Sorry, please dont angry me for my useless info.
I think that maybe I will appliy it to box-wall. Not only inner air circulated in normally, but 2nd finned-outer-layer will absorbing heats from inner air-temp. Like this

^ hot air
Out | F | In
| ^ |
| ^ |
| ^ |
| ^ |
| ^ |
| ^ |
cool air F> |

Because I'm used aluminium-sheet as I said before. Here where I'm stay have a little problem that min-temp = 27 C , Max-temp = 31.5 C (light off) and when light on is around 35-37 C. This temp level that I've tested it yesterday.
I think eveything will be cool down when i'm make a real growing. Oh, this temp level is measured when temp-probe's 4" far from 250w(hps) bulb and stiil didnt switch vent-sys on and didnt install a hood and 2 side wall yet. So I need to try something else that isnt a/c, If this plant = F, maybe I will use water to cool down a thing.

p.s. sorry for my poor english...and if you stoned too....peace.