unit 45 Flashcards
The typical temperature inside the fresh-food compartment in a domestic refrigerator is
35°F to 40°F.
The operating condition for the single compressor in a household refrigerator is the lowest box temperature, which is typically
0°F
When the air temperature in a domestic freezer is 0°F, the plate-type evaporator temperature may be as low as
212°F.
Typical head pressures should correspond to a condensing temperature ________°F higher than room temperature at design operating conditions.
20°F to 35
Frost accumulates on the evaporators of forced-draft refrigerators because:
they are low-temperature appliances.
When unfrozen product is placed in the freezer compartment of a domestic refrigerator/freezer, the product
will freeze slowly and large ice crystals will likely form.
The compressors used in domestic appliances typically range in size from
1/10 horsepower to 1/3 horsepower.
The flow through the capillary tube metering device is determined by the
inside (bore) diameter and the length of the tubing
A manual defrost system is most likely to be found on what type of system?
An appliance with a natural-draft evaporator
The capillary tube metering device is often fastened where to improve heat exchange and system performance?
suction line
The doors of domestic appliances are typically removed when the appliance is disposed of to prevent
someone from getting trapped inside the appliance.
Condensers in domestic refrigerators and freezers are
air cooled
What is the name given to the heaters that are located around the doors of the appliance to prevent sweating?
Mullion heaters
Which of the following statements is true regarding the interior surfaces of most refrigerators and freezers?
They are made of plastic, are easy to clean, and can become brittle when cold.
The adjustment device used for low atmospheric pressure conditions is called the
altitude thermostatic adjustment control.
The ice-making process in a domestic freezer is typically controlled by
time
Depending on the type of condenser, the condenser saturation temperature for a domestic appliance located in a cool, 65°F room will likely be between
85°F and 95°F
When should gauges be installed on a domestic refrigerator or freezer?
Only when absolutely necessary
A dirty condenser coil on a domestic refrigerator will cause the
appliance’s operating pressures to rise.
Forced-draft evaporators are characterized as being
physically small with large quantities of air moving through them.
The type of compressor typically found on a domestic appliance is
welded, hermetic.
On a domestic appliance with a mechanical draft condenser,
the compressor cycles on and off with the condenser fan motor.
The door switch on a domestic appliance controls the operation of the
evaporator fan motor.
The stand-alone freezer may be configured as either __________ type.
upright or chest
The typical domestic refrigerated box has two outside doors that are configured as __________ styles.
under and over or side-by-side
The evaporators in household refrigerators can be of two types, _________.
natural draft or mechanical draft
T/F
The household refrigerator must maintain two different compartments at two different temperatures with a single compressor.
true
Forced-draft evaporators are normally made of ___________.
aluminum tubing with fins
The fins of an evaporator on a domestic refrigerator are spaced widely apart to___________.
allow frost to build up and not block the airflow
Two common methods for defrosting refrigerator evaporator coils are _______________.
manual and automatic
Ideally, a home freezer operates with a box temperature of about ____°F
0
T/F
A typical domestic ice maker produces between 10 and 12 pounds of ice a day, depending on the model.
false
A refrigerator thermostat is also referred to as a __________.
cold control
