I'm trying to build out or new machine room. I'm not sure how to figure how much cooling capacity I need for the number of machines I have. Is there some sort of formula....? number of amps consumed per hour * voltage = X btu? Someting like that?

I currently have about 50 machines that will be in the server room ranging from dual 1GHz PIII to dual 3GHz Xeon. Some 4U, some 2U, most 1U... those and a couple UPSs. The AC unit I have is either a 1.5 ton or 2 ton unit (I don't know what that means as far as BTUs go?). I just want to be sure if that's enough, or if I'll need bigger, or possibly 2 of these. etc.

A "ton of refrigeration" is defined as the cooling power of one short ton (2000 pounds or 907 kilograms) of ice melting in a 24-hour period. This is equal to 12,000 BTU per hour, or 3517 watts.

I found this link which seems like a good starting point.
http://www.periphman.com/computer-ro...lculator.shtml

However, IMO it is just a WAG and you should get professional help designing the room for max efficiency.

P.S. All disclaimers apply

Good info, thanks for that.

I could call a professional, but I'm trying to do this on a budget & through a mistake by the building owner, am getting the AC units for free - so the less outside help required, the better.

That said, I may call a professional.

If anyone else has any ideas, feel free to chime in.

Moved: This thread is more suitable in General and has been moved accordingly to help your thread/question get the exposure it deserves.

Mod note: This is not technically a Linux question, so it's off to General

Hate to tell you this, but I don't think even a 2 ton unit will take care of your situation. We have a small server room with less than 50 servers, but also has UPS's in there and we have 3 - 5 ton units. If one unit can't keep up, then the second unit kicks in, and if two can't keep up, then the third unit kicks in. Our main computer room wich has more than 50 servers and UPS's has a 30 ton unit. On hot days, that unit is doing all it can to keep the room cool. They finally bought a backup unit just in case the main one goes out or it can't keep it cool enough.
As suggested, I would get advice from a couple of professionals. There are a number of things to look at, heat output of all of your machines, future additions to the number of machines you might add, cooling loss out of the server room, etc.
Unfortunately it will cost some bucks, but if you don't do it right, think what will happen if and when your cooling system can't keep up or worse, goes out on the hottest day of the year.
Good luck and I hope it works out for you.