Last summer, my friend and I decided to convert a large hole he had dug into a small underground facility where we could run our computers without having to worry about the noise. The bunker sides are reinforced with fiberglass panels with a 4x4" post at each corner, and has a roof made from two pieces of stainless steel sheet.

It tends to rain a lot in Washington, so we lined the sides with plastic, so if any water leaks in through the sides, it only runs down to the bottom where it is removed by a sump pump.

We ran power out to the bunker with an extension cord capable of supplying 15 A, and provided internet connectivity by configuring an old Linksys router with DD-WRT as a bridge. We have since obtained a remote antenna so that the receiver can be kept inside the bunker - safe from rain, dirt, and dog.

To moderate the humidity, we decided it would be a good idea to have something in the bunker that is always cooler than the surroundings. I constructed a makeshift ground source heat pump using 50 feet of HDPE hose, a Peliter module, an aquarium pump, a heatsink and water block, and a piece of plywood. The water is pumped from the reservoir through the water block, where it removes the heat transferred by the Peltier module. We buried the coil about six feet below the bottom of the bunker to absorb the heat. Water condenses on the heatsink and drips of into the pie tin, which directs the water into a hose and consequently into the sump bucket.

The bunker currently holds an HP Proliant server, two older Pentium D computers, and a small (mostly worthless) Bitcoin miner.


It's been raining pretty hard recently, and everything is still working as planned. (I still wouldn't put anything very expensive down there.)

This is pretty cool, is it in the open where you could put in solar panels? I feel like that would make the whole thing pretty awesome!

Huh, this seems like an interesting idea. Assuming that as you said, you have it sealed to prevent snowmelt and rain from coming in, how do you get the heat out? You talk about moderating the humidity to prevent condensation, but I'm a little unclear to where that Peltier module is pushing the heat (into the surrounding soil, I guess?). Thanks for writing this up! Although I'd imagine relatively few people are trying to build dedicated underground spaces for storing servers that aren't also rooms or houses, the techniques you've come up with seem like they'd have wider applicability.

Yes, the coil dissipates the heat from the Peltier module into the ground below. We currently do not have any dedicated systems for dissipating heat from the computers, although the ground is typically cool enough to keep the temperature down. Most of the rendering that the server is used for is done during the winter when heat isn't much of a problem. Ideally, the borehole would be much deeper and all of the computers would be connected to a central water cooling system.



It is in a backyard under some trees - but using solar panels would be pretty cool. The solar panels could power a cooling system during the day or something like that.

Hey, this is really cool. Can I ask why you're relying on Wi-Fi rather than running Ethernet, seeing as you already have power? I've done trenching to wire up this puppy for lights (and power outlets in the upstairs rooms), and I've also had the misfortune of dealing with long-range Wi-Fi, and I can tell you I'd much prefer the physical labor of the former to the unreliability of the latter, especially for server applications. If you're definitely sticking with the wi-fi, what have you done in terms of setting up a directional antenna to focus the signals?

Also, some of the ideas from the project I linked above might be useful to you for the cooling side of your project.

Also this project is pretty cool, I feel that the inspiration is very odd. You built an entire bunker to get away from noise?

That is really a simplified explanation for why we did this. The hole was already completed at the start of this project, so most of the work was outfitting it for computers. I didn't really have a problem with noise or space for my computers; however, his HP Proliant is extremely noisy. We had some computers

We had initially planned to bury a conduit for power and ethernet, but that got put on hold because I had to leave the state in a few days. The server is mostly used for rendering animations of CAD models for his (and previously our) robotics club, which doesn't require high reliability - especially if we process the frames on the server instead of transferring the raw data to another computer first.