BOMA HVAC Exam Questions and Answers With Verified Solutions 2025
What happens when room temperature soda is poured into a glass of ice ? - ✔✔The ice melts because it
is absorbing heat from the soda .
The compressor in a refrigeration system - ✔✔pumps the refrigerant throughout the system
To control ice build - up on a heat pump outdoor coil in the heating cycle a ______ is used . -
✔✔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 - ✔✔Dalton's Law
When moisture is present in a refrigeration system , it will react with the refrigerant and the oil to form_
- ✔✔acid
A direct expansion - type evaporator is also called a - ✔✔dry-type evaporator
Positive displacement compressors have crankcase heat to - ✔✔prevent refrigerant migration to the
compressor
If the power element of a TX valve loses its charge the - ✔✔refrigerant flow to the coil will stop
The pressure in a refrigeration system is changed in the - ✔✔compressor and expansion device
Where is cooling produced - ✔✔In the evaporator
Where is heat content the highest - ✔✔Entering the compressor
Where is heat content decreased the most ? - ✔✔The condenser
,Where is the compressor located - ✔✔Between the condenser and evaporator
Where does the state of refrigerant change from liquid to a vapor - ✔✔The evaporator
What part of the system is pressure the lowest - ✔✔The evaporator
(T/F) A Compressor raises the pressure and lowers the temperature of the refrigerant - ✔✔False
Rotary is what type compressor - ✔✔Positive displacement
If a thermal expansion valve stays closed what would be the result - ✔✔The valve would not be the load
and the unit will heat up
What type of metering device is used in a centrifugal chiller - ✔✔A high side float
Which compressor require the least amount of maintenance - ✔✔Centrifugal
What opens the TXV - ✔✔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 -
✔✔True
What causes oil to foam - ✔✔Refrigerant in the oil
What determines the corrosion tendency of oil - ✔✔The sulfur content
What would cause a compressor to overload - ✔✔Starting under a warm evaporator load
, The evaporator im a refrigeration system - ✔✔Absorbs heat from the product to be cooled
Moisture reacts with refrigerant and oil to form - ✔✔Acid
A direct expansion type evaporator is also called a - ✔✔Dry type evaporator
The condenser - ✔✔rejects the heat from the refrigerant
Positive displacement compressors have crankcase heat to - ✔✔Prevent the refrigerant migration to the
compressor
If the power element of a TX valve loses its charge, the___. - ✔✔refrigerant flow to the coil will stop
Most of the heat energy in the suction vapor entering the compressor is - ✔✔Latent heat
If the thermal bulb assembly develops a leak , what will occur - ✔✔The bulb pressure will reduce and
the valve will close
The approach of a cooling tower is the - ✔✔difference in temperature between the entering air wet-
bulb temperature and the sump water temperature
At what locations in a refrigeration system does the saturation pressure correspond to the saturation
temperature - ✔✔Evaporator and condenser
A split phase motor can use what to energize and de-energize the start winding ? - ✔✔Potential relay,
current relay, and a centrifugal switch
Temperature is an indicaron of the - ✔✔Amount of molecular activity in the material
What can cause high suction pressures - ✔✔Defective compressor valves
What happens when room temperature soda is poured into a glass of ice ? - ✔✔The ice melts because it
is absorbing heat from the soda .
The compressor in a refrigeration system - ✔✔pumps the refrigerant throughout the system
To control ice build - up on a heat pump outdoor coil in the heating cycle a ______ is used . -
✔✔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 - ✔✔Dalton's Law
When moisture is present in a refrigeration system , it will react with the refrigerant and the oil to form_
- ✔✔acid
A direct expansion - type evaporator is also called a - ✔✔dry-type evaporator
Positive displacement compressors have crankcase heat to - ✔✔prevent refrigerant migration to the
compressor
If the power element of a TX valve loses its charge the - ✔✔refrigerant flow to the coil will stop
The pressure in a refrigeration system is changed in the - ✔✔compressor and expansion device
Where is cooling produced - ✔✔In the evaporator
Where is heat content the highest - ✔✔Entering the compressor
Where is heat content decreased the most ? - ✔✔The condenser
,Where is the compressor located - ✔✔Between the condenser and evaporator
Where does the state of refrigerant change from liquid to a vapor - ✔✔The evaporator
What part of the system is pressure the lowest - ✔✔The evaporator
(T/F) A Compressor raises the pressure and lowers the temperature of the refrigerant - ✔✔False
Rotary is what type compressor - ✔✔Positive displacement
If a thermal expansion valve stays closed what would be the result - ✔✔The valve would not be the load
and the unit will heat up
What type of metering device is used in a centrifugal chiller - ✔✔A high side float
Which compressor require the least amount of maintenance - ✔✔Centrifugal
What opens the TXV - ✔✔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 -
✔✔True
What causes oil to foam - ✔✔Refrigerant in the oil
What determines the corrosion tendency of oil - ✔✔The sulfur content
What would cause a compressor to overload - ✔✔Starting under a warm evaporator load
, The evaporator im a refrigeration system - ✔✔Absorbs heat from the product to be cooled
Moisture reacts with refrigerant and oil to form - ✔✔Acid
A direct expansion type evaporator is also called a - ✔✔Dry type evaporator
The condenser - ✔✔rejects the heat from the refrigerant
Positive displacement compressors have crankcase heat to - ✔✔Prevent the refrigerant migration to the
compressor
If the power element of a TX valve loses its charge, the___. - ✔✔refrigerant flow to the coil will stop
Most of the heat energy in the suction vapor entering the compressor is - ✔✔Latent heat
If the thermal bulb assembly develops a leak , what will occur - ✔✔The bulb pressure will reduce and
the valve will close
The approach of a cooling tower is the - ✔✔difference in temperature between the entering air wet-
bulb temperature and the sump water temperature
At what locations in a refrigeration system does the saturation pressure correspond to the saturation
temperature - ✔✔Evaporator and condenser
A split phase motor can use what to energize and de-energize the start winding ? - ✔✔Potential relay,
current relay, and a centrifugal switch
Temperature is an indicaron of the - ✔✔Amount of molecular activity in the material
What can cause high suction pressures - ✔✔Defective compressor valves
