Cooling a server closet (new home build)

My plan was to build an enclosed server closet in an attic and install a ductless minisplit on the ceiling. Then make the backside hot and the front side cool. This is only because it is REALLY hard to find resources on cooling a server closet.

How do you cool yours?
How should I cool this (it’s a brand new build so I can do anything)?

Thank you

I’m in the midwest, so we get cold winters and warm-to-hot summers. We also have basements with the ground temps being an even 55F year round. So, in my climate, I would avoid an attic as much as possible, in that the attic, even in the far north, is going to have times of the year with hot weather and super hot attics which are difficult to cool. On the other hand, a basement is easier to hold at a consistent temperature year round. The issue with basements, if there is an issue, is usually humidity.

Another thing to consider, is any kind of climate control first needs a climate that can be controlled. This means the structure must be air sealed and insulated. Different regions of the country will have different environmental factors/codes to consider.

If you choose to use a basement and it’s a relatively dry basement, you may get away with just putting the server in that space and being done with it. A more humid space may need either A/C for humidity control, or a dehumidifier. But also be aware that too much cooling can create condensation, which is bad for servers.

Where do you live? What are the conditions you face?

Great point. I’m in Dallas, TX so it’s really hot. My thought was having an insulated and sealed closet. In a walkable / insulated / sealed attic. With it’s own minisplit or whatever A/C is appropriate for this situation.

(We don’t really have basements in TX or it’d definitely put it there…)

Considering you’re down south, I’d skip the attic if it were my house. Instead, I would be sure my attic was balance ventilated at the eve/ridge. I’d be sure my attic was air sealed and insulated to R60. This would help greatly to reduce the overall cooling load on the house.

As for server closet, I would then find a place within the conditioned (A/C) space of the home for it.

I’m passive here too.

There are various reasons to not do this up in the attic. You would need to build an igloo around the rack. Also need to size the AC so that condensation on the walls/electronics is not an issue because your main goal will be humidity removal and less about sensible temps. A ductless unit is an excellent choice. You want cool dry air but not too dry either as that creates static.