In sci.electronics.repair notbob wrote:
On 2008-03-18, Brawny wrote:

The same process keeps your freezer "frost free".

Not really.

Your freezer remains frost free due to a mechanical process. The defrost
timer completely cuts off the refrigeration unit at regular intervals and
then a fan comes on and blows above-freezing-air from the refrigerator
compartment across the freezer coil vanes which melts the accumulated frost.
This happens for about a 15-30 min period every 12-24 hrs (depending on
make/model). Defroster timer failure is the most common cause of
refrigerator malfunctions. It's an easy fix. Just replace the timer, which
is usually a plug-in module for easy swap out.

nb

At least in my refrigerator there's also a heating element the winds
through the freezer coil.

Jerry