I thought an attic fan was a fan in your attic that looks like a huge vent in your ceiling....:dunno: Thats what they call those things here anyway!

As for the hot garage problem, my dad has a loft over his garage and used to have the same problem. He was recently getting all the wood replaced on his house because it rotted (quality builder ) and he found that the vent on the overhang of the roof that should have been a 2x6 opening was about a 3" narrow diamond cut out....does that make sense? Anyway, they cut larger vent holes which allowed more air to get upstairs and helped to solve his heat problem. To cool your garage, I would say get a ceiling fan or two to keep the hot air pushed downwards :dunno: