CFESA -Commercial- Refrigeration
Certification -Study Guide Questions
with Quality Answers 2026 Update.
Approximately how much Air flow is required across an air-cooled condenser? - Answer 750-
1000 CFM Per Ton of Cooling Capacity
A sling psycrometer is used to measure.....? - Answer Wet and dry bulb temperature
The capacity of an evaporative condenser depends on....? - Answer The Entering Air Wet Bulb
Temperature
Hot Gas Bypass refers to....? - Answer All of Above (Preventing low suction pressure, Providing
Capacity Control, Preventing Compressor short Cycling.)
A compressor is operating with a discharge pressure of 185.3 PSIG and a suction pressure of
25.3 PSIG. The compression ratio (Pumping Ratio) is.....? - Answer 5:1
Wet bulb depression is.....? - Answer The difference between Wet bulb and Dry Bulb
Temperatures
A compressor net oil pressure is determined by.....? - Answer Oil pump discharge pressure
minus the Suction Pressure
Some compressors are fitted with an unloading device to provide variable capacity. Variable
Capacity is necessary to......? - Answer All of above (Prevent Undesirably low evaporator
pressures, Prevent evaporator coil frost, & Prevent Compressor short Cycling)
Refrigerant in the suction line should be slightly superheated in order to.......? - Answer Insure
liquid refrigerant does not enter the Compressor
A decrease in water flow, when using a water cooled condenser....? - Answer Increase the
power consumtion of the compressor
If a TEV sensing bulb lost its charge, what effect would this moment have on the AC system? -
Answer Both A and B(It would cause high side pressure to increase and cause low side to
decrease)
, The amount of heat absorbed in the evaporator is equal to....? - Answer The heat in the
conditioned space
Approximately how much airflow is required across the evaporator per ton of cooling capacity? -
Answer 350-400 CFM Per Ton
The most reliable and safest method of field charging a system is.....? - Answer To charge by
weight according to manufacturer specifications
On split system installations, the suction line should be pitched towards the compressor at
least....? - Answer One inch per 10 feet (1 inch/10ft)
Polyolester oils---? - Answer All of Above (hold moisture tightly, so more evacuation time may
be necessary, Have similar lubricity and miscibility characteristics as mineral oil, and Absorb
atmospheric moisture more easily than mineral oil)
When sizing an oil tower, it is important to know that one pound of evaporating water can
absorb....? - Answer 970 BTU's
Depending on the application, the suction lines may be ______________ to assure proper oil
return. - Answer Trapped
When an AC unit has a suction line that is frosted up on the compressor, what faults could
occur? - Answer All of Above (Bad indoor blower relay, a plugged Air Filter, or A dirty
evaporator Coil)
Upon investigation of a "No Cooling" complaint, the technician finds that the blower motor of
the air handler has open windings. One week ago, the same unit was found to have a broken
belt caused by a worn drive pulley. Both the belt and pulley were replaced at that time. The
technician decides to replace the motor and .....? - Answer Check for proper Amp Draw)
What is the purpose of the distributor....? - Answer It evenly feeds refrigerant to the
evpaorator
High compressor operating temperatures can be caused by.....? - Answer All of Above (Low
Volumetric Efficiency, Low Suction Pressures, and High Compression Ratio)
The clearance space in a reciprocating compressor....? - Answer Has an effect on compressor
capacity
Certification -Study Guide Questions
with Quality Answers 2026 Update.
Approximately how much Air flow is required across an air-cooled condenser? - Answer 750-
1000 CFM Per Ton of Cooling Capacity
A sling psycrometer is used to measure.....? - Answer Wet and dry bulb temperature
The capacity of an evaporative condenser depends on....? - Answer The Entering Air Wet Bulb
Temperature
Hot Gas Bypass refers to....? - Answer All of Above (Preventing low suction pressure, Providing
Capacity Control, Preventing Compressor short Cycling.)
A compressor is operating with a discharge pressure of 185.3 PSIG and a suction pressure of
25.3 PSIG. The compression ratio (Pumping Ratio) is.....? - Answer 5:1
Wet bulb depression is.....? - Answer The difference between Wet bulb and Dry Bulb
Temperatures
A compressor net oil pressure is determined by.....? - Answer Oil pump discharge pressure
minus the Suction Pressure
Some compressors are fitted with an unloading device to provide variable capacity. Variable
Capacity is necessary to......? - Answer All of above (Prevent Undesirably low evaporator
pressures, Prevent evaporator coil frost, & Prevent Compressor short Cycling)
Refrigerant in the suction line should be slightly superheated in order to.......? - Answer Insure
liquid refrigerant does not enter the Compressor
A decrease in water flow, when using a water cooled condenser....? - Answer Increase the
power consumtion of the compressor
If a TEV sensing bulb lost its charge, what effect would this moment have on the AC system? -
Answer Both A and B(It would cause high side pressure to increase and cause low side to
decrease)
, The amount of heat absorbed in the evaporator is equal to....? - Answer The heat in the
conditioned space
Approximately how much airflow is required across the evaporator per ton of cooling capacity? -
Answer 350-400 CFM Per Ton
The most reliable and safest method of field charging a system is.....? - Answer To charge by
weight according to manufacturer specifications
On split system installations, the suction line should be pitched towards the compressor at
least....? - Answer One inch per 10 feet (1 inch/10ft)
Polyolester oils---? - Answer All of Above (hold moisture tightly, so more evacuation time may
be necessary, Have similar lubricity and miscibility characteristics as mineral oil, and Absorb
atmospheric moisture more easily than mineral oil)
When sizing an oil tower, it is important to know that one pound of evaporating water can
absorb....? - Answer 970 BTU's
Depending on the application, the suction lines may be ______________ to assure proper oil
return. - Answer Trapped
When an AC unit has a suction line that is frosted up on the compressor, what faults could
occur? - Answer All of Above (Bad indoor blower relay, a plugged Air Filter, or A dirty
evaporator Coil)
Upon investigation of a "No Cooling" complaint, the technician finds that the blower motor of
the air handler has open windings. One week ago, the same unit was found to have a broken
belt caused by a worn drive pulley. Both the belt and pulley were replaced at that time. The
technician decides to replace the motor and .....? - Answer Check for proper Amp Draw)
What is the purpose of the distributor....? - Answer It evenly feeds refrigerant to the
evpaorator
High compressor operating temperatures can be caused by.....? - Answer All of Above (Low
Volumetric Efficiency, Low Suction Pressures, and High Compression Ratio)
The clearance space in a reciprocating compressor....? - Answer Has an effect on compressor
capacity
