AC or DC refrigeration?

[Leehamrick]

Hi,
Just a question about refrigeration,,
Would I be better off with a DC unit or an AC and a small inverter?
I will be using solar power and I have been told that DC appliances really suck up the juice
is this true? I'm looking at about 3.5 cubic feet frigs

[Sunking]

I'm looking at about 3.5 cubic inch frigs

That is the size of an ice cube.

If you are talking about off-grid battery systems the most efficient fridge and freezers are DC 24 volt like those made by Sundanzer. They make a 4.7 cubic feet dorm style refrigerator but be prepared for sticker shock with a price tag of $1150. However that is money well spent because it will save you big bucks on solar and battery equipment. Stay away from 12 volt unless this is a RV.

[mapmaker]

Also take a look at Steca's offerings:

http://www.steca.com/index.php?PF-166---PF-240--Solar-refrigerator-freezer

--mapmaker

[Mike90250]

So you really have to evaluate your needs and $$. Regardless, it won't be cheap. If you are moving beyond a 25# block of ice for a weekend, you may find you want some 120V appliances.

Simple thermoelectric coolers can give you up to a 40F reduction from outside temp, simple, rugged, no moving parts, but very low efficiency and will need a huge battery bank and PV array to run when dark. Or they can wire right up to a PV panel and just "work" daytimes.

A compressor fridge, can have a DC or AC motor. AC motors need AC power from a Pure sine inverter, and have a large starting surge requirement. But the fridge is cheap !