If this works this would be a great option for me. I have steel conicals but in an apartment thats really too small to set up one of those son of fermentation chambers (nor the tools or desire to build).
I use peltier junctions to cool my fermentation chamber, so it certainly can work. This seems like an interesting possibility, but I'm skeptical that this would work without very significant insulation.
This past winter I placed a heating pad under my fermenter to regulate the temp. It kept my fermenter at 68*F. It also doesnt have a timer so it could go as long as I wanted. I dont know about the cooling side but it seems sweet.