One suggestion that I heard to lessen heat (I think that this came from oldmac) was to remove the heat created by the air pump/s for the buckets. (compressing air creates heat to the stones, and heat to the room) My solution was to run an air supply underground 80?? from a large compressor at a distance and just use a regulator in my flower room. So the heat created locally was no longer an issue.
Since I was never totally impressed with the output (listed 1.75psi) supplied by the air pump I can now up the psi to the airstones to my liking. (with a 6? stone, only about half was creating bubbles) This is a recirculating DWC, but would survive easily on bubbles alone. So being satisfied with the output of the airstones, now I have the option of using the pump or not. (eliminating another source of heat) If I decide on full time circulation, putting it on a timer, or circulation solely for the purpose of ph-ing and/or feeding nutes to the buckets.
I do like options.

Horsemanrocks.