Nice you caught it in time. Warm, moisture latent air will condense on cold surfaces.

Once you get that GPU on water, your loop temp will go up but you also lose a local source of heat (convection and radiation).

You know why [building] radiators are traditionally placed under windows? To mitigate condensation.

You can’t control the outdoor temp so it’s quite risky.

I wouldn’t be comfortable running that system when your loop temp is below dew point. You’ll have to insulate your blocks too. Otherwise you may find condensation on your 4090 block.

In other words, be careful! I’d find a location for that rad where temps are more stable. Even if warmer.

 

Nah, just need to throw more heat in there and things will be great! Curious as to what OP does in the summer, however. With the temperature swings we have in the states, there is no way that would fly here.We can go from -11 to +38C from winter to summer in a NORMAL season in the northeast.

 

are you satisfied with EKWB products?

 

It sounds like the issue was leaving the MO-RA in that unheated attic. Which means it's bound to get worse as outside temps stay subzero for extended periods of time.

You should look into insulating the tubing that travels to the MO-RA if you want to be safe over the long term.

 

It sounds like the issue was leaving the MO-RA in that unheated attic. Which means it's bound to get worse as outside temps stay subzero for extended periods of time.

You should look into insulating the tubing that travels to the MO-RA if you want to be safe over the long term.

As I explained already in the main post, things do balance themselves out assuming everything is watercooled and dumping heat into that attic room. I was using this setup for 2 years already with 6900K/2080Ti SLI and everything was always within safe margins, the room was never below 8-10C and dew point inside the case was below 5C because the main room is temperature and humidity controlled with AC and there were no major heat sources within the case. But now the temporary situation is that I do not have GPU waterblock yet, so not only I am not heating the attic room up with GPU heat, but heating up main room instead, so everything went completely out of balance. It will be fine once the GPU block is in, temp within the case will go back to 19-21C, so dew point will go back to 5-7C, and attic room temp will go back to ~8-10C at the worst, so water will be like 11C idle.

Even in the worst case scenario like this one I was only a few degrees off, just lowering the case temp by 2C and increasing attic temp by 2C would avoid the problem.

Having it like this during winter is great as it is basically a free water chiller, but one condition is that the heat from PC has to be dumped into radiator room to maintain good temperatures there, which cannot be done without GPU block. I have to wait till 22/12 for delivery so I will have to actively heat that room up temporarily.

 

^ That only works assuming your temp in the attic stays at a constant temperature or doesn’t drop further.

Assuming you live in Poland, I know most residential houses don’t insulate the roof. Rather it’s the ceiling plane beneath the bottom of the roof trusses or beams. Or in other words - the attic is unconditioned.

It can get also get quite cold in the winter. Not as frequent or drastic as Canada… but I’ve spent a lot of time in małopolska, and it does drop to negative temps frequently in the winter.

As long as you’re confident a constant 400-500w being exhausted by your radiator will maintain a decent temp in your attic, you’re OK. An idle system will keep blocks warm, sure… but your loop temp could still be below dew point on very cold days and you still risk condensation.

I also still think you’re underestimating how the air cooled 4090 is influencing behaviour in your case. Dew point isn’t just based on ambient temp.

I would advise reconsidering the location of the rad or at least insulation. Even a semi-enclosed enclosure around the rad to mitigate some of the cold is an option.

The risk for a short is high given the volume of most attics and the unknown temperatures of an unconditioned attic in the winter.

 

Well, I am actually a roofer, and I have the roof insulated because I live there. It is divided in 3 rooms, one is my room which is under AC and very insulated both thermally and acoustically, one is corridor, and one is this attic room. It is like a 3x3 room with reclined celling from the roof so the actual volume is more like 2x2 room, it is not hard to maintain temperature there, there just need be some heat source, which there isn't right now, and I had a roof window slightly open because this room also serves as a mini gym you could say.

Also for the summer I have it configured so that the rad is pushing hot air to the outside through the wall, and I still haven't disconnected that, so whatever little heat I was producing from CPU benching and etc was going to the outside. It is just the weather was unusually good this year and I was caught off guard by the sudden temperature drop. There was also first snow today and there is already 6-8cm thick snow everywhere, it is just insane change of weather in just one day. Combined with the fact that I don't have GPU block yet, it was like the worst combination of circumstances possible. And even with all of that it was still only slightly off by few degrees. I am confident it will be fine once the loop is complete.

 

Ah - you’ve should of clarified from the start it was a conditioned space! This my frame of reference:

Look - my posts were just to flag the risks and seems like you’re on top of it. Just don’t want to see you fry your hardware

 

Ah - you’ve should of clarified from the start it was a conditioned space! This my frame of reference: View attachment 2583820

Look - my posts were just to flag the risks and seems like you’re on top of it. Just don’t want to see you fry your hardware

My main room is conditioned, radiator room isn't, but it is insulated, not very well and roof window is very old and not good, but still

I get what you mean, I didn't take your post as an offence, your points are correct and this whole situation here has a pretty tight margins, so is understandable that it would raise concerns. I certainly wouldn't recommend something like this unless someone really knows what he is doing and has sensors monitored at all times, and even then, one mistake or combination of bad circumstances, like what happened with me today, could be lethal.

Looking at how long it took the condensation to form and how it still didn't drip despite sitting like this for ~10 hours with water temp 6C below dew point I think the mistake would have to be very big to cause some serious damage, so it is not like you go one degree below dew point and everything explodes and it is not easy to do something like this in the first place, this is a very unusual situation, but still.

 

You should see what happens to a matte LCD outside in -20c

 

@Krzych04650

You need a waterchiller. it’s so easy to stay above the dew point and never ever get condensation on your hardware. Unless you want condensation lol.

I can just set a 13C-14C water temp year around. And never ever worry with it. You can go a little cooler in the winter though if you like. And if you want to bench or keep it even colder, just properly prep your motherboard for the condensation. And run the water at 3C. It’s so easy and reliable!

I run a chiller 24/7. I don’t even need my enormous external radiator anymore.

 

@Krzych04650

You need a waterchiller. it’s so easy to stay above the dew point and never ever get condensation on your hardware. Unless you want condensation lol.

I can just set a 13C-14C water temp year around. And never ever worry with it. You can go a little cooler in the winter though if you like. And if you want to bench or keep it even colder, just properly prep your motherboard for the condensation. And run the water at 3C. It’s so easy and reliable!

I run a chiller 24/7. I don’t even need my enormous external radiator anymore.

View attachment 2583906

View attachment 2583907

I wonder if my chiller will work for that. 😁
No worries, not a meth lab. Home canna. 100% legal.

EDIT:
The blue Crystal Head Vodka bottle is being used as a weight. The blue dye in the water is Feser View Active UV Dye. As a testament to its integrity, that dye has been inside that bottle since before 2012. As a matter of fact, whenever it was Darthbeavis used one of these vodka bottles in a build, that was about when I filled it. I sent one of the vodka bottles to Darthbeavis. I actually managed to cut a clean enough hole thru the bottom of a 40 pounder version to make a PC reservoir. Wasnt overly hard. Need a longer bulkhead fitting than what PC water cooling has. To lazy/busy to fab/source it. Didnt pursue.
The reason for the lab?
Holistic medicine for myself. ADHT/anxiety. I avoid pharmaceuticals the best I can. I dont trust even the Gov pot shop supplies. Most commercial suppliers use some very ugly solvents and chemicals for extraction and processing. I make my own medicine. Then I know what has gone into it start to finish. Use Everclear. 190 proof, 95% Ethanol. Food grade. People have been drinking it for centurys.

 

What a risky setup. I keep my whole system air cooled cause liquids scare me lol. I'm not breaking any 3DMark records, but i can sleep alittle more easy at night.

 

For what it's worth, I've done one custom loop, but have used AiOs for years. Never had a leak.

 

oops

 

Until you devise a more permanent solution, you could disable c-states so that your water temp won't drop so low while idling.

 

The thing with dew point is that it doesn’t change with air temperature. It is purely only related to the water content by mass in the air. How close the air temperature is to the dew point basically determines relative humidity. The only way to prevent condensation is to always keep water temperatures above the dew point in the room, or remove moisture from the room air to lower the dew point.
Raising the room air temperature may seem to help, but only because you are increasing the differential temperature between the outer surfaces of your loop and the actual water temperature due to thermal resistance of the materials containing the water. That effect is highly sensitive to localized air convection around the components and nearby radiant heat sources. Your safest bet is to just keep the water temperature above the dew point. You could put a thermostatic 3 way valve to blend radiator supply water with recirculated computer loop water and just put the sensing probe on the supply headed to the computer and set the control temperature of the valve to something safely above average ambient dewpoint. That way you get consistent cooling supply temperature no matter how cold the radiator gets. You could probably do the same thing with an Arduino microcontroller and a temperature sensor controlling some kind of servo valve, and in that case could incorporate an ambient humidity sensor for a dynamic water temperature setpoint that raises and lowers with ambient dew point changes.

 

Keep your computer in a box that continuously dehumidifies itself.