Re: cooling a terrarium

Wed, 30 Mar 1994 7:24:25 -0500 (EST)

Michael writes:

>No really, a heater works by sending an eletrical current through a resisitor,
>and this (somehow) creates heat (and often light, usually dull red to orange).
>I don't know of any way to reduce ambient heat via electrical resistance.
I agree. An electronics device which CAN cool things is available, and
it obviously is more complicated than a resistor. In my experience
they're called Peltier (pel-tee-AY) devices and they involve a special
semiconductor junction. They usually take the form of a flat plate,
and often they are used in vacuum bell jars as a small platform on
which specimens may be placed. This is convenient when you need to
cool a specimen while it's inside the vacuum bell jar.

Doug, perhaps your father was referring you to Peltier devices. I
don't recommend that you use them since they would be very
expensive and inefficient for your application. Perhaps you could
try a _gentle_ blower fan to help circulate the air. Yes, I know
that you like to keep the humidity very high and that circulating
air may lower it. If the circulation is gentle, though, and if
you have a lot of moisture in the sphagnum that can evaporate,
then the humidity will probably be high enough and the temperature
may be kept at a reasonable level.