I installed a 1U Dell server with vertical wallmounts in an office for a client early last year. They don't have a proper MDF/IT room, so this open space on a wall was the only location for the server. I had it pointed with the PSU downwards, mainly due to keeping wires neat, easier to see lights, hotswappable harddrives, and powerswitch. Room it is mounted in has a AC unit so temps don't fluctuate or get high. iDRAC hasn't reported any high temp issues. 2 Weeks ago the client contacts me asking me to flip the server around, so the PSU is pointing upwards. I push back saying the server is fine the way it is, there have been no temp issues in over a year, and I have other clients setup this way without any issue. They insist I flip the server around at my cost due to concerns of overheating. I cave and do as they told me to. Of course, while doing the work, I accidentally knock off the external backup harddrive onto the floor and it's dead. So I'm out labor and the cost of a harddrive, for no real reason. Trying not to let this bother me, but it does.