If It's a Hack and It Works, Is It Really a Hack?
I have a couple servers at home — one running Proxmox VE and one running Proxmox Backup. I use the VM server when I need to spin up a development environment, for running the odd game server, serving files locally, running Home Assistant, etc. I also like to donate spare cycles to Folding@Home. The backup server of course is in case I do something stupid on the VM server.
There's just one problem with that. My second-hand 8-year-old dual-Xeon server runs hot.
It was too much to keep running in my home office. Between the two servers, my desktop, and my work laptop, I was regularly seeing ambient temperatures around 26°C. It was just too warm for comfort.
Last summer I moved my network gear and the two servers into the front coat closet. This was great for me working in my home office, but not so great for my servers. Despite adding a passthrough vent to the closet door and a vent fan to the ceiling, the closet was still consistently in the 26°-30°C range.
The ideal solution would probably be to use an enclosed server rack and run an exhaust vent up from the top. Unfortunately, rack-mount server cases are expensive, enclosed racks are very expensive, and my closet is too small for that anyway.
So I hacked together a solution.
I built a frame out of some cheap 1x2 lumber and wrapped a piece of thin sheet steel around the sides to make a crude plenum. On top, I added a 10x6 register box with a semirigid vent hose coming out of it. This gives me a guide for drawing air out of the servers and guiding it up to the vent fan in the ceiling.
To help things along, I added a 120mm fan inside the register box. But not some whisper-quiet Noctua. This is (if the Amazon listing is to be believed) a 5000 RPM, 210 CFM monster of a fan. It's loud, but moves a lot of air.
Too loud in fact. Its droning could not be silenced by any mere closet door. I had to add a PWM fan speed controller to calm it down. It's a cheap unit from Amazon, but it came with a temperature probe and it has a configurable operating range.
The result? Where previously the entire closet was consistently above 26°C, now it's staying around 23°. There is a difference of 5°C between ambient in the closet and the air inside the exhaust duct, so it is doing its job of redirecting the hot air from the servers.
I call that a successful hack.
