HVAC Pretest BOMA|| 100 QUESTIONS||
CORRECT ANSWERS|| RATED A)
Two basic categories of chillers are the ___.
a. Compression cycle and absorption
b. purge and absorption
c. absorption and lithium bromide
d. purge and lithium bromide - ANSWER a. Compression cycle and absorption
The five requirements for comfort are proper temperature, humidity, filtration, _____, and ventilation.
a. circulation
b. velocity
c. sq.ft.
d. none of the above - ANSWER a. circulation
The primary function of an expansion device is to ____.
a. produce a reduction in the pressure on the liquid refrigerant
b. regulate the flow of refrigerant into the evaporator
c. lower the boiling point of the refrigerant far enough below the temperature of the load to get the
needed heat transfer rate
d. all of the above - ANSWER d. all of the above
The wet-bulb depression is ____.
a. the difference between the dry-bulb and wet-bulb temperatures
, b. the same as the wet-bulb temperatures
c. the same as the dry-bulb temperatures
d. when the air is saturated with moisture - ANSWER a. the difference between the dry-bulb and wet-
bulb temperatures
The dew-point temperature is the ___.
a. temperature when the air is saturated with moisture
b. temperature when the moisture begins to condense out of the air
c. difference between the dry-bulb and wet-bulb temperatures
d. temperature of the air at 50% relative humidity - ANSWER b. temperature when the moisture begins
to condense out of the air
How many Btus are required to change one pound of ice at 20°F to steam at 220°F?
a. 1,304 Btu/h
b. 2,608 Btu/h
c. 6,520 Btu/h
d. 3,912 Btu/h - ANSWER a. 1,304 Btu/h
If an R-12 refrigeration system is operating with a 25.4 psig suction pressure, what is the evaporator
superheat if the evaporator outlet temperature is 34 degrees F.
a. 9°F
b. 59°F
c. 34°F
d. 25°F - ANSWER a. 9°F
On an R-11 or R-123 system, the refrigerant removal process normally starts with the removal of ____.
, a. water
b. liquid refrigerant
c. vapor refrigerant
d. oil - ANSWER b. liquid refrigerant
The condenser in a refrigeration system ___.
a. desuperheats the vapor from the compressor
b. condenses the vapor from the compressor
c. subcools the liquid refrigerant before it leaves the condenser
d. all of the above - ANSWER d. all of the above
The human body gives off heat by which of the following?
a. convection
b. radiation
c. conduction
d. all of the above - ANSWER d. all of the above
If the temperature remains constant and the volume that a gas occupies increases, the pressure will
____.
a. decrease
b. increase
c. remain the same
d. cannot be determined from the information given. - ANSWER a. decrease
Transformers are rated using ___.
CORRECT ANSWERS|| RATED A)
Two basic categories of chillers are the ___.
a. Compression cycle and absorption
b. purge and absorption
c. absorption and lithium bromide
d. purge and lithium bromide - ANSWER a. Compression cycle and absorption
The five requirements for comfort are proper temperature, humidity, filtration, _____, and ventilation.
a. circulation
b. velocity
c. sq.ft.
d. none of the above - ANSWER a. circulation
The primary function of an expansion device is to ____.
a. produce a reduction in the pressure on the liquid refrigerant
b. regulate the flow of refrigerant into the evaporator
c. lower the boiling point of the refrigerant far enough below the temperature of the load to get the
needed heat transfer rate
d. all of the above - ANSWER d. all of the above
The wet-bulb depression is ____.
a. the difference between the dry-bulb and wet-bulb temperatures
, b. the same as the wet-bulb temperatures
c. the same as the dry-bulb temperatures
d. when the air is saturated with moisture - ANSWER a. the difference between the dry-bulb and wet-
bulb temperatures
The dew-point temperature is the ___.
a. temperature when the air is saturated with moisture
b. temperature when the moisture begins to condense out of the air
c. difference between the dry-bulb and wet-bulb temperatures
d. temperature of the air at 50% relative humidity - ANSWER b. temperature when the moisture begins
to condense out of the air
How many Btus are required to change one pound of ice at 20°F to steam at 220°F?
a. 1,304 Btu/h
b. 2,608 Btu/h
c. 6,520 Btu/h
d. 3,912 Btu/h - ANSWER a. 1,304 Btu/h
If an R-12 refrigeration system is operating with a 25.4 psig suction pressure, what is the evaporator
superheat if the evaporator outlet temperature is 34 degrees F.
a. 9°F
b. 59°F
c. 34°F
d. 25°F - ANSWER a. 9°F
On an R-11 or R-123 system, the refrigerant removal process normally starts with the removal of ____.
, a. water
b. liquid refrigerant
c. vapor refrigerant
d. oil - ANSWER b. liquid refrigerant
The condenser in a refrigeration system ___.
a. desuperheats the vapor from the compressor
b. condenses the vapor from the compressor
c. subcools the liquid refrigerant before it leaves the condenser
d. all of the above - ANSWER d. all of the above
The human body gives off heat by which of the following?
a. convection
b. radiation
c. conduction
d. all of the above - ANSWER d. all of the above
If the temperature remains constant and the volume that a gas occupies increases, the pressure will
____.
a. decrease
b. increase
c. remain the same
d. cannot be determined from the information given. - ANSWER a. decrease
Transformers are rated using ___.
