The servers seem to be ideal at 30-40F. Any higher and they're a little hot or overheating. And I think they heat the room that they're in but I'm not sure.

Basically make a freezer for the servers.

you need -10°C at best

I've always tried to keep all the servers/skycores at 20F or below (the lower, the better IMO) if your having trouble getting to that temp, you may want to look into different ways to cool rooms. Personally, I usually use the walk in freezer unit from Dubs Bad Hygiene, since I don't need to deal with a hot side for the normal AC unit. But I do usually have to stack 4-5 of them in a row to keep up with the heat. But I also tend to have huge banks of servers and a few Sky cores, because I'm dumb like that.