I have a server room with two wall mounted A/C units. One is on all the time and one is a backup. During the day, the servers seem extremely slow, until I placed two fans directly in front of the two 42U racks. My philosphy is that the air coming from the A/C unit appeared to be getting lost in the room, until the fans was directing the air through the servers from front to back.
I have been told that I am allowed to purchase an additional wall mounted A/C unit and Now my question is, where is the best place to install it? Should one be placed at front of rack and one at the back???