I already know my idea is crazy, but please tell me if it also makes any sense at all. My rack is currently in my office, but the noise is beyond what I (and the wife) can bear. I've been given permission to move it all to the garage, but since I'm located in a very sunny and hot part of the world, the garage is pretty hot in the summer (30C+ average, 40-45C peaks). My idea is to seal-off a part of my garage, add a small split AC system (sized to handle about 1.5X - 2.0X the rack's estimated heat load), and move my rack there. I want to set the AC to 28C-30C, to minimize costs while keeping the equipment reasonably happy, but I predict that the AC will have frequent stops and starts, which means the equipment will go through many temp cycles as well. It might be beneficial if I could add a lot of thermal mass to the server chamber, to smooth out these temp cycles. I also want to do it as cheaply as I can. And now to the insane bit - I'm thinking of filling up a lot of that space with large water containers (think 55-gallon drums). They're cheap and should have decent thermal mass (imagine multiple metric tons of water in that room). They're also very bad to have around all my equipment if they ever leak, or god frobid - burst. So - insane, right?