HVAC BOMA 501 ACTUAL EXAM QUESTIONS AND
ANSWERS TESTED AND APPROVED!!!
If a thermal expansion valve stays closed what would be the result --
ANSWER--The valve would not be the load and the unit will heat up
What type of metering device is used in a centrifugal chiller -- ANSWER--A
high side float
Which compressor require the least amount of maintenance -- ANSWER-
Centrifugal
What opens the TXV -- ANSWER--The power element of the assembly
T/F the purpose of a solenoid valve in a refrigeration system is to start and stop
the refrigerant flow -- ANSWER--True
What causes oil to foam -- ANSWER--Refrigerant in the oil
What determines the corrosion tendency of oil -- ANSWER--The sulfur content
What would cause a compressor to overload -- ANSWER--Starting under a
warm evaporator load
Page 1 of 71
,The evaporator im a refrigeration system -- ANSWER--Absorbs heat from the
product to be cooled
Moisture reacts with refrigerant and oil to form -- ANSWER--Acid
A direct expansion type evaporator is also called a -- ANSWER--Dry type
evaporator
The condenser -- ANSWER--rejects the heat from the refrigerant
Positive displacement compressors have crankcase heat to -- ANSWER-Prevent
the refrigerant migration to the compressor
If the power element of a TX valve loses its charge, the___. -- ANSWER-
refrigerant flow to the coil will stop
The pressure in a refrigeration system is changed in the -- ANSWER-
compressor and expansion device
What happens when room temperature soda is poured into a glass of ice ? --
ANSWER--The ice melts because it is absorbing heat from the soda .
Page 2 of 71
,If the power element of a TX valve loses its charge, the___. -- ANSWER-
refrigerant flow to the coil will stop
Most of the heat energy in the suction vapor entering the compressor is --
ANSWER--Latent heat
If the thermal bulb assembly develops a leak , what will occur -- ANSWER-The
bulb pressure will reduce and the valve will close
The compressor in a refrigeration system -- ANSWER--pumps the refrigerant
throughout the system
To control ice build - up on a heat pump outdoor coil in the heating cycle a
______ is used . -- ANSWER--pressure differential switch
The total pressure of a confined mixture of gases is the sum of the pressures of
each of the gases in the mixture . This is known as -- ANSWER--Dalton's Law
When moisture is present in a refrigeration system , it will react with the
refrigerant and the oil to form_ -- ANSWER--acid
A direct expansion - type evaporator is also called a -- ANSWER--dry-type
evaporator
Page 3 of 71
, Positive displacement compressors have crankcase heat to -- ANSWER-prevent
refrigerant migration to the compressor
If the power element of a TX valve loses its charge the -- ANSWER--refrigerant
flow to the coil will stop
Where is cooling produced -- ANSWER--In the evaporator
Where is heat content the highest -- ANSWER--Entering the compressor
Where is heat content decreased the most ? -- ANSWER--The condenser
Where is the compressor located -- ANSWER--Between the condenser and
evaporator
Where does the state of refrigerant change from liquid to a vapor -- ANSWER-
The evaporator
What part of the system is pressure the lowest -- ANSWER--The evaporator
Page 4 of 71
ANSWERS TESTED AND APPROVED!!!
If a thermal expansion valve stays closed what would be the result --
ANSWER--The valve would not be the load and the unit will heat up
What type of metering device is used in a centrifugal chiller -- ANSWER--A
high side float
Which compressor require the least amount of maintenance -- ANSWER-
Centrifugal
What opens the TXV -- ANSWER--The power element of the assembly
T/F the purpose of a solenoid valve in a refrigeration system is to start and stop
the refrigerant flow -- ANSWER--True
What causes oil to foam -- ANSWER--Refrigerant in the oil
What determines the corrosion tendency of oil -- ANSWER--The sulfur content
What would cause a compressor to overload -- ANSWER--Starting under a
warm evaporator load
Page 1 of 71
,The evaporator im a refrigeration system -- ANSWER--Absorbs heat from the
product to be cooled
Moisture reacts with refrigerant and oil to form -- ANSWER--Acid
A direct expansion type evaporator is also called a -- ANSWER--Dry type
evaporator
The condenser -- ANSWER--rejects the heat from the refrigerant
Positive displacement compressors have crankcase heat to -- ANSWER-Prevent
the refrigerant migration to the compressor
If the power element of a TX valve loses its charge, the___. -- ANSWER-
refrigerant flow to the coil will stop
The pressure in a refrigeration system is changed in the -- ANSWER-
compressor and expansion device
What happens when room temperature soda is poured into a glass of ice ? --
ANSWER--The ice melts because it is absorbing heat from the soda .
Page 2 of 71
,If the power element of a TX valve loses its charge, the___. -- ANSWER-
refrigerant flow to the coil will stop
Most of the heat energy in the suction vapor entering the compressor is --
ANSWER--Latent heat
If the thermal bulb assembly develops a leak , what will occur -- ANSWER-The
bulb pressure will reduce and the valve will close
The compressor in a refrigeration system -- ANSWER--pumps the refrigerant
throughout the system
To control ice build - up on a heat pump outdoor coil in the heating cycle a
______ is used . -- ANSWER--pressure differential switch
The total pressure of a confined mixture of gases is the sum of the pressures of
each of the gases in the mixture . This is known as -- ANSWER--Dalton's Law
When moisture is present in a refrigeration system , it will react with the
refrigerant and the oil to form_ -- ANSWER--acid
A direct expansion - type evaporator is also called a -- ANSWER--dry-type
evaporator
Page 3 of 71
, Positive displacement compressors have crankcase heat to -- ANSWER-prevent
refrigerant migration to the compressor
If the power element of a TX valve loses its charge the -- ANSWER--refrigerant
flow to the coil will stop
Where is cooling produced -- ANSWER--In the evaporator
Where is heat content the highest -- ANSWER--Entering the compressor
Where is heat content decreased the most ? -- ANSWER--The condenser
Where is the compressor located -- ANSWER--Between the condenser and
evaporator
Where does the state of refrigerant change from liquid to a vapor -- ANSWER-
The evaporator
What part of the system is pressure the lowest -- ANSWER--The evaporator
Page 4 of 71
