Posted by j.soar.aero on May 19, 2008, 1:30 pm
I run a small room air conditioner in my bed room just on hot
evenings. An idea I had is to use PV panels with a small battery and
inverter to power a small chest type freezer during the day just when
the sun shines. The freezer would be full of water to freeze. Then in
the late evenings I would open the lid and blow warm room air over the
ice for cooling the room.
This is not likely a new idea and I have not looked into it very much
yet. I know it would not likely ever pay for itself, but it might be
fun to try, and might reduce my carbon foot-print too. Any thoughts?
JRB in central Illinois
Posted by nicksanspam on May 19, 2008, 4:35 pm
Oops. Wrong newsgroup.
Posted by Kitep on May 20, 2008, 1:26 am
Sounds like a plan. Good luck.
Posted by Mauried on May 20, 2008, 2:12 am
On Mon, 19 May 2008 21:26:07 -0400, "Kitep"
It will work , but its a very expensive way to achiev what you want.
Firstly the compressors in fridges / freezers need a sine wave input
to run properly.
They will overheat on square wave or modified square wave which is
what most small inverters produce.
The next problem is the start current which can be anywhere from 3
times to 8 times the run current.
This means a pretty big sine wave inverter, and a similar big battery.
The last point is that fridfge / freezer compressors arnt designed to
run continuously so if you overload it by filling it up with water the
compresser thermal cutout is likley to operate many times during the
A small 24V truck air conditioner running straight off the battery
powered by the solar pahels would make more sense.
Posted by Jeff on May 21, 2008, 6:46 pm
And, of course, that the net effect would be warming the room, not
cooling it. Remember that all that heat that is being pumped out of the
freezer is being pumped into the room, not exhausted outdoors as an AC
It's a thoroughly dumb idea. Everyone has dumb ideas though... Some
even have 29% approval ratings.
This makes more sense, relative to the freezer idea, but only relative
to getting cheap and plentiful solar PV.
Consider solar desiccant cooling, there's other ideas coming down the
pike but they require emerging (though very old) technologies.