Quote Originally Posted by WingedWolfPsion View Post
I'd go with plywood, and it doesn't have to be very thick--you're going to line it with heavy insulation foam board, right?

I'm experimenting with making one out of just foam board, with 2X3s for a frame.
Something like this? I used 2x2's for the frame, so the 2" insulation would fit flush inside the frame. It works pretty good.


As to the fans, you want them on all the time. If you plug them into the thermostat, not only will you likely burn them out pretty quickly, but they won't be circulating the air to keep an even temperature inside.