i found one that is made for harddrive, that has two little fan(bigger than 80mm each), blowing from the botton or on top depends on where u want.
I touch my drives on the morning, that nite they didn't to anything, they just sit there overnite... but i do feel it is quite hot. however I can still put many hand on it(not burning)but isn't it should be warm or even lower temp because it didn't anything overnite..
wow, if i try to BT at nite, it gets even hotter.