I have designed a Rack Cabinet for my servers. Unlike common installations I have designed the cabinet so that it will not need Air Conditioning. It is located in a cool area with a large thermal mass that is at room temperature, and will be rather hard to heat up.
The cabinet is designed to allow for natural seperation of air. Most computer racks pull cold air from the front and push it to the back. So I have designed the air to come into the rack from the front, right at the bottom. The exhaust air is at the back at the top. This means that hot air will rise helping cooling. I have baffles front and back to assist with the segregation, and I have ensured that the rack is full. Not with equipment, but with panels.
This seems to be working really well, although I have just been looking at the rack now that things are starting to warm up. I have had some heat building up at the top of the front of the rack. Opening up one of the vents helped this, and significantly reduced the temperature of the rack metal. At the back I only have two 4″x6″ exhaust vents, and these are not connected to anything but natural ventelation. I have just found that this is not providing the cooling I need – so I have put a 4″ fan on one of the outlets. I will see how that goes over the next few hours. I expect that this will help a lot.
I have included insulation inside the cabinet for noise, but this is insulating from heat too. I might need to monitor things over Summer, but given the thermal mass I doubt that I will have too many issues. Worst case I will wheel the rack into an air conditioned area.