>> The trick is getting it cool enough to operate the systems normally
>> without causing condensation. Likewise you do not want it so dry that
>> static electricity becomes an issue.

My personal server room is always trailing the outdoor temperature by 
about three degrees or less. Of course, there's only one machine in it.

;->

But I do I worry a little when it's 40 C and over 85% humidity.

> I've always found that the trick is to figure out what the heat-load 
> of the room is and figure out what your repair/response time is in the 
> event that the AC shuts down.
>
> ie: one of my machine rooms is surrounded on 5 sides by concrete 
> walls, under ground, and will, if necessary, run just fine with the 
> doors open for a couple of days, especially if I shut down some 
> non-critical systems; in the event of an AC failure.
>
> I run this room fairly warm.  About 22C.
>
> I have another machine room in another facility that will not run by 
> itself even with the doors open and critical systems turned off.  This 
> one I run down to 16C; and if the AC shuts down, I have about 6 hours 
> to respond before the temperature gets high enough to start being a 
> problem.
>
> I know, not scientific or 'procedural'....
>
>