[Daox]

Good point, I could tell in my test that the fans weren't able to move the heat as quickly as I had hoped for. 2 degree F increase an hour isn't horrible, but there is a lot more heat up there. However, I like the simplicity of the system. Its cheap and easy. I'm quite open to ideas on how to improve it though.

As we move into summer, and heat is no longer needed for the house, DHW heating is a great alternative for using attic heat. I was thinking of running some PEX tubing up there as a simple preheater, and drain it for winter. If you wanted to get fancier, you could add a pump and thermostat to heat up a tank. With my acquisition of the solar hot water panels, it will not be needed. However, I'd love to see someone else do it.