I have a small computer room with to AC units designed and installed to keep the PC equipment at operational temperature.

One of these units is broken.

Whilst it is under repair should I:

• leave the door open with a fan for circulation AND swich the AC off
• leave the door open with a fan for circulation AND leave the AC on.
• close the door and leave the one AC unit to cope.

Outside it's winter, the rest of the building/floor is at room temperature or slightly above and is open-plan.

ExH

I would try the door closed and one AC unit. The 2 may have been sized to work in the summer when heat leaks in, not out. This also keeps out dirt. If it has to run continuously, then open the door and use the fan. Leave the air conditioner off unless it starts getting too warm.

Keep the door closed. Turn on one AC if required. I fully agree with the previous comment.