Since when does cool air rise?
Maybe it's a model made for a parallel universe where everything operates opposite this one.
I didn't pay much attention earlier--saw the description, thought it was kind of interesting, and posted without closer study. Now that I have studied it closer, it really doesn't make sense to me, either.
The only thing that does make sense to me is that maybe it was a refrigerator of some sort that lost at least all the external refrigerator parts.