Hi, all.
I'm building a Hot Box :-) Now, Now. Settle down there in the back.
This is a wooden box, about the size of a coffin ( say 6 ft x 3 ft by 2 ft ). It's purpose is to hold 4 pairs of skis at a temperature of around 50 -55 deg C for several hours ( to aid wax penetration into the base structure ). It's critical that the temperature does not rise above around 60 degrees ( the p-tex base begins to melt much above that.. ) The temprature may be permitted to cycle reasonably far below the set-point without any harm. I'll just be using the heater's integral stat most likely, not any whizz-bang computerised controll: as I say, I don't mind a reasonable hysteresis, so long as I can limit the temperature at the peak of the cycle.
This will be used in my garage ( part of the house, not warm, but not cold either. )
The general advice is to use an oil-filled 'baseboard heater', along with a circulating fan in the cabinet. The general consensus is that the oil-filled units produce temperature fluctuation cycles which are more damped than using a straight fan heater. This helps avoid big temperature 'spikes' when the heater cycles on.
The question I have is: what kind of wattage of heater would perform reasonably in this role? It obviously depends on the heat loss from the box. Assume say an un-insulated 18mm plywood box in a domestic garage. Since we're only going up to 55 degrees, I'm hoping the temperature gradient from inside to outside is small enough that the heat loss will be low enough to permit the use of a fairly low wattage heater.
I suspect the answer is suck-it-and-see :-)
Just looked at my kitchen fan oven. It's 2.5KW, and can ramp the oven up to over 250 deg C. It's insulated, and smaller, but the heat loss at that temp will be fairly high.
I'm thinking of trying something in the range of