Swimming pool cooled miner

[applegrcoug]

So I decided to do some hobby mining for a new tech challenge. It has been mentally rewarding. Maybe I'll break even someday.

So as part of this, I've taken a conglomeration of bits of knowledge I've accumulated in my lifetime and put it to use in a mining rig.

Back story...

*I am an apple farmer that deals with in depth pipe and pump designs several times a month. I understand water.
*I have a swimming pool at home that a few years ago that is heated by my home air conditioner. The AC refrigerant actually goes through a heat exchanger connected to the pool. The pool water cools the refrigerant before it goes into the compressor. The system works like a dream.

I figured I could use the same principal to cool GPUs. Specifically, 3080s because they get hot both on the inside and make my house hot.

Step one was getting waterblocks for the GPUs. Straight forward.
Step two was looking for a pump to circulate enough water through each GPU figuring I have to plumb them in parallel, not in series. I found a pond pump that I figured would deliver enough flow but not too much pressure. I don't know what the max pressure of waterblocks is and don't want to find out either.
Step three was a heat exchanger to stand up to pool chemicals and have enough heat transfer ability.

Then it was just piping it all together.

I've had times of it working all together, but it seems like I am cursed in the GPU department. I've had a 3090 with a bykski full cover waterblock on it from the get go....it keeps the memory at like 65, so I know it works.

One of these days it is going to be all done and working 100%!!

 

[Ferd]

This is awesome IMO , although probably not very efficient? To move water from the pool to the gpu requires relatively poweful pumps ? Also regarding the heat exchanger , is it necessary? I don’t know how much water volume you have available but it’s probably enough to go without an exchanger just dump the hot water on one side and pump water from the other end of the pool !
I don’t have much info on how you set it up but I love the idea , I was planning something similar i am just taking my time to understand different aspects , my goal is efficiency

 

[sam_86314]

Seems like a similar concept to this...

An issue they ran into was that the relatively low thermal mass meant that the coolant would heat up faster than the radiator could dissipate the heat.

With a swimming pool, it would take longer for the larger thermal mass to become saturated. Interesting idea.

 

[applegrcoug]

This is awesome IMO , although probably not very efficient? To move water from the pool to the gpu requires relatively poweful pumps ? Also regarding the heat exchanger , is it necessary? I don’t know how much water volume you have available but it’s probably enough to go without an exchanger just dump the hot water on one side and pump water from the other end of the pool !
I don’t have much info on how you set it up but I love the idea , I was planning something similar i am just taking my time to understand different aspects , my goal is efficiency

I would think the exchanger is necessary. Otherwise, you'd have to pump pool water onto the waterblock of the GPU and I don't think they are meant to handle pool chemistry whereas exchangers can be made to handle pool chemistry.

My pump I think is like 1.5hp, but it has a VFD, so it is clocked down when running through the exchanger. The biggest problem I have is I use a hose off the main line to feed the GPUs. Ideally, I'd plumb it into the mainline and get more flow without getting killed on friction loss. I don't have my charts handy, but that 3/4in garden hose pales in comparison to the 1.5in line.

 

[applegrcoug]

Seems like a similar concept to this...

An issue they ran into was that the relatively low thermal mass meant that the coolant would heat up faster than the radiator could dissipate the heat.

With a swimming pool, it would take longer for the larger thermal mass to become saturated. Interesting idea.

My two biggest issues I can foresee are:

what do I do when I winterize the pool? I'll probably just get some sort of car radiator and pump through it instead.

and

I really need more flow across the exchanger. See my other comment about plumbing direct. The garden hose is more of a proof of concept. Ideally, I'd relocate the thing to the pool filter shed.....except it got torn down to build a new one.

 

[Shrek]

In the winter you probably want the heat to stay inside the house.