Our Server room is located in the middle of our building and has no access to a window or outside ventilation. I had a quote done by a local heating/air conditioning company to install a room specific temperature control module, but this was going to be quite an expensive addition.
We are a relatively small company (roughly 60 users) and our server room consists of 2 servers, 5 switches, 1 firewall, 2 Modems and a few UPS's. During the nights and weekends, the rooms temperature often peaks between 85-89 degrees and I've finally received some management support to do something about it.
The best (most cost effective) solution I've been able to find is to buy a portable A/C unit (8000-12000 BTU) and vent the unit (via the exhaust hose) into the drop ceiling plenum area. Our Server room is very small (roughly 8x5) and I am assuming the A/C unit will not need to work very hard to keep the room at a constant temperature.
My concern is with regards to venting the unit into the open drop ceiling (the plenum runs the entire area of the office). Will venting from the small server room into this area have a significant heating effect on the rest of the office? Also, does the A/C exhaust contain any moisture that will cause mold in the long term?
Let me know if you've had a similar issue and/or what solutions might be plausible.