as i read this I realized that the fire brick as not just for fire proofing but also to hold heat and help with recovery.... thanks!This is the heating element that I use. I had a dual element unit from Wally world before this. This unit works much better, I do use a temp controller with it and can control it to plus or minus one degree. If you need help on a controller let me know I can dig up some models that I have found before that are fairly cheap. Either way insulation is going to be a must to make this work well. I would also find a way to use some fire brick or sand to hold the temps in while you open the door