Ventilation, and Air Conditioning (HVAC) |
Building Owners and Managers Association
(BOMA) | Updated Version
Technician "A" says that if the air filter on an air-conditioning system is totally
blocked with dirt, the amperage draw of the evaporator fan motor will go down.
Technician "B" says that if you close down one supply register on a duct system,
the volume of air feeding the other locations will increase slightly. Which of the
following statements is correct?
a. Technician "A" is correct. Technician "B" is correct.
b. Technician "A" is correct. Technician "B" is incorrect.
c. Technician "A" is incorrect. Technician "B" is correct.
d. Technician "A" is incorrect. Technician "B" is incorrect. ---------CORRECT
ANSWER-----------------a. Technician "A" is correct. Technician "B" is correct.
The refrigerant in a refrigeration system changes state in the ____.
a. condenser and compressor
b. compressor and expansion device
c. expansion device and evaporator
d. condenser and evaporator ---------CORRECT ANSWER-----------------d. condenser
and evaporator
,The amount of heat needed to change the temperature of a substance will vary
with the type of substance.
This heat quality is called the ___ of the substance.
a. sensible heat
b. specific heat
c. latent heat
d. relative heat ---------CORRECT ANSWER-----------------b. specific heat
Oil pressure safety controls measure the difference in pressure between the ___.
a. oil pump inlet and discharge pressures
b. oil pump discharge pressure and compressor head pressure
c. oil pump inlet pressure and compressor suction pressure
d. oil pump discharge pressure and compressor crankcase pressure ---------
CORRECT ANSWER-----------------d. oil pump discharge pressure and compressor
crankcase pressure
On a 95°F day, the R-22 refrigerant pressure on the high side should be about
____ psig.
a. 182
b. 108
,c. 297
d. 243 ---------CORRECT ANSWER-----------------d. 243
The pressure in a refrigeration system is changed in the ___.
a. condenser and compressor
b. compressor and expansion device
c. expansion device and evaporator
d. condenser and evaporator ---------CORRECT ANSWER-----------------b. compressor
and expansion device
Positive displacement compressors have crankcase heat to ____.
a. preheat the chilled water for better efficiency
b. prevent refrigerant migration to the compressor
c. preheat the compressor bearings for longer wear
d. minimize condenser subcooling ---------CORRECT ANSWER-----------------b.
prevent refrigerant migration to the compressor
If the power element of a TX valve loses its charge, the ____.
a. coil will flood enough to feed liquid refrigerant out of the coil
, b. valve will get cold enough to create farost on the body of the valve
c. refrigerant flow through the various circuits of the coil will become unbalanced
d. refrigerant flow to the coil will stop ---------CORRECT ANSWER-----------------d.
A normally operating water-cooled condenser is operating with a 10° differential
between water in and water out. If the amount of 85°F water going through the
condenser is reduced, which of the following is a possible temperature of the
water leaving the condenser?
a. 75°F
b. 0°F
c. 95°F
d. 105°F ---------CORRECT ANSWER-----------------d. 105°F
If the resistance against a centrifugal blower is doubled, the cfm output
decreases, and the amperage draw of the motor ___.
a. decreases slightly
b. increases slightly
c. stays the same
d. overheats the motor ---------CORRECT ANSWER-----------------a. decreases slightly