Section D - Air Circulation; Principles Of Automatic Defrost Operation; Air Circulation Patterns - Electrolux Side by Side Refrigerators Service Manual

SECTION D - AIR CIRCULATION

AUTOMATIC DEFROST MODELS
Principals Of Automatic Defrost Operation
Automatic defrost refrigerators operate on the principle
that moisture or frost transfers or migrates to the coldest
surfaces (evaporator) in the freezer compartment. For
example, a small amount of water spilled in the freezer
compartment will freeze immediately. However, this ice
in time will evaporate and transfer to the colder surfaces
of the freezer evaporator coil.

Air Circulation Patterns

Automatic defrost models have a single evaporator in the
freezer compartment, and have forced air cooling in the
freezer and refrigerator compartments.
The "fin and tube" aluminum type evaporator is located
on the lower back wall of the freezer compartment. A
circulating fan (suction type) pulls air from the freezer
compartment through the grill in the bottom of the freezer
and from the refrigerator compartment through a duct
located in the separating wall in the bottom rear left hand
corner of the cabinet interior. The air is then drawn up
through the fin and tubes of the evaporator surface. The
cold air is forced into a fan cover and discharged into the
top of the freezer, and out the air discharge under the ice
maker. See Figure D1. If the food compartment control
Figure D1
is calling for cooling, the automatic damper control in the
top of the food compartment will open and allow cold air
to enter the food compartment. If the food compartment
calls for cooling but the fan is not running, the fan will
start as soon as the damper is open, and will continue
to run as long as the food compartment control or the
freezer control calls for cooling.
The air circulating fan operates any time the food
compartment control or the freezer compartment control
calls for cooling. During the defrost period, the compres-
sor and circulating fan do not operate. The automatic
defrost timer or the ADC (Adaptive Defrost Control)
opens the electrical circuit to the fan motor and com-
pressor.
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