Z's "Other Room" Water Cooling Loop Build Thread

[Zarathustra]

So,

For some time now (think years, if not a decade) I've been toying with the "what if" idea of, what if I just built a large enough water loop that I could relegate all fan noise to another room, and finally compute in actual silence.

In this thread I mentioned that I was probably about to either give up on water cooling, or double down on it. I think I have decided to double down.

When I got my Threadripper which outputs a good amount of heat, I thought about this more. And then once I picked up my XTX 6900xt EKWB edition which I overclocked such that it put out 430w for just the GPU, I became even more interested in this concept. Replacing the 6900xt with a 4090 has not improved things.

Not only can I get rid of that pesky fan and pump noise, but I can also sit in a room that is not stupidly hot in the summer due to having a 1000+w combined power output.

This build will be documented here in this thread AND in the Hardforums. The build will progress slowly, so don't expect frequent updates. A little here, a little there should do it. I may be done in a few months, or it may take a couple of years. Not sure yet. It depends on how much time I have and what the budget looks like over time.


I'm usually someone who thinks about my projects for a long time before I execute, and the planning phase is usually much longer for a big project, so to say I have given this some thought is a real understatement.

The high level plan:
- Build a water loop that has only the blocks in my office. All noise and heat emitting parts of the loop are in a different room.
- This "different room" will be my "server closet" which is about 50 ft away on the other side of the finished basement.
- Luckily the finished basement has drop ceiling panels, so running tubing up there should be relatively easy.
- Cooling may just be high speed fans and radiators, but if I am feeling like it when the time comes it may even be water chiller based.
- Loop will be a "two loop" solution.
- One long loop (pumped from reservoir in other room to office, pass through CPU and GPU block, and return back to other room back into reservoir)
- One short loop (pumped from reservoir to radiator/chiller and back to reservoir)



Slightly more details:

- I was originally going to use a soft Tygon-like tubing, but after discussing it in this thread I decided to go with PEX. Further research made me land more specifically on PEX-A, as I'm pretty sure the extended length of this loop will challenge my pump capacity, and PEX A has less flow restriction as fittings stretch the PEX out, instead of fit inside it, like PEX-B does.

- The plan is to use dual D5's for the big loop, and a single D5 for the short loop. I will be using PWM controlled D5 pumps, as I don't want them going full blast at all times. This means I'll have to run a PWM wire from my office to the remote room to control the pumps. This may or may not wind up working well. After discussing it here, I have decided to send the PWM signal either via a CAT-6a or better cable, or a coaxial cable, and hopefully the signal remains intact the 50+ft it will take to get there. In order to keep a shared ground, I am going to power those two pumps from my PC's power supply. I'll probably use normal solid electrical wire to carry the +12v and ground from my PC to the other room, and hope the voltage doesn't drop too much. Worse comes to worse, I may be able to use an ebay sourced cheap DC-DC boost converter to pull the voltage back up to 12v on the other end. Time will tell if that will be needed.

- I'm hoping to wind up using two water chillers. One small, quiet and power sipping one for idle or near idle power loads, and a second big, powerful, and potentially loud and power wasting one to supplement at high loads. I had been looking at the Hailea chillers they had on Performance PC's, but they have been out of stock forever now, and it seems unlikely they will come back into stock. I'll have to do more research to figure out which to use, but there seem to be a bunch of different models on Amazon to choose from. This may wind up being too much though, and I may fall back on just "lots of radiators and fans" instead. Time will tell.

- With the water chiller, I'd probably wind up running slightly sub-ambient. You know, below ambient, but above the dew-point, to avoid condensation. This adds some design challenges. Firstly, I'm going to want to insulate the PEX so I don't suck up too much ambient heat in transit.

- Secondly, compressors don't like rapidly switching off and on again, as this can damage the compressor. Most of them have electroic controls for this, that refuse to turn back on until a certain amount of time has passed (usually 3min?) since last shutoff. I want the system to be able to control the water temperature to within ~1C. This means that I need to have a large enough amount of water that even if the PC is dumping heat into it at full load (~900w?) I won't raise the average temperature of the coolant more than 1C in 3 minutes when the chiller is off.

- Initial heat transfer calculations suggest I'll need about 10gallons of coolant in order to limit it to a rise of 1C in 3 min with a load of 900w, but it's not quite as bad as that. Firstly, there'd be two chillers. Presumably if the big one turns off, the small one will keep running. Assuming the small one keeps removing about 250w of heat even when the big one turns off, that means I only have to deal with 650W, not 900W. This means I've now reduced my coolant needs to about 7.4 gallons. Add to that, the 900W is an absolute worst case power load for my system, which probably won't happen very often, even in an intense gaming or rendering session.

- Still, this means I am going to need a large reservoir. I am considering using a 6.5 Gallon wide mouth glass carboy usually sold for home brewing purposes. Using a specialty drill bit, I'd drill holes in the bottom and install bulkhead fittings to allow me to hook up tubing. The 6.5 gallons may not be quite enough, but there will also be just over 2 gallons in the tubing at any given time (according to my calculations) so it should be sufficient.

- I don't want to absorb too much heat into the glass carboy, so it will have to be insulated. I haven't measured things yet, but I think it should fit inside a small 20 gallon Brute professional trash bin. I'll throw together some sort of support structure (probably criss-crossed 2x4 scrap pieces) in the bottom, then put the carboy in on top and insulate under and around it using spray insulation foam. I'd then also glue some insulation to the lid, as well as cut holes in the bottom and the top for tubing to go through.


So, this is pretty much the plan thus far. I'm pretty sure that as I start working on it, reality will set in, and the plan will change several times, but at least this expresses where I am trying to go with it. I will post pictures and progress as I go along, but as I mentioned, it will be slow moving.

 

[LazyGamer]

Posting for support and subbing

 

[Brian_B]

Nice idea. I did something very similar (in a very general and vague sense of the word "similar") with my home hot water recirculator - which didn't want to work with a tankless water heater. But by god, two loops made it work.

Hmm... just thinking out loud - I would make the computer rig the short loop. I do understand the goal is to put all the pumps and fans outside the room - but that makes the loop transit time on the computer itself really really long and the one place I absolutely don't want issues is at the blocks -- the computer loop can keep a computer running even without the secondary loop running at all for a good while. I'd make that exception for one D5 pump, which aren't terribly loud all by themselves. Also, that would let you use a standard recirculator pump for the long loop then, which could be mounted in your server room and runs off 110V outlet - no 12V PSU or wall wart required. They are fairly inexpensive, very common / easy to find, and work with just about any "standard" plumbing you care to use. It's probably better suited than trying to double up a pump made to just run water inside of a computer case (even though the D5 is a stout little pump).

I agree 100% with Pex for the long loop, and I would think 3/4" would be more than big enough for a single computer. Pex even meets code in most places for running it inside of walls. Making the computer the short loop lets you keep the "standard" tubing inside of a computer (you could do pex in there as well if you want I guess, but it's a bit harder to work with and you may have trouble making up all the right fittings to most computer components). If you do the stretch fittings - they require a special tool but they are the best to use. There are push-to-connect fittings available as well (often under the brand name Sharkbite) -- they will meet your flow restriction requirements easily, do not require any tooling at all and are stupid easy to use, but they can have chemical compatibility issues that can cause them to leak if you aren't careful.

Pex, at least at the temperatures you are dealing with - won't suck up much ambient heat. The differences in temperatures aren't big enough that you are looking at much loss, and it's decently thick plastic and fairly well at self-insulating -- much better than, say, copper tubing. That said, since you are going active cooling, you probably do want to go ahead and insulate -- I know the goal is to maintain it above the dew point, but that may be hard to automate or maintain, and a little bit of insulation can prevent a giant mess and provide a lot of piece of mind.

Why a glass reservoir? That just seems like it would be difficult to work with. I guess it's chemically inert? I'd point to something like this if you are looking to spend that kind of money in the first place:

https://www.amazon.com/dp/B098Q9444J/?tag=thefpsreview-20

Standard stepper bit will drill through that and won't risk crack/shatter the jar while you are doing it, and same bulkhead fittings you were thinking of in the first place. And stainless is still fairly good at chemical resistance, plus choice of sizes if you wanted bigger/smaller.

 

[Grimlakin]

Ltt has a similar setup he's doing but using earth to bleed heat into. Interesting concept. I'd almost say do it internal to the basement and put in some led lights and translucent panels to show it off to friends and family for fun. You're already all in make it entertaining when you want to display it.

 

[Brian_B]

You're already all in make it entertaining when you want to display it.

Fog machine, disco ball, strobe lights, rotating bed...

 

[Grimlakin]

Fog machine, disco ball, strobe lights, rotating bed...

The 70s are calling they want their millionaire jigalo room back.

 

[Zarathustra]

As some wise person somewhere at some point said, the key to getting done is getting started, and in this post we are getting started. We have gone from the planning stage into the early execution stage.

So I did some additional research on PEX tubes.

As mentioned above, I had settled on PEX-A, as with PEX-B fittings go inside the diameter of the tube and can obstruct flow. For this project flow is going to be of great importance, so I wanted to do as little as possible to obstruct it.

Further research led me to this PEX specification page.

Lots of good information there that was helpful, including OD and ID ranges, weight of the tubing per linear foot, etc. etc.

My plan was to lay the tubing above the drop ceiling on top of the tiles at first, after which I will attach foam insulation around it, and then as a last step, screw it to the wood ceiling beams. I wanted to make sure the PEX in and of itself wasn't going to be too heavy for the first step, and damage the drop ceiling supports.

Turns out the weight comes nowhere near the level that would be damaging, so I am not worried.

What I also found on this page was the pressure drop table for various PEX tubing sizes:

I don't know if dual D5's will allow me to get there, but I am hoping to hit above 1GPM. According to this table 100ft (50 ft each way) of tubing length. I went ahead with the 3/4" PEX, as a 0.34psi (0.782 ft of head) seemed good enough, considering dual D5's put out 12.9ft of head according to the specs I have found.

I originally wanted to play it safe and go for uncolored PEX, as I didn't want to risk anyhting leaching out into the fluid. Remember, drinking water passes through the tube once, but coolant will circulate for a very long time, so there is greater chance of leaching, but I found an amazing deal on a kit that contained two rolls of PEX (red and blue) a good tubing cutter, and all the the compression rings for fittings I could ever want, so I went for it.
Turns out they are only colored on the outside anyway (though the light bleeding through makes the whole thing look colored)

I had never worked with PEX before. Turns out it is pretty stiff stuff, and it has a lot of memory coming off the roll. This could in part be due to working in New England Winter temperatures. I had to keep stopping my pull, and bending the tube back against the roll to straighten it.

You have to be careful when you do this, because bend too much and you can kink it.

I cut this piece out because of an inadvertent kink:

Turns out you don't necessarily have to do that. At least not with PEX-A. (the others you may have to).

With PEX-A you can heat it up with a hair dryer or heat gun, and the PEX material tends to want to return to its original shape. A hard dryer can take a while and be a pain in the ***. A heat gun can quickly go form not enough heat to too much, but it's better than having to cut out the section.

After that I just kind of had to pull it through the ceiling, tile by tile.

(Note the tape covering the end, so I don't get crap inside the tube)

And here we are, both tubes near their final destination.

(The electrical closet is attached to my office, and my desk is a few feet from that door.)


Next steps are too figure out how I am going to route these to my desktop. I was going to try to come through from the electrical closet, but I don't think that is going to work, so my current plan is to cut a hole in the ceiling tile above my desk, and run a couple of extra large cable raceways down from the ceiling to where my desktop is.

I am going to do 90 degree bends on both sides up in the ceiling before the tube goes straight down. (I hope too much air doesn't get caught in the top corners). Then close to the computer and close to the reservoir I am going to install hose barb fittings in the PEX to transition to more common water cooling tubing before entering the PC.

I have ordered some XXL cable raceways from Electriduct. Their largest size is 2x3". The OD of the insulation that is going to wrap around the PEX should be 1.98", so they should fit one per raceway.

Once I have the raceways figured out its time to buy lots of pipe insulation at Home Depot and start installing it around the pipes, and then install the hangers to the wood ceiling.

Most PEX hangers are designed to go around bare pipe, so I am going to have to do something else. I may use galvanized hanger strap around the outer dimension of the foam insulation and use that to support it. I am concerned that once th epipes are filled with coolant, it will be too heavy for the drop ceiling, so hanging will be necessary.


I'm also going to have to buy a PEX-A pipe expander in order to install the 90 degree bends. I'm probably going to use a manual one, as the electric ones are pretty **** expensive, and I am only going to be doing 12 joints.

We have:
Hose barb adapter near pump (one joint)
Tubing from pump up to ceiling -> 90 degree bend (one joint)
Tubing from 90 degree bend to ceiling tubing (one joint)
Ceiling tubing to 90 degree bend (one joint)
90 degree bend to tubing down to PC (one joint)
Down tubing to hose barb (one joint)

So that is 6 joints for each run, and there are two runs, so 12 in total.

I can use the manual stretcher for just 12 joints I think. No need to spend $600 on a battery powered tool...

 

[Zarathustra]

Ltt has a similar setup he's doing but using earth to bleed heat into.

I did actually review his "whole room loop" build from like 8 years ago to see if I would learn anything from it before starting.

What I did learn was that Linus is definitely NOT an engineer, and he made very many really dumb mistakes in that loop, which I will not be repeating.

He is an entertaining character to watch on occasion, but he is not exactly what I would call "knowledgeable about the physical world".

Anyway, I'm pretty sure LTT moved out of that house they had in that build years ago. It's crazy how they ahve gone from a small home operation to something that actually resembles a business. At least now he is hiring people who actually know what they are talking about instead of just pushing ahead with his lack of knowledge

The only thing I liked about his design was the soldered copper piping runs, but he hired a plumber to do that for him. Not all of us have that google money. Even so, the pluymber apparently forgot to solder one of the joints, which they didn't fiund out until they filled it, and it leaked. Whoops

Interesting concept. I'd almost say do it internal to the basement and put in some led lights and translucent panels to show it off to friends and family for fun. You're already all in make it entertaining when you want to display it.

Fog machine, disco ball, strobe lights, rotating bed...

The 70s are calling they want their millionaire jigalo room back.

LOL.

This is going to be an "all go, no show" design. There will be no RGB, and very little visible aspects of it at all, all hidden in the walls and ceiling and the server closet out of view.

Ideally if someone walks into my office, they'd never be able to tell it was even there.

 

[Zarathustra]

Hmm.

The plan was going to be to work on the raceways in my office next, so I could more and cut the PEX to its exact length, and do the 90 degree joints at the edges of the ceiling, but the raceway accessories I want are backordered until the end of May. :/

This is going to necessitate shifting gears. I wanted to hook up the tubing and flow test everything before I started building the reservoir, but maybe that order of things is going to have to change.

 

[Zarathustra]

The XXL Raceway's arrived today.

I also cut four 5ft lengths of PEX to serve as the parts that go up to the ceiling and back down again:



I spent some time trying to straighten them, even using some hot water in the shower, and this is the straightest I got them. I am going to stick them inside the unmounted raceway for a few days and hope that helps them become a little straighter, either way, once I put the insulation on them and shove them in the raceways, they ought to be straight enough.

I'm hoping the frame around the drop ceiling doesn't become a problem. I really don't want to cut into it, as I'd like this project to be reversible if possible.



It's about an inch thick, which will consume half the thickness of the raceway if I am not clever.

Has anyone ever seen 45degree PEX elbows? I figure if I use two of those instead of a single 90 degree elbow I can make this work navigating around the frame.

 

[Brian_B]

Has anyone ever seen 45degree PEX elbows? I figure if I use two of those instead of a single 90 degree elbow I can make this work navigating around the frame.

SharkBite 3/4 in. Push-to-Connect Brass 45-Degree Elbow Fitting U656LFA - The Home Depot

SharkBite 3/4 in. Push-to-Connect Brass 45-Degree Elbow Fitting is the fastest way to connect PEX, Copper, CPVC, PE-RT, or HDPE pipe in any combination. No soldering, clamps, unions, glue, or special tools required. Simply insert the pipe and the teeth bite down and grip tight, while a specially...

www.homedepot.com

probably have them in crimp if you look hard enough