Re: cooling a terrarium
Wed, 30 Mar 1994 10:18:15 -0500 (EST)

Peltier effect devices are used in the small "solid-state" coolers
designed to run on a car cigarette lighter or other 12V source. They are
not real cheap (I think $30-50) for a smal one) and not capable of pumping
alot of heat. I belive the company that makes the thermoelectric heatpump
modules is called Melcor. I don't have the address but a local librarian can
find it in the Dunn and Bradstreet (?) business index (I think). These
devices consume alot of current and may need special electronics to get
optimal cooling.
We tried using a dorm fridge to cool incubator/shaker. With no success.
The heat generathed by the shaker motor and the heat absorbed by the lines
carrying coolant (H2O + antifreeze) exceeded the capacity of the fridge. It
would probably work with a large enough fridge and lots of insulation. Try
to isolate all heat sources (lamps and ballasts from the terrarium) (blowers
and such to remove lamp heat). Would the compact fluorescents be a better light
source since they run cooler?
I don't know about evaporative cooling in a terrarium but a homebuilt pad
works great in my greenhouse. The 1st attempt employed the resuable
furnace filters available at most stores (appears to be blue dyed and
bonded hog hair or some such stuff). A 2 x 4 foot pad wetted by a
continuous circulation pump produced about 5-10 F cooling. A new
version using Kool-cel pads (Munters-available from VJ GROWERS and other
fine supply houses) produced a steady 10 F drop in temperature. Specs:
2 x 4 pad, 10x12 greenhouse, 1650 cfm attic fan. The entire thing was
made from PVC pipe and vinyl gutter on a 2x4 PT wood frame.

Hope this is of some use,