Project: External Cooling

[Dirk Diggler]

Warning: this project probably won't be much to look at, it's more about the best way to set things up for optimal cooling etc.. (I know, yawn )

Something I've wanted to do for a while is have a system that's full custom water cooled, but have the cooling separate from the room I'm using the PC in. Because over time I've realised that even with water cooling, the heat has to go somewhere. I really noticed this when I moved house as my system is in an office downstairs, and while the office is plenty big for a PC system I've really noticed the heat build up from the radiator fans and particular with VR the room gets really toasty (I don't think the foam headset helps).

Luckily, my office is adjacent to my garage so I have some interesting options.

I originally planned to use an external radiator by an open window, and while I was seeking some advice on the best way to do this (intake versus extract etc..) things just kind of... Well grew arms and legs I suppose.

I'll update the next post with where I've got to so far, and hopefully I can get some advice on the small details in terms of what components to use, how to set up the radiators etc..

 

[Dirk Diggler]

This is the PC as it's set up at the minute.



What I want to achieve, is to have the CPU & GPU under water with custom blocks and have nothing else in there in terms of water cooling. No radiators, pumps, reservoirs or anything else that will produce heat or noise. I'll keep the inline temperature sensor there as I'll need to hook that up to an Aquaero LT6 that's in the PSU compartment. I'll also keep some case fans but they'll only be called into action if they are needed, so will be 0 rpm unless required.

 

[Dirk Diggler]

I had to get a radiator into the garage and do some testing to see how this will work out so first up, it's some hammer action with the battery drill. I routed 2 hoses and also a signal cable for the PWM control of the fans to the garage next door.









Next, I bought some shelves from Homebase, a bargain at £20 IMO.



I then stuck some swivel 90 fittings on and connected up the external hoses.











Next, I hooked the hoses up to the external radiator. I've made it so that I can easily disconnect at the radiator and drain if I need to, and I've stuck a 600w EVGA PSU in there to power the 4 fans.











This is how I could've left it, however the Mercury hit 0 degrees and I'm realising that there's going to be icicles hanging from my 1080Ti come January

So I had to think err.. inside the box.

 

[Dirk Diggler]

Was very interested in your other thread about this.

Just a thought, would it be good to have 2 quick disconnects at back of the PC so you can disconnect the PC from the external loop with ease?

Yes, I'll have one more post to update and that'll be me up to date with where I'm at just now.

I did consider quick disconnects, but the way it is just now is actually really easy. When I unscrew one tube very little water comes out because there's no way for air to get in and replace it. All I do is disconnect one line, fit caps and then disconnect the next line. Quick disconnects are quite expensive and they take up more room than I'd like.

 

[Dirk Diggler]

I decided to fit a little bypass and then mount the radiator properly.











I boxed it all in and applied some insulation to make it snug. I've also installed an anti-condensation heater and a frost stat.









Finally, I've installed a little flap on top that will keep the heat in if it's Brrr.. and this will lift up automatically to let the hot air out when the fans ramp up to 100% when gaming.





This is working really well. The room is now comfortable no matter how long I've been gaming, and the loudest component is now the PSU (that'll need to be dealt with). As mentioned in the OP I now want to get all the water cooling equipment into this external enclosure. There's also some wee improvements I want to make.

I'll now have a wee think, seek some further advice in the relevant section of the forums and update as I progress.

 

[Dirk Diggler]

@D1craig that wouldn't work. I had to buy a 900mm long thermistor cable to get from PC to garage and it only just reaches.

@Mercutio I had thought about that originally, but I ruled it out due to the amount of cables I'd have to bring back through, particularly USB as I have a VR setup plus wheel and pedals etc.. what kind of hub would reliably provide the USB interface?

I also think I'd need to keep it custom water, because I'd have performance issues in summer, particularly with the Pascal GPU. As you say, I could ditch the case and make a bespoke setup. This is definitely an option.

 

[Dirk Diggler]

Did you take note of temps before and after? If it is anything like my garage in the summer it gets roasting once the sun hits, the insulation will help then also.

Yea, it's a strange thing I'm seeing (well, strange IMO). Temperatures were too good when I had the radiator just sitting on a shelf in the garage, which is why I knew I had to install the insulation and heater etc.. else the water would freeze. However, it's pretty much identical to having the radiators in the case now that I've installed the insulated enclosure. It's like the enclosure is just an extension of the office, and I actually think the 240 radiator in the PC case helps this as it heats the fluid up as it tries to equalise with the case temperature (22°C). I also think when the external radiator fans are at 30% (250 RPM) that instead of pushing air out of the enclosure, it just re-circulates it around and heats the enclosure up. This is excellent in winter, but as you say come the summer it'll be too toasty.

I've actually reversed one of the fans in the internal 240 rad so that when the fluid is colder than the office room temperature it actually pulls the cool air into the case, which keeps the motherboard etc.. cool and it also helps to heat the fluid back up as it is essentially pulling hot air from the office through the internal radiator and that in turn gets transferred to the external enclosure via the external radiator. I'm convinced that this system relies on the two radiators equalising with each other at idle to ensure that the water can't freeze.

When the PC is gaming, the internal radiator fans go to 0 RPM and the external radiator fans go to 100%. The downside to this is that the external radiator isn't getting the benefit of the colder air when it really needs it. I sort of want to have my cake and eat it.

This is working really well just now, but I definitely need to refine the design for 24/7/365 use. Here's a snapshot of what's going on just now as maybe a picture can explain things better than the written word. Look at the external enclosure temperature; 12.5°C. Look at the fluid temperature; 22°C. The external fans are hovering around 200 rpm and the internal fan is pulling cool air off the radiator at 400 rpm. The outside air temperature is currently 5°C, but the enclosure is in double figures and the fluid is 10°C warmer again... and the anti-frost heater is never called into action (it's set to come on at 7°C but it's never been that cold in the enclosure, even though the outside temp has been as low as -2°C).

 

[Dirk Diggler]

To be honest, I am not sure being inside the garage water would actually freeze.

I have never had water I store in the garage freeze as although it does get very cold never cold enough to actually freeze. This is both in an integral and separate garage.

If it was me, I would try running with the radiator it the enclosure again and see what you can actually achieve temp/overclock wise!

I'm not sure where you live, but in Lanarkshire it isn't unusual to have temperatures as low as -25°C in winter. Freezing isn't the only risk, I also need to make sure the fluid doesn't get too cold or there is a risk of condensation on the GPU and associated tubing in the PC. Basically, if the fluid was e.g. 4°C and the internal case temperature was 25°C I'm pretty sure I'd end up with condensation.

Whilst low temperature would be interesting from a performance point of view, the primary purpose of this setup for me is to get the heat and noise out of the office and into the garage. Also, in terms of day to day GPU/CPU performance it's actually more beneficial to maintain a consistent low (15°C) temperature than it is to hit very low temperatures. The only way to acheive consistent low temperatures is:

• Maximum radiator space
• Highest possible RPM on the fans when the rig is under load.
• Lowest possible air intake temperature when the fans hit 100%.

That's the 3 areas that I'll be focused on when I do the new enclosure. The low air intake temperature will be the hardest one to achieve, due to the condensation risk. Basically, I can only allow low temp air intake when the fans are at 100% RPM so I need to devise some sort of damper system.

 

[Dirk Diggler]

Update: Design plans are taking shape.




It's a two compartment system, where the lower compartment is doing all the cooling to the fluid via Radiator 3 with fan C pulling in all the cool air that gets blown back out the bottom via the radiator. Even if the ambient is in the minus, fan C will be 100% because the cooling process will only be triggered if the fluid is getting hot (rig under load). This is crucial as it means I can take full advantage of freezing temperatures without risking frozen fluid or condensation.

Radiator 2 exists for the low winter temperatures and it'll prevent the components from freezing. During mild/summer weather, the fans on this rad will be 0 RPM and the radiator will be dormant/passive. - I might not include this in the initial build, as radiator 1 may be enough.

Radiator 1 will kick in when required to assist radiator 3 in the summer, and will be passive when not required - during winter this rad may be enough to heat the enclosure if the fans are low RPM. Fans A & B will assist with the cooling during summer by feeding in cool air and pulling out the hot.

Fans A & B will only be called into action if the top compartment goes above a pre-determined (hot) temperature.

Fans A, B & C will probably be 140mm and will open and close dampers depending on whether they are required or not.

The fan damper system is the curveball as I don't know yet how to achieve that part of the design, but it's definitely a pivotal aspect so needs to be worked out. I won't be doing any work on this until I've sussed out how to get a 140mm PC fan opening and closing a damper flap with success.

I will include a heater and frost stat, I've just omitted from the graphic for clarity.

All temperature control and fan control will be handled by an Aquaero LT6.

 

[Dirk Diggler]

Small update, I'm continuing to monitor temperatures as I need to know how things work in reality before investing time in design and construction. My PC will idle for another two weeks as I'm at work for the next fortnight, so it's a good time to collate data. Idle temperatures are most interesting in winter because that's where all the risk is (freezing fluid). My wife has informed me that there's been frost the last few days and as you can see my fluid temperature has remained around 20C which is much higher than I would have expected.

Great for winter, but definitely not good for summer. I need to ensure my final build is versatile and able to adapt automatically to the external influences.

Click on image to enlarge.

 

[Dirk Diggler]

It looks like I'll have to modify my plans based on the testing to date. The temperature has plummeted to -7°C and this has meant my external enclosure temperature has lowered to around 6°C. I won't know until I get home whether the anti-con heater has been called into action (I've got a power meter on it) but I've got a sneaky feeling that it has as it's set to kick in at 5°C.

What's interesting is the fluid temperature, it's still hovering around 20°C. That's pretty much mission accomplished right there as it proves that even with external sub zero temperatures, the enclosure is keeping itself above 5°C and amazingly the fluid temperature is staying at room temperature - so no chance of freezing.

The only way fluid can be so much warmer than the enclosure it's in has got to be down to the internal radiator in the case pulling the warm air from the office through into the case. It's not only keeping the fluid warm but it's also keeping the components in the case cool.

I need to cancel my plans to move all my cooling gear to the external enclosure, it's just not going to work when temperatures are sub-zero. So, this system has been idle for 4 weeks which has been a great test in terms of freezing fluid risk, however it's now time to pound some gaming and see how that's working out in these freezing conditions.

Here's a graphic of what's been discussed in this post.

 

[Dirk Diggler]

Yes, I've got additive in there.

I've ordered an Inkbird ITC-306UK and the plan would be to have the heater plugged into one socket and the radiator fans plugged into the other socket. Radiator fans would kick in at 25C and heater would kick in at 15C. I
would expect the water to be 20C or higher 90% of the time so the heater is essentially a fail safe for really cold weather.

I would need to set this up with a little tank with a couple of litres of water in it, so I'm thinking even a low wattage heater would do? What would you recommend if someone was asking for a quality heater for a small tank?

 

[Dirk Diggler]

@opstrat thanks for the link. 10w is really good as it'll be economical to run. I'm pretty sure I can set this up so that the water is maintained above 15C but I just need this fail safe in place. I've got a space heater in there just now, but it's creating complications when it comes to efficient cooling.

Anyway, thanks again. I'll pick one of those up and have a think about how to include a container with a few litres of water to house it.

 

[Dirk Diggler]

@WJA96 I've lived in Lanarkshire all my life and can assure you it isn't warm. However, the -25C I should have described as "not unheard of" as opposed to "not unusual".

Anyway, it's a moot point. My plans have been classic over engineering. The Mercury has hit -5 this winter and my fluid stays above 20C. It's just not going to freeze due to the amount of time the fluid spends in the office side of the loop which is always around 25C. I leave the external fans at 200rpm and the fluid is 20C+ no matter what the garage temperature is. As soon as the GPU goes under load the external fans ramp up to 2000rpm.

The result is a GPU temperature of 20C on idle and 27C under full load. It's well and truly mission accomplished.

 

[Dirk Diggler]

Is this still going @String

I got it finished.

https://forums.overclockers.co.uk/threads/itx-custom-loop.18817860/