The heat channel looks like a stroke of brilliance. 
Please report on how it works on the ice.
I can see one on mine blowing hot air over the folding filleting table on the outside wall.
You sir... are the first to associate me with brilliance. I don't have a ton of ice house experience, but the ones I have been in were freezing cold at the feet and Indiana Jones Arc of the Covenant hot when you stood up. I had a fan and a few boards... I ran a smoke test, it sucked it in as planned, and there is air coming out the bottom. Noise is minimal.
