A freind of mine uses an old refrigerator with an air conditioner
thermostat replacing the door light switch set to 105deg.F.it holds 2
five gal buckets easily.There are also plans for a heater box at barry
birky"s page.uses a light bulb for heat source. bee careful,a 100w bulb
wired to stay on constantly will melt the plastic liner in the
refrigerator.