OT [sdiy] Peltier Elements

Mon May 12 20:54:33 CEST 2003

Not directly related... but i saw the most ridiculous
product yesterday. It as called eco-fan (or similar iirc)...
it was a fan with an aluminum extruded heatsink... for use inside
a cooking oven. The fins were arranged so that the cool side
of the peltier device was "cooler" than the hot side, it worked
on temperature differential from top to bottom. The Peltier device drove a small electric motor.

Now this might be an alright idea (if it took the full oven temperature, usually 500F max)... and it WOULD make the temperature
insdie the oven less stratified.

But "ECO-fan"... it generates its OWN electricity ??? Bullshit. If you
MOVE that fan, you have to add more energy to the oven, period. And for $70 (USA)... I don't think so. Sometimes the ECO-movement can be so ignorant of the big picture... not to mention that there are a LOT of chemical and metallic compounds I would NOT want in my oven.

H^) harry

>Hey,
>This was looked at by my chamber guru buddy at Agilent
>and I. It is impractical for large chambers, but for a
>small one it it do-able.
>Some points. First, the peltier devices are thin, and
>chamber walls are think, so you'll need a riser (greek
>work meaning 'aluminum block') to get to through the
>wall. Peltiers are rather ineffecient, so for the
>performance you require you may need a hugh power
>supply. Luckily big surplus switchers are cheap.
>Peltiers are soldered together with real low temp
>solder. If you let them get too hot, they will
>unsolder themselves. I once tried to glue a peltier to
>a heat sink using heat-cyred thrermo-conductive epoxy.
>I cleverly thru it into a production oven that said
>150 degrees on it. Sadly it was 150 degrees C. The
>peltier melted and came apart.
>I would like to make my own chamber using a peltier
>for cooling. I was thinking of using an Igloo picnic
>cooler for a cheap chamber. Perhaps a group project??
>Check out these sources for info:
>http://www.peltier-info.com/
>http://www.melcor.com
>Melcor has a nifty calculator for configuring peltiers
>to insulated boxes.
>--Tim
>--- Czech Martin  wrote:
>> Since my thermo chamber has no active cooling, I'm
>> considering
>> peltier elements. They are pretty expensive.
>> I think the problem is that I have to maintain a
>> large temperature
>> difference, i.e. cool the hot side of the element,
>> otherwise
>> it won't cool. This can cause some trouble in the
>> construction
>> and thermal isolation.
>> 
>> Any hints/experiences?
>> 
>> 
>> Martin Czech
>> 
>> CAD/CAE Library Group
>> Micronas GmbH
>> Hans-Bunte-Str 19
>> D 79108 Freiburg
>> Tel.: +49-761-517-2422
>> FAX.: +49-761-517-2258
>> http://www.micronas.com
>>  
>> 
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