Project: melt's Self-contained residential "crate farm" of mining rigs using cheap materials

[melt]

Project: melt's Self-contained residential "crate farm" of mining rigs using cheap materials

For this project I wanted to try to contain the heat and noise for the summer for my 20-GPU farm, and our basement is quite small. About 8 feet to the left of this farm is the inside air handler and open return duct.

To enclose the 2x4 foot rack, I purchased a 2x4 foot by 60" tall mylar grow tent. This was wrong, I should have gotten 4x4 foot. There needs to be a good amount of space in front of the GPUs for airflow. In this configuration, when you zip it up airtight, it sucks in with negative pressure and the ambient temp goes up to 100F (or higher if I didn't open it back up.)

Saddest part was de-constructing the "PiMP Tower Build" to make room for this. However, that build was mostly 120V, and also, it's still in the attic in case we expand some more, haha. You can see it in the photo looking jealous.

Construction Materials

I prefer to use the wire racks and zipties to house the GPUs.

For motherboard standoffs (to keep them off the metal rack) I use 1/2" PVC pipe, about $3 for 8 foot lengths at Home Depot. One stick cut in two 4 foot halves does one rack.

We had to make sure there was a little extra clearance on the end GPUs to let a little more air flow. The mylar does reflect the heat back. But that's better than materials that melt.

I zip tied the ASUS 21" Monitor onto the rack and have a 15 foot HDMI cable and a keyboard for when a rig doesn't respond via SSH, for local troubleshooting and testing, and for QA (Making sure desktop functions work on PiMP.)

The thermometer was a gift from a friend, for the shop, repurposed here. And those are PiMP Green LED Christmas lights for fun and for a little extra light.

First attempt - unit inside the rack

This was a bad idea overall. Not only did it take up a ton of room that we needed for rigs, it simply didn't work. The unit has to be outside. Obviously a mini split system would be even better, but those cost a lot more than $260.00.

Mining Hardware

Most of the GPUs are ASUS DUAL GTX 1070s and most of the motherboards are ASUS PRIME Z270A. As you can tell, big ASUS fan and they have been very good to me. I use all ASUS monitors now and they are terrific. Most of the power supplies are DELTA 240V 2400W. All custom electrical work including the wall meters done by me.

Winter mode

For recirculation in the winter, simply ziptie some box fans on and the air returns will take the air back to the air handler's return. I put the heater on fan-only mode 24 hours, and the warmth of the rigs flows out of each supply register in the house. Last winter I did not have to fire the furnace but for 1 very cold day!

Summer mode

In summer mode, I purchased an LG 8,000 BTU portable A/C unit which uses about 850 Watts. Should have gotten a 10,000 BTU instead, but this one was a good deal, and it ran stable all summer. Ambient in the farm was about 80F.

In order for this to work, we had to use 8" flex duct and quality metal tape and sheet metal takeoffs to get the best air flow from the unit to the farm. And we were surprised to find out that the best performance was when we dumped the cold air supply on top of the gpu's at an angle, and the return at the bottom.

I also grabbed a roll of 3mil plastic sheeting and sheeted the whole room off from the rest of the house to further isolate the heat.

Then I got more PVC and "extended" the grow tent frame with PVC and duct tape, so I could add another layer of plastic sheeting. I was careful to keep it away from the heat of the cards for safety.

You can also see in the above pic that I do have some of the dev/test rigs on Z-Wave smart plug controllers. Those rigs only have a few GPUs on them and are running at a low wattage, in order to account for these.

Results

Uptimes are great! And looking forward to more free heat this winter. So for about 850 watts, took the load off the main A/C unit and kept the basement office and the laundry a lot cooler than last year.

Thanks for looking at my post. Please comment below or ask any questions you have.

We really hope to see more people write up and post their rigs and farm ideas here to help one another.