug from a compressor service valve the valve
should be front seated, back seated or cracked.
• - Answer Back seated
16) - Answer An EPR valve is located in the _________ line and is designed to:
• - Answer Suction Line
• - Answer Maintain a minimum SST in an evaporator
• - Answer Controlled by upstream pressure, opens on rise of upstream pressure
• - Answer EPR installed on outlet of warmest evaporator
• - Answer Check valve required on lower temperature box to prevent oil migration
17) - Answer A CPR valve is located in the _______ line and is designed to:
• - Answer Suction line
• - Answer Prevent compressor overload during warm start up. (initial start up, after repairs or
following defrost)
