BOMA – HVAC CORRECT 100%
Two basic categories of chillers are the - ANSWER compression cycle and absorption
The five requirements for comfort are proper temperature, humidity, filtration, and ventilation -
ANSWER circulation
The primary function of an expansion device is to - ANSWER produce a reduction in the pressure on the
liquid refrigerant, regulate the flow of refrigerant into the evaporator, lower the boiling point of the
refrigerant far enough below the temperature of the load to get the needed heat transfer rate
The wet-bulb depression is - ANSWER the difference between the dry-bulb and wet-bulb temperatures
The dew-point temperature is the - ANSWER 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? - ANSWER 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°F? - ANSWER 9°F
On an R-11 or R-123 system, the refrigerant removal process normally starts with the removal of -
ANSWER liquid refrigerant
The condenser in a refrigeration system - ANSWER de-superheats the vapor from the compressor,
condenses the vapor from the compressor, sub-cools the liquid refrigerant before it leaves the condenser
The human body gives off heat by which of the following? - ANSWER convection, radiation, and
conduction
, If the temperature remains constant and the volume that a gas occupies increases, the pressure will -
ANSWER decrease
Transformers are rated using - ANSWER volt-amperes
Measuring velocity pressure in a duct indicates the - ANSWER speed at which the air is moving
A solid material exerts a pressure or force - ANSWER downward only
Pure water boils at a temperature of 212°F at which of the following standard conditions? - ANSWER
14.967 psi
Which of the following would allow a system to operate more efficiently? - ANSWER condenser that had
refrigerant leaving with 15° of subcooling
One watt of electrical energy is equal to - ANSWER 3.413 Btu
Rotary compressors are used primarily in - ANSWER domestic refrigerators
The water circuit in shell and coil and coil-type tube-in-a-tube condensers must be cleaned - ANSWER
chemically
When a water regulating valve is used to control the head pressure of a water-cooled system, the valve's
spring is acting against which pressure to modulate the water flow? - ANSWER head pressure of the
system
The standard atmospheric pressure at sea level is - ANSWER 29.92" Hg
Two basic categories of chillers are the - ANSWER compression cycle and absorption
The five requirements for comfort are proper temperature, humidity, filtration, and ventilation -
ANSWER circulation
The primary function of an expansion device is to - ANSWER produce a reduction in the pressure on the
liquid refrigerant, regulate the flow of refrigerant into the evaporator, lower the boiling point of the
refrigerant far enough below the temperature of the load to get the needed heat transfer rate
The wet-bulb depression is - ANSWER the difference between the dry-bulb and wet-bulb temperatures
The dew-point temperature is the - ANSWER 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? - ANSWER 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°F? - ANSWER 9°F
On an R-11 or R-123 system, the refrigerant removal process normally starts with the removal of -
ANSWER liquid refrigerant
The condenser in a refrigeration system - ANSWER de-superheats the vapor from the compressor,
condenses the vapor from the compressor, sub-cools the liquid refrigerant before it leaves the condenser
The human body gives off heat by which of the following? - ANSWER convection, radiation, and
conduction
, If the temperature remains constant and the volume that a gas occupies increases, the pressure will -
ANSWER decrease
Transformers are rated using - ANSWER volt-amperes
Measuring velocity pressure in a duct indicates the - ANSWER speed at which the air is moving
A solid material exerts a pressure or force - ANSWER downward only
Pure water boils at a temperature of 212°F at which of the following standard conditions? - ANSWER
14.967 psi
Which of the following would allow a system to operate more efficiently? - ANSWER condenser that had
refrigerant leaving with 15° of subcooling
One watt of electrical energy is equal to - ANSWER 3.413 Btu
Rotary compressors are used primarily in - ANSWER domestic refrigerators
The water circuit in shell and coil and coil-type tube-in-a-tube condensers must be cleaned - ANSWER
chemically
When a water regulating valve is used to control the head pressure of a water-cooled system, the valve's
spring is acting against which pressure to modulate the water flow? - ANSWER head pressure of the
system
The standard atmospheric pressure at sea level is - ANSWER 29.92" Hg
