I have two 15g stainless conicals in a fridge and I am building an advanced controller to heat and cool the whole mess. Some details on my blog for those who are curious.
Currently I use a Fermwrap from More Beer to heat the conicals but I feel it works much better for carboys. The fermwrap is hard to get on the conical in such a way to maximize contact and heat transfer. I also want more juice then 40w so I would have to have 4 of these just to cover to conicals.
I have the thermwells, controllers, and cooling figured out, just not an optimal solution for heating.
The question: Can you recommend a good way to heat 15g SS Conical Fermenters?