I am just going to go back to the 400W. I think the 600W is just way to much for a DR100. It's just over 3' sq on the footprint. I think i would have to run a really huge fan to move the heat out of that small space quick enough. Not something I want to get into. With the 400W there was maybe at worst 1 to 2 deg increase in tent temp over ambient room temp. That is what I want.

Took the Active Air fan back to the hydro store today and they gave me a full refund. My 4" windtunnel does great sucking through the carbon scrubber, blowing through the cooltube and out of the room. If it ain't broke don't fix it right?