It doesn't make any noise, only a 120v heating element is turned on, and
cool down takes hours.
But, you can usually feel the aluminum heat exchanger getting cold
within a half hour.  These units have no moving parts except for a fan
some say exists or is added, I am not sure which.  I am not sure mine
even has one, it has never come on.

For more than you probably want to know about adiabatic cycle
refrigerators see the technical section here: http://www.rvmobile.com/
The design discussed is a bit different from ours, but the principles
are the same.

When I first got my '84 used in '86, it would not light.  I removed it
and took it too a repair shop. All they did was reposition the ignitor
sparker closer to the gas orifice and it has worked perfectly for 15
years now, fan or no fan.
--
Stuart MacMillan
Manager, Case Program
800-909-8244 ext 208

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