Correct Answers
Two basic categories of chillers are the _____.
✓ ~~~ Compression cycle and absorption
The five requirements for comfort are proper temperature, humidity, filtration, _____.
✓ ~~~ Circulation
The primary function of an expansion device is to _____.
✓ ~~~ All of the above (produce a reduction in the pressure on the liquid refrigerant,
regulate the flow of refrigerant into the evaporator and 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 _____.
✓ ~~~ The difference between the dry-bulb and wet-bulb temperatures.
The dew-point temperature is the _____.
✓ ~~~ Temperature when the moisture begins to condense out of the air.
How many Btu are required to change one pound of ice at 20°F to steam at 220°F
✓ ~~~ 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
, ✓ ~~~ 9
On an R-11 or R-123 system, the refrigerant removal process normally starts with
the removal of _____.
✓ ~~~ Liquid refrigerant
The condenser in a refrigeration system _____.
✓ ~~~ All of the above (desuperheats the vapor from the compressor, condenses the
vapor from the compressor and subcools the liquid refrigerant before it leaves the
condenser)
The human body gives off heat by which of the following?
✓ ~~~ All of the above (convection, radiation and conduction)
If the temperature remains constant and the volume that a gas occupies increases,
the pressure will _____.
✓ ~~~ decrease
Transformers are rated using _____.
✓ ~~~ Volt-amperes
Measuring velocity pressure in a duct indicates the _____.
✓ ~~~ Speed at which the air is moving
A solid material exerts a pressure or force _____.