Date: Fri, 12 Jul 2002 21:55:21 -0500
Reply-To: Marshall <mjruskin@SHAW.CA>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Marshall <mjruskin@SHAW.CA>
Subject: Re: anyone bought a Coleman thermoelectric cooler?
Content-type: text/plain; charset=iso-8859-1
I did my graduation thesis from EE on the subject of thermoelectric effects.
These devices are incredibly robust - they are used to power the Pioneer
spacecraft, after all - but they are incredibly inefficient. If I recall,
they are aproximately 3% efficient.
You could get more cooling efficiency by compressing air with an electric
tire inflator, radiating the heat, and then expanding the air through a
venturi! Run it in a cycle. Maybe I'll make one of those!
IMHO, somebody should market a REASONABLY-PRICED, tiny, compression
refridgerator unit. Those can be incredibly efficient - if the hot side is
ventilated well.
Marshall Ruskin
84 Westy
----- Original Message -----
From: "The Bus Depot" <vanagon@BUSDEPOT.COM>
To: <vanagon@GERRY.VANAGON.COM>
Sent: Wednesday, June 12, 2002 06:54 PM
Subject: Re: anyone bought a Coleman thermoelectric cooler?
> > i was in Wally world yesterday and saw they had these 12v Coleman
> > thermoelectric coolers for sale for $69.95.. its like a little
> > frige, but its
> > portable like a cooler..runs off 12v household current or you can use
the
> > cigarette lighter adapter to use it in your car.. it says it can even
make
> > ice cubes! anyone bought one, and what do you think?
>
>
> I haven't used a Coleman brand, but the principle's the same on all of
them.
> They generally lower (or raise, if you reverse the plug) internal
> temperature by around 30 degrees fahrenheit as compared to ambient
> temperature. So theoretically it could make ice on a 62 degree or cooler
> day. I've found that if you run one overnight it's likely to kill your
> starting battery (unless it has an auto low-voltage shut-off), so it's
best
> suited for use while driving (unless you have an aux battery). In
practical
> use, I've found them more useful for keeping items cold that are already
> cold, rather than for cooling warm items. In that context, they do a
great
> job. Also they do great if you throw just a little bit of ice in them as
> well to "help them out" a bit.
>
> - Ron Salmon
> The Bus Depot, Inc.
> (215) 234-VWVW
> www.busdepot.com
>
> _____________________________________________
> Toll-Free for Orders by Part # 1-866-BUS-DEPOT
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