Cooling for a small server room

I would use a portable air conditioning unit that consumed it's own condensation and kept the room at 50% relative humidity. Some people argue that dew point is a better metric, but I haven't looked into it deeply enough and am willing to be corrected. Some A/C units will push their condensation through a hose that snakes through the A/C unit's exhaust hose and thus gets evaporated into the hot, dry output air and into the plenum and exhaust system. You could also get an A/C unit that has condensation tanks and just remember to empty them every day. Annoying, yes. But sometimes an admins gotta do what an admins gotta do.

Either way, you must have exhaust. You can run a duct hose from the A/C's output into the plenum space or near the outtake. That might not be sufficient though. IMO, A/C output is your biggest problem here. Might be nice in winter, you can barter with different departments on which cubicle space the exhaust hose will run to each week. :)

Plenty of companies make portable cooling units made for permanent usage in server rooms. Some companies include:

• Atlas
• Topaz
• Movin Cool (I think Atlas bought Movin' Cool, or the other way around, or something else. There seems to be some relationship between the two companies that I haven't determined yet)

I blogged about portable A/C units a little while back on my old blog here: http://thenonapeptide.blogspot.com/2009/12/list-of-portable-cooling-units.html

You really don't want to be stuffing about with this sort of thing or relying on guesswork. Just for starters I suggest you get that ceiling finished off and fitted with an exhaust fan or two.

For scaling the A/C I suggest talking to the A/C people, who know a lot more about this stuff than we do. Tell them the load you're currently running, after adding a bit more than than the maximum you can reasonably expect it to ever be. Don't forget to mention that it needs be be running 24/7. I actually prefer to have multiple units, each of which can handle the normal load, even if it's straining to do so. That way you can more easily deal with a failed unit.

In simple terms, the electricity your gear consumes exits as heat. Work out, or measure if you have the gear, how much you're using. If in doubt get an electrician to measure it for you. It's a small investment that can save you a lot of money later.

I've used one of the portable units in the past, and during peak temperatures, we were able to keep things about 20 degrees cooler. We'd also put some insulation on top of the drop ceilings, which seemed to help quite a bit. On a side note, you're lucky for the lack of windows - this "server room" had an entire wall of windows, which we went to great lengths to block off, as it was a huge source of additional heat.