best temperature for server room?

Hi,

here at the office we disagree in putting the airconditionar at 21? or 23? in the server room.
The server room is about 8m^2 and has 1 tower (2 meters hig)which has 4 servers and 3 switches and the telephonecentral in it.
If you disconnect out the Airco it heat up very well, especially in the summer.

I believe the airco must be put at 21? (min is 19?), althought some other people think that at 23? it won?t give any problem….

Any suggestions to end this in the office..

thx