I currently have 112 GPUs mining in my basement, and have a box of 28 more that are still not installed.
Basement is an unfinished cement open space of a 1950's little bungalow, about 1000sqft. Cards are installed into wireframe racks with 3" spacing between each gpu.
So far I've been dealing with heat with my house AC. It's a 2-ton unit. Works quite well. It works 24/7 and is able to keep the upstairs comfortable for 9 months out of 12. June/July/August things get hot. It doesn't help that I keep growing my miners every year.
The summer heat is really starting to annoy me. We have our first heat wave this week, and this is the first time ever that I needed to shut down miners so that I may live OK upstairs without cooking like a rotisserie chicken.
Last summer I tried putting my miners in a grow tent and exhausting this outside, but the 400cfm fan I had was inadequate, and cards were reaching 85-90c so I moved them back out.
This year I decided to get a 16" shutter fan, and mount it in a window. Based on
https://www.accu-tech.com/hs-fs/hub/54495/file-17645763-pdf/docs/cooling_enclosures_101_4-16-12.pdf I figured that I'd need about 1400cfm for 11Kw (140 cards), and the fan has 1800cfm at it's lowest setting. This should work I thought.
I sealed off all the AC vents in the basement to force all AC air to go upstairs. Opened the front basement windows just a little to let some air in without allowing rain to come in.
The first two days it seemed to be working quite well. I noticed though that the bathroom was unusually cool in the morning.
Then yesterday the Heat Wave arrived. And that was the real test of the setup, and it failed. My setup isn't working out quite like I wanted.
It seems like the 16" exhaust fan is sucking all the air conditioned air from upstairs as well as the hot basement air. That cool morning bathroom, it was due to the cool outdoors morning air being forced into the bathroom through the bathroom ceiling fan conduit. I taped it shut. Indoor temp reached 31.5c in the afternoon and didn't start going back down until 1am.
I'm doing a test now and shut down all my miners, and left the basement exhaust fan running. After a few hours like that, the upstairs cannot get lower then 28.5c. The big exhaust fan is clearly causing issues.
Based on what I read, what I'm experiencing was to be expected. I would also need some air intake with an identical cfm as the exhaust.
Before I go and spent more money on this, is anyone else having success in a similar setup as me?
As mentioned my basement is a raw unfinished one, and when looking up, I see the floor of the upstairs, meaning there is no insulation. I'm worried that even if I install an intake fan somehow and rearrange the airflow, it'll still find a way to mess the upstairs AC setup.
Alternatively I can just connect a 1-ton portable AC in the basement and deal with the extra electricity cost for 3 months.
I also thought about building a shed outdoors, but this being a small city lot I don't have lots of space, and the cost of extending my electrical setup 30-40ft to outdoors plus shed building would be more expensive then just running an extra portable AC in the basement.
What do you advise?
For those that just came for a picture, my setup looks like this:
https://pasteboard.co/JajJM2n.jpgThis was in January 2019. I now have a few more of those metal racks in the back of the wooden frame.
Show Posts
