I'm attempting to figure out the power/cooling draw for some old servers that I'd virtualized.
Starting with info in this question, I've taken the 880W the old boxes appeared to be drawing (according to the APC logs), and gotten 2765 BTUs/hr, or 1 ton of cooling every 4.34 hours.
At this point I'm scratching my head as to how to figure the cost for cooling. I'm sure that depends on what I'm using to cool. I'd imagine that ambient temperature counts for something at this point, but I'm not sure if it's significant.
 What I'm missing - I believe - is any idea of what 1 ton of cooling costs. Is that a sensible thing to shoot for, or am I barking up the wrong tree? 
In any case, any pointers on what info to gather next, what to do with it, or what's wrong with the above figuring (if applicable) is most welcome.