What is the function of the evaporator in the refrigeration system
To act as a heat exchanger between air and refrigerant
Refrigerant in the evaporator
A. changes from vapor to liquid
B. changes from liquid to vapor
C. stays in the vapor state
D. stays in the liquid state
B. changes from liquid to vapor
The sensible heat that is added to a saturated vapor after all of the liquid has boiled away is referred to as
Boiling temperature
What determines the pressure on the low-pressure side of the system
Metering device
A refrigerant system's evaporator typically runs about ___degrees of superheat
8 to 12 degrees Fahrenheit
What does a high evaporator superheat indicate
A starved evaporator
A low evaporator superheat indicates
A. undercharge
B. system restriction
C. overcharge
D. dirt buildup
B. system restriction
Why is a multi-circuit evaporator used
Keeps excessive pressure drop from occurring
Flooded evaporators use a ___ type of expansion device
Float
An evaporator that is not flooded is though of as what type of evaporator
A dry-type evaporator
When an evaporator experiences a heat load increase, the suction pressure
A. remains constant
B. decreases
C. varies up and down
D. increases
D. increases
What is commonly used to defrost the ice from a low temperature evaporator
An electrical heater
A medium temperature refrigeration box operates within what temperature range
A. 28 F to 40 F
B. 40 F to 60 F
C. 0 F to -20 F
D. 0 F to 50 F
A. 28 - 40 degrees Fahrenheit
List seven advantages that an aluminum parallel-flow, plate/fin evaporator has over a standard round, copper-tube plate/fin evaporator
-reduces static pressure throughout coil
-reduces coil depth
-reduced internal volume
-reduced face area of condenspr/evaporator
-30% coil rate and size reduction
-reduction in packing costs
-lowe system costs