2027 LATEST VERSION QUESTIONS AND VERIFIED
CORRECT ANSWERS JUST RELEASED
An example of a poor conductor of heat is? (pg. 1-3)
A) Aluminum Tubing
B) Schedule 40 Steel Pipe
C) Wood
D) Water - answer>>>C) Wood
What causes liquid circulation through a gravity flooded evaporator? (pg. 7-4)
A) The difference in refrigerant densities between the surge drum and the evaporator
heat transfer surfaces
B) A pump
C) The higher pressure in the surge drum forces the refrigerant downward and into the
evaporator
D) Superheat - answer>>>A) The difference in refrigerant densities between the surge
drum and the evaporator heat transfer surfaces
What happens to the un-evaporated liquid that circulates through a gravity flooded
evaporator? (pg. 7-2)
A) It returns to the evaporator through the defrost bypass line
B) The liquid is pumped back to the receiver
C) The receiver is isolated and the liquid is returned to the evaporator feed line
D) The liquid flows to the surge drum and is returned to the evaporator - answer>>>D)
The liquid flows to the surge drum and is returned to the evaporator
A gravity flooded shell and tube product chiller? (pg. 7-6)
A) Usually has refrigerant in the shell
B) Usually has refrigerant in the tubes
C) Has refrigerant in the shell and the tubes
D) Is more efficient with the refrigerant in the tubes - answer>>>A) Usually has
refrigerant in the shell
As the load decreases on a gravity flooded evaporator, the amount of liquid in the heat
exchange circuits? (pg. 7-10)
A) Does not change
B) Increases
C) Decreases
D) Decreases by one-half - answer>>>B) Increases
,Having a DX evaporator and a gravity flooded evaporator of the same size and surface
area, why is capacity better for a gravity flooded evaporator than in a dry expansion
evaporator? (pg. 7-1/2)
A) Gravity flooded evaporators are made from larger tubing than dry expansion
evaporators
B) Gravity flooded evaporators have greater wetted refrigerant surfaces
C) Gravity flooded evaporators have more fins per inch
D) Gravity flooded evaporators operate at lower temperatures - answer>>>B) Gravity
flooded evaporators have greater wetted refrigerant surfaces
What are two main components used in a gravity flooded evaporator design not
employed in a typical dry expansion evaporator system? (pg. 7-2)
A) Two-speed fans and water defrost
B) A thermostatic expansion valve and a low temp cut-out
C) A surge vessel and liquid level control device
D) Fan shutters and 24 volt control - answer>>>C) A surge vessel and liquid level control
device
The vapor leaving the surge drum on a gravity flooded evaporator operating at design
conditions is? (pg. 7-2)
A) Called "wet suction"
B) Superheated
C) Subcooled
D) Saturated - answer>>>D) Saturated
Where should oil be drained from in a halocarbon gravity flooded system?
(pg. 7-7)
A) The bottom of the receiver
B) The bottom of the low-pressure accumulator
C) The return line from the evaporator to the surge drum
D) Oil is 'skimmed' off the surface of the liquid - answer>>>D) Oil is 'skimmed' off the
surface of the liquid
What controls the recirculation ratio on a gravity flooded evaporator?
(pg. 7-4)
A) The setting of the hand expansion valve
B) The boiling action within the evaporator
C) The back pressure regulator
D) Gravity flooded evaporators do not have recirculation ratios - answer>>>B) The boiling
action within the evaporator
,What is the maximum recirculation ratio for a gravity flooded evaporator reference in the
text? (pg. 7-4)
A) 3:1
B) 4:1
C) 16:1
D) Gravity flooded evaporators do not have recirculation ratios - answer>>>C) 16:1
What happens to flash gas in a gravity flooded evaporator system? (pg. 7-4)
A) It goes directly to the evaporator
B) It goes through the surge drum to the compressor
C) There is no flash gas in a gravity flooded evaporator system
D) It is used to power the pumper drum - answer>>>B) It goes through the surge drum to
the compressor
In regard to oil accumulation in evaporators? (pg. 7-7)
A) Oil should be removed because it interferes with the ability of the refrigerant to
exchange heat at the surface of the evaporator tube
B) Oil is desirable in the evaporator because it has a better heat transfer co-efficient
C) Oil accumulation in the evaporator improves defrost characteristics
D) Oil normally does not accumulate in evaporators - answer>>>A) Oil should be
removed because it interferes with the ability of the refrigerant to exchange heat at the
surface of the evaporator tube
How much superheat is found at the outlet of a surge drum of a properly operating
gravity flooded system? (pg. 7-2)
A) 5°F per pound of refrigerant
B) 5°C per pound of refrigerant
C) 10°F
D) There is generally no superheat - answer>>>D) There is generally no superheat
Which evaporator type would see a greater liquid refrigerant flow rate for the same
refrigeration capacity? (pg. 7-1)
A) Dry expansion under heavy heat load
B) Gravity flooded under heavy heat load
C) Dry expansion under light heat load
D) Gravity flooded under light heat load - answer>>>B) Gravity flooded under heavy heat
load
Oil return from an R-22 system low temperature vessel is? (pg. 7-7)
A) Easy because oil vaporizes
, B) Drained from the bottom of the unit
C) Recovered by special features in the low side vessels
D) Recovered by gravity flow - answer>>>C) Recovered by special features in the low side
vessels
What would be a service problem if Ammonia type intercoolers are used in an R-22
system? (pg. 7-7)
A) Oil must be drained from the bottom on a regular basis
B) Oil might accumulate in the intercooler since there are no skimmer ports in an
Ammonia intercooler
C) Oil will return to the compressor with no problem
D) There will be no service problems if they are the same pressure rating - answer>>>B)
Oil might accumulate in the intercooler since there are no skimmer ports in an Ammonia
intercooler
Adjusting flow in a two-pipe secondary coolant system may be difficult because? (pg. 8-9)
A) Brine solution has a high specific gravity
B) Load variation
C) Evaporator size variation
D) Short circuiting - answer>>>D) Short circuiting
The three pipe brine system is considered balanced because? (pg. 8-9)
A) The evaporators are the same size
B) Resistance to flow is fairly equal in all circuits
C) The pipe size is the same
D) It has restricting valves - answer>>>B) Resistance to flow is fairly equal in all circuits
How is the change of state affected when a quantity of salt is added to water that results
in a 10% solution? (pg. 8-3)
A) The freezing temperature is lowered
B) The specific gravity is decreased
C) The freezing temperature is increased
D) There is no effect - answer>>>A) The freezing temperature is lowered
All glycol-based solutions can be classified as? (pg. 8-6)
A) Secondary coolants
B) Non-toxic
C) Corrosive
D) Brines - answer>>>A) Secondary coolants
What is the approximate freeze point of a 20% solution of calcium chloride? (pg. 8-4)