Koz wrote:



George wrote:

Peltier devices (also known as TEC, thermo-electric coolers, and TEG,
thermo-electric generators)
are solid state devices that transfer heat (or cold) from one side of the
device to the other. Or, they'll
produce a voltage in response to a temperature differential. The normal
temp differential from the
"hot" side to the "cold" side of the device is about 50 degrees Celsius (a
LOT more than any pet would
like), BUT you still need to move the heat off the "hot" side if you're
trying to cool (think heat sink and
fan) AND circulate the air on the "cold" side. It is really made for
cooling surfaces, I don't know how
successful you'll be in cooling air. Why don't you report back if you
pursue this?

George

Some of the 12v coolers for cars use em for air cooling. Very slow to
actually cool anything but work ok at keeping cold something that's
already cold. Probably just undersized when used in this application
due to cost.

Anyway...because they work based on creating a temperature differential,
isn't there an application where the are stacked to reach VERY cold
temps? You'd have to pump one hell of a lot of heat out of the final
stage but it might be interesting to see just how cold one could get the
cold side.

Koz
There are small cryo-coolers based on stacks of Peltiers that are used
down to about 100 kelvin. They're like 5 - 7 stages; each stage needs
to have 50% to 100% more area than the last so they look like pagoda
roofs. Around 100K sterling coolers start to gain ground for that sort
of thing.

--

Tim Wescott
Wescott Design Services
http://www.wescottdesign.com