I like the thought you guys are putting into cooling.I do like ideas to help reduce furnace run time and a/c run time as money saved could run more crunchers. Do you have any room to add storage for domestic water heating? this works well for me as I let mine get warm enough to take showers and the tankless sits idle most of the summer. the basement still sees more heat then i wold like from the GPUs and power supplies. If a guy could make an evaporative cooler for outside the house would be useful as well. Maybe some controlling done via a temp controller to dump some heat at a given temp. I currently can run 6 computers on one pump/loop. Keep the ideas and projects coming!