A/C Study guide HVAC TCAT Exam 2025/2026 Questions With Completed & Verified Solutions.

A/C Study guide HVAC TCAT

_____ can be used for leak detection and is safe with all refrigerants - ANS Soap/bubble
solution
\10lbs of refrigerant pass through a water cooled condenser and gives up 20 BTU's of
heat per lb. At the same time, 10lb of water passes through with an entering temperature
of 80 degrees Fahrenheit the temperature of the water leaving the condenser is - ANS 100
Degrees Fahrenheit
\a clear sight glass could indicate
A)all liquid refrigerant
B)no refrigerant
C)either A or B
D) neither A nor B - ANS C)either A or B
\a compound pressure gauge measures - ANS pressure and vacuum
\a compressor that has a broken valve cause these symptoms
A)high suction pressure and low discharge pressure
B)high suction pressure and high discharge pressure
C)low suction pressure and low discharge pressure
D)low suction pressure and high discharge pressure - ANS A)high suction pressure and
low discharge pressure
\a condenser that is used in low ambient temperature conditions must have a method of
maintain a workable head pressure. This can be accomplished by
A)fan cycling
B)air shutters or dampers
C)condenser flooding
D)any of the above - ANS D)all of the above
\a customer calls on the first hot day in the spring and complains of no cooling. Upon
inspection your find that the sight glass indicates a full charge, the liquid line is hot, and
the unit is cycling on the motor internal overloads. this could be caused by
A)an overcharge of refrigerant
B)a dirty condenser
C)an inoperative condenser fan
D)any of the above - ANS D)any of the above
\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

TECH A says this could be caused by low refrigerant charge and needs to be leak tested
and repaired.

TECH B says that these symptoms could indicate restricted return air flow or a dirty
evaporator. Whos correct?

, A)tech a
B)tech b
C)both
D)neither - ANS B)tech B
\a customer reports that their 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 condensing unit, you find that the liquid line is
sweating where it leaves the drier. this is most likely the result of - ANS debris from the
burned out compressor has a clogged the drier
\a decrease in superheat causes the thermostatic expansion valve to
A)open
B)close
C)fail
D)none of the above - ANS B)close
\a dirty evaporator in an air conditioning system will cause these symptoms
A)high suction pressure and low discharge pressure
B)high suction pressure and high discharge pressure
C)low suction pressure and low discharge pressure
D)low suction pressure and high discharge pressure - ANS C)low suction pressure and
low discharge pressure
\a faulty condenser fan motor on an air conditioning system will cause these symptoms
A)high suction pressure and low discharge pressure
B)high suction pressure and high discharge pressure
C)low suction pressure and low discharge pressure
D)low suction pressure and high discharge pressure - ANS B)high suction pressure and
high discharge pressure
\a hermetic system that is low on charge is indicated by
A)a partially frosted evaporator
B)low head pressure
C)low suction pressure
D)all of the above - ANS D)all of the above
\a liquid line filter-drier should be placed - ANS between the condenser and the metering
device
\a liquid receiver is used - ANS to store liquid refrigerant
\a liquid-to-suction heat exchanger is often used to - ANS increase sub-cooling
\a low pressure cut-off switch is used to - ANS establish a minimum operating pressure
in the evaporator
\a low refrigerant charge in the air conditioning system will cause these symptoms
A)high suction pressure and low discharge pressure
B)high suction pressure and high discharge pressure
C)low suction pressure and low discharge pressure
D)low suction pressure and high discharge pressure - ANS C)low suction pressure and
low discharge pressure
\a low-side float metering device is used; - ANS on a flooded evaporator