Well my computer room is a screwed up design. Theres no attic space due to vaulted ceilings, the A/C vent faces the window so the heat coming in though the windows kills the cool air. To get the room cool instead of 100+ degrees I installed a window unit. Since now I have a A/C vent that has no use I was thinking to reroute that vent to a server rack. Have the power supply fans and what ever fans on the back of the systems including my mac to suck in and have the front blow out. Also I was thinking about using a air filter to keep the dust out of the server rack.  Also I found a nifty way to make it a high flow by adding a blower fan inside the duct to force the air out faster.

As for the server rack itself I was thinking to build one out of 2X4s, plywood and metal hangers with a nice ebony lacker finish. To seal up the rack I was thinking to use some plastic covering on the inside that is used for house siding or use a ton of silicon. If I had enough money I would build one out of piping and diamond plate.

This project will be set aside until I build my desk/entertainment center.

I was bored and I tried it. I took a extra exhaust duct that goes to a dryer, some cardboard and some duct tape (The metal kind) and connected it to the A/C vent and ran it to my xbox360. I even tossed in a fan for better flow and it cooled the 360 20 degrees.

With out duct 85.4*F
with duct  65.2*F