ESCO Air Conditioning Exam
1. Leak Detection and Pressure
Q1: _________ can be used for leak detection with all high-pressure
refrigerant.
● A) Electronic leak detector only
● B) Soap bubbles
● C) Halide torch
● D) Ultrasonic detector
Answer: B) Soap bubbles
Q2: 0 pounds per square inch absolute is:
● A) The same as atmospheric pressure
● B) A pressure which cannot be further reduced
● C) Equal to 14.7 psia
● D) A vacuum of 29.92 inches Hg
Answer: B) A pressure which cannot be further reduced
Q3: 0 pounds per square inch gauge is:
● A) A perfect vacuum
● B) The same as atmospheric pressure
● C) Equal to 14.7 psia
● D) A negative pressure
Answer: B) The same as atmospheric pressure
2. Heat Transfer and BTU Calculations
Q4: 10 pounds of refrigerant passing through a water cooled condenser will
lose 20 BTUs of heat per pound. If 10 pounds of water passes through the
condenser with an entering temperature of 80°F, the temperature of the water
leaving the condenser is:
, ● A) 90°F
● B) 95°F
● C) 100°F
● D) 110°F
Answer: C) 100°F
3. Gauges and Instruments
Q5: A compound pressure gauge measures:
● A) Pressure only
● B) Vacuum only
● C) Pressure and vacuum
● D) Temperature and pressure
Answer: C) Pressure and vacuum
4. Compressor Issues
Q6: A compressor that has a broken reed valve will cause the symptoms:
● A) Low suction pressure and high discharge pressure
● B) High suction pressure and low discharge pressure
● C) High suction pressure and high discharge pressure
● D) Low suction pressure and low discharge pressure
Answer: B) High suction pressure and low discharge pressure
Q7: A customer complains that their air conditioning system is running
constantly, but not cooling enough. The suction line is very cold and the
compressor is sweating. The most likely cause is:
● A) Low refrigerant charge
● B) A restriction of the return air or a dirty evaporator
● C) Overcharged system
● D) Faulty compressor
Answer: B) A restriction of the return air or a dirty evaporator
, Q8: A customer reports that the residential split system had a compressor
replaced last week by another service company. Now the unit is not cooling
properly. When you arrive and inspect the unit you find that the evaporator
seems to be starved for refrigerant. On examining the condensing unit, you
find that the liquid line is sweating where it leaves the dryer. This is most likely
the result of:
● A) Low refrigerant charge
● B) Faulty TXV
● C) Debris from the burned out compressor has clogged the dryer
● D) Incorrect refrigerant type
Answer: C) Debris from the burned out compressor has clogged the dryer
5. Expansion Valves
Q9: A decrease in superheat causes the thermostatic expansion valve to begin
to:
● A) Open
● B) Close
● C) Remain unchanged
● D) Cycle rapidly
Answer: B) Close
Q10: A rise in evaporator pressure causes the automatic expansion valve to
begin to:
● A) Open
● B) Close
● C) Remain unchanged
● D) Increase flow
Answer: B) Close
Q11: A thermal electric expansion valve is controlled by:
1. Leak Detection and Pressure
Q1: _________ can be used for leak detection with all high-pressure
refrigerant.
● A) Electronic leak detector only
● B) Soap bubbles
● C) Halide torch
● D) Ultrasonic detector
Answer: B) Soap bubbles
Q2: 0 pounds per square inch absolute is:
● A) The same as atmospheric pressure
● B) A pressure which cannot be further reduced
● C) Equal to 14.7 psia
● D) A vacuum of 29.92 inches Hg
Answer: B) A pressure which cannot be further reduced
Q3: 0 pounds per square inch gauge is:
● A) A perfect vacuum
● B) The same as atmospheric pressure
● C) Equal to 14.7 psia
● D) A negative pressure
Answer: B) The same as atmospheric pressure
2. Heat Transfer and BTU Calculations
Q4: 10 pounds of refrigerant passing through a water cooled condenser will
lose 20 BTUs of heat per pound. If 10 pounds of water passes through the
condenser with an entering temperature of 80°F, the temperature of the water
leaving the condenser is:
, ● A) 90°F
● B) 95°F
● C) 100°F
● D) 110°F
Answer: C) 100°F
3. Gauges and Instruments
Q5: A compound pressure gauge measures:
● A) Pressure only
● B) Vacuum only
● C) Pressure and vacuum
● D) Temperature and pressure
Answer: C) Pressure and vacuum
4. Compressor Issues
Q6: A compressor that has a broken reed valve will cause the symptoms:
● A) Low suction pressure and high discharge pressure
● B) High suction pressure and low discharge pressure
● C) High suction pressure and high discharge pressure
● D) Low suction pressure and low discharge pressure
Answer: B) High suction pressure and low discharge pressure
Q7: A customer complains that their air conditioning system is running
constantly, but not cooling enough. The suction line is very cold and the
compressor is sweating. The most likely cause is:
● A) Low refrigerant charge
● B) A restriction of the return air or a dirty evaporator
● C) Overcharged system
● D) Faulty compressor
Answer: B) A restriction of the return air or a dirty evaporator
, Q8: A customer reports that the residential split system had a compressor
replaced last week by another service company. Now the unit is not cooling
properly. When you arrive and inspect the unit you find that the evaporator
seems to be starved for refrigerant. On examining the condensing unit, you
find that the liquid line is sweating where it leaves the dryer. This is most likely
the result of:
● A) Low refrigerant charge
● B) Faulty TXV
● C) Debris from the burned out compressor has clogged the dryer
● D) Incorrect refrigerant type
Answer: C) Debris from the burned out compressor has clogged the dryer
5. Expansion Valves
Q9: A decrease in superheat causes the thermostatic expansion valve to begin
to:
● A) Open
● B) Close
● C) Remain unchanged
● D) Cycle rapidly
Answer: B) Close
Q10: A rise in evaporator pressure causes the automatic expansion valve to
begin to:
● A) Open
● B) Close
● C) Remain unchanged
● D) Increase flow
Answer: B) Close
Q11: A thermal electric expansion valve is controlled by:
