I built an i7 920 based computer around the middle of last year, after having spent quite a while pining over how I would construct it. I had looked at building two separate systems, one as a HTPC/media server and another that would serve as a work computer. After looking at the price of building two separate computers I ended up deciding I could easily combine both roles into a single computer, and use money saved by avoding duplications (such as PSUs, mobos etc) into purchasing a single computer that did more than the two combined.
We have an entertainment cabinet sized for an old CRT TV, so with our 32" LCD HDTV I decided it would be possible to place the computer behind, but after a few months I decided the airflow was not optimal, resulting in a computer that was running a bit hot and a bit noisy for our liking (never mind the fact the lounge room gets pretty hot with the fire on).
Luckily, our lounge room is directly above our garage with 1970s wooden floors separating the two and a loft hanging from the garage ceiling. I drilled a hole up through the floor flush with the wall (drilling up into the wall cavity wasn't an option and the entertainment unit hides it perfectly) and then pushed up an HDMI cable and USB extender (for a wireless keyboard and mouse).
The system works perfectly for my needs, although I must admit playing games on a TV isn't as easy as I expected it would, but the picture looks amazing (even with just a Radeon HD 4770). But having done that I found I simply had too much time on my hands... So I decided on a new project - water cooling!
Now I could have gone for a relatively simple build and grabbed an all in one kit, but I decided I'd try and do something a little more creative... A few months later and I'm one marginally leaky connector away from what what I would proudly say is an insane cooling system.
Inside the computer I have the only actually computer cooling part of the entire rig: a Zalman water block, because its on top of what was worth a couple of thousand dollars, I decided I'd go legit there. But that's where standard finishes!
The water is pushed into the waterblock by an aquaflow pond pump, immersed in a resevoir furnished from a Klip it container. Funny story about the pond pump, I got it from the switched on gardener not long before it got visited by the boys in blue.
After having passed through a reducer as the waterblock is 10mm and the pump is 19mm. Once it's been through the water block, it is then passes through another reducer that brings it back up to 19mm for it's trip to the radiator.... 5 metres away.
The radiator is actually a Ford Falcon heater core, which forms the back end of the cooling unit: a mdf box that contains the radiator at one end and 30cm desk fan at the other. It is about 30cmx 30cm x30xm. The cooling unit has enough space for another heater core, should I ever decide to put another one in, and the fan pulls the air through the heater core and vents it out under the house.
As I said, I'm a single slightly drippy connector away from putting the system into serious water tightness testing and then tests to see how well it cools the CPU. As far as powering the system: I'm going to put the pump on my UPS and depending on how well the radiator cools the system without the fan operating, I intend to put the fan on a non UPS circuit. In any event there is roughly 6l of water in it, and about 20 minutes of run time on batteries, so the temperatures shouldn't rise that much in that time period.
Anyway, I thought I'd share my project with the team here - I have photos if anyone would like to see them: