# Avoiding condensation



## xH2L

In order to avoid condensation, is it as simple as making sure the coolant temperature doesn't drop below the ambient temperature? I'm curious because I'd like to create a shroud, or cold-box, to place around my mora, and see if I can drop temps to near-ambient during overclocking, using a standing A/C unit that I have. Though I'm not entirely sure it will prevent condensation all together, because only the mora would be placed in the cold-box, and not the rest of my bench setup. Which means fittings and cpu/gpu blocks would be exposed to higher ambient temperatures than what would be inside the cold-box, right?


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## o1dschoo1

xH2L said:


> In order to avoid condensation, is it as simple as making sure the coolant temperature doesn't drop below the ambient temperature? I'm curious because I'd like to create a shroud, or cold-box, to place around my mora, and see if I can drop temps to near-ambient during overclocking, using a standing A/C unit that I have. Though I'm not entirely sure it will prevent condensation all together, because only the mora would be placed in the cold-box, and not the rest of my bench setup. Which means fittings and cpu/gpu blocks would be exposed to higher ambient temperatures than what would be inside the cold-box, right?


Stay above ambient or liquid electrical tape the board then use art eraser pack it in and some liquid electrical tape on the back of the board. I can help you insulate it if you wanna go sub ambient.
If you are doing a cold box ambient temps would be whats inside the box.


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## o1dschoo1

Ok i just reread your post if you wanna run a ac unit straight into your rad it will probably drop below ambient tbh as room temps will be higher than whats coming out of the ac .. i thought you meant by cold box is running your ac into a actual sealed box to actually create a separate low ambient enclosure.. that would not condensate.


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## Slaughtahouse

Condensation occurs at the dew point. Dew point is based on relative humidity and dry bulb temp IIRC.

Or in other words, when moisture latent warm air hits a cold surface, the water will condense.

You can do the calc pretty easily but the challenge is controlling humidity. Unless you have a well controlled environment, it could be difficult. So the dew point could change.

For instance, in Southern Ontario (Canada), RH is commonly around 80-90% during the summer and could be 30-40% or less during winter.

The AC unit will have to pull in ambient air to cool and exhaust the heat. It’s unlikely the AC unit will manage to get the air feeding the “cold box” below ambient and of course, you will be able to control it.

The overall risk is low but you’ll have to manage the AC unit carefully initially just to make sure it’s not getting your loop temp to like <15C.


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## StAndrew

Correct me if I'm wrong but technically, temps have to stay above the dew point, not ambient.


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## o1dschoo1

StAndrew said:


> Correct me if I'm wrong but technically, temps have to stay above the dew point, not ambient.


Correct but they are pretty close depending on a few variables like humidity. 
Its alot easier to just say stay above ambient while you technically could drop a few degrees lower it starts getting tricky.


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## o1dschoo1

Gonna followup on my last comment. Your gonna have to do the math on dew point every time you crank that setup on and getting that close to dew point id honestly insulate anyways. All its gonna take is one screw up on that math and your condensating all over your rig. While condensation isnt a big deal if you catch it right away hit it with some denatured alcohol and let it dry its a pita and lethal to your pc id you dont catch it.


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## Slaughtahouse

^ Not necessarily.

Could you (OP) explain the cold box in further detail?

Keep in mind an A/C technically doesn’t provide cooling. It’s actually removing heat.

What you’re feeling is simply the absence of heat. I mention this because… to get below ambient (conditioned or unconditioned air) is likey very difficult for any standard residential, portable AC unit. 

As once you approach ambient, the AC unit will not only have to remove the heat inside the box, but also the heat surrounding the box.


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## Slaughtahouse

Just a quick follow up to explain in more detail.

I have this portable AC unit. 10,000 Btu/H

Yellow = intake (ambient)
Blue = exhaust (cold air)
Red = exhaust (hot air)










Your cold box, I assume is just duct work from the BLUE to your rad? If so, keep in mind your A/C unit thinks its trying to cool the intake air (your ambient, conditioned or unconditioned air).

I’m not sure how the A/C reads the temp but likely it has a sensor near the intake.

So your A/C really isn’t trying to cool your radiator (cold box), it’s really trying to cool the air feeding the unit.

Meaning, keep in mind what I initially said. It’s unlikely the cold air to be less than ambient but monitor it closely when you first set it up.


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## StAndrew

Slaughtahouse said:


> Just a quick follow up to explain in more detail.
> 
> I have this portable AC unit. 10,000 Btu/H
> 
> Yellow = intake (ambient)
> Blue = exhaust (cold air)
> Red = exhaust (hot air)
> 
> View attachment 2524280
> 
> 
> Your cold box, I assume is just duct work from the BLUE to your rad? If so, keep in mind your A/C unit thinks its trying to cool the intake air (your ambient, conditioned or unconditioned air).
> 
> I’m not sure how the A/C reads the temp but likely it has a sensor near the intake.
> 
> So your A/C really isn’t trying to cool your radiator (cold box), it’s really trying to cool the air feeding the unit.
> 
> Meaning, keep in mind what I initially said. It’s unlikely the cold air to be less than ambient but monitor it closely when you first set it up.


A/C's are heat pumps. They just move the heat. What your picture is missing is ducting for exhausting the heat out the room/window. Without ducting, the A/C is actually a heater as the net air temps will actually go up due to waste heat from compressor and fan.


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## Slaughtahouse

Yes, the photo I grabbed from the internet didn’t have the exhaust pipe. I tried to draw the heat in a direct line to illustrate it.

Still the same principle. A/C unit will have the be placed near a window to exhaust (move) the heat out of the environment/room.

My point is… will the A/C unit cause the loop to get below ambient? I don’t think so but I’ve never tried this. Also seems insanely inefficient


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## o1dschoo1

Slaughtahouse said:


> Yes, the photo I grabbed from the internet didn’t have the exhaust pipe. I tried to draw the heat in a direct line to illustrate it.
> 
> Still the same principle. A/C unit will have the be placed near a window to exhaust (move) the heat out of the environment/room.
> 
> My point is… will the A/C unit cause the loop to get below ambient? I don’t think so but I’ve never tried this. Also seems insanely inefficient


It really is. If you have a spare window unit for this just pull the fan off of it and put the condensor in a ice chest filled with glycol.. phasechange water chilling is pretty efficient and the route im probably going for benching.. thats if i dont go full singlestage phase.


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## Asmodian

Slaughtahouse said:


> Meaning, keep in mind what I initially said. It’s unlikely the cold air to be less than ambient but monitor it closely when you first set it up.


If the A/C unit cools the intake air down at all, won't it be below ambient? It won't cool the room below ambient in that configuration, but it will cool the exhaust below ambient.

I have seen the exhaust from an A/C unit cool down metal objects in front of it low enough to condense water when exposed to ambient air. It is pretty common for the outside of the box to condense if you trap the exhaust somewhere. The exhaust can get pretty cold in my experience.


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## o1dschoo1

Asmodian said:


> If the A/C unit cools the intake air down at all, won't it be below ambient? It won't cool the room below ambient in that configuration, but it will cool the exhaust below ambient.
> 
> I have seen the exhaust from an A/C unit cool down metal objects in front of it low enough to condense water when exposed to ambient air. It is pretty common for the outside of the box to condense if you trap the exhaust somewhere. The exhaust can get pretty cold in my experience.


This was exactly what i meant. And the temp of the ambient air around his rad isnt what hes worried about. The temp around the tubing in his pc is. Thats where condensation is gonna matter. If the water temp drops below dew point its gonna condensate.
@op you are gonna have to monitor water temps


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## Slaughtahouse

Asmodian said:


> If the A/C unit cools the intake air down at all, won't it be below ambient? It won't cool the room below ambient in that configuration, but it will cool the exhaust below ambient.
> 
> I have seen the exhaust from an A/C unit cool down metal objects in front of it low enough to condense water when exposed to ambient air. It is pretty common for the outside of the box to condense if you trap the exhaust somewhere. The exhaust can get pretty cold in my experience.


You’re probably correct as I simply don’t know what is the temp of the cold air being exhausted from the unit. If its like 20c lower than the intake air, of course you will quickly run into issues. As the A/C is technically trying to lower the ambient of the room (intake).

Has anyone measured what temperature that air (typically) is?


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## o1dschoo1

Slaughtahouse said:


> You’re probably correct as I simply don’t know what is the cold temperature being exhausted from the unit. If its like 20c lower than the intake air, of course you will quickly run into issues. As the A/C is technically trying to lower the ambient of the room (intake).
> 
> Has anyone measured what temperature that air (typically) is?


Ok so i have a window unit taken apart to build a chiller. My ambient in my room is normally 70-72 with my main unit cooling the room. I put the thermostat in the vent to see how cold the air was getting and the thermostat on the unit dropped 15 degrees very quickly. I had the unit set on 65 and it went below that i couldn't exactly measure how far as i dont have a laser thermometer but the acs thermostat showed roughly 60 degrees when the compressor kicked off and it was still trying to drop.

Ik with a water chiller made with a 7k btu unit you can get water temps around -30c so id believe the air coming out is well below ambient


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## xH2L

Thank you for all the responses!

My idea was to use the A/C unit to drop the temps as close to ambient without getting to ambient or lower. As far as efficiency, it wouldn't exactly be a priority since this wouldn't be a daily driver kind of thing. It would just be used during the 3-5 minutes of benchmarking, depending on what I'm using to benchmark at the time. And at this point, with all the good points and information posted here, I feel like I could probably just run the A/C unit so that it is blasting cold air into the intake fans on the rad, and that may allow me some amount of drop in coolant temp, but most likely wouldn't approach ambient so I wouldn't need to worry too much about condensation. So I guess the question at that point would be, would the drop in coolant temp allow me to push the processor another few hundred megs. I would need to first see how far I can push the processor without the aid of the A/C unit.


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## o1dschoo1

xH2L said:


> Thank you for all the responses!
> 
> My idea was to use the A/C unit to drop the temps as close to ambient without getting to ambient or lower. As far as efficiency, it wouldn't exactly be a priority since this wouldn't be a daily driver kind of thing. It would just be used during the 3-5 minutes of benchmarking, depending on what I'm using to benchmark at the time. And at this point, with all the good points and information posted here, I feel like I could probably just run the A/C unit so that it is blasting cold air into the intake fans on the rad, and that may allow me some amount of drop in coolant temp, but most likely wouldn't approach ambient so I wouldn't need to worry too much about condensation. So I guess the question at that point would be, would the drop in coolant temp allow me to push the processor another few hundred megs. I would need to first see how far I can push the processor without the aid of the A/C unit.


Possibly. Your gonna need a 30c temp drop on your processor roughly as voltage is gonna scale horribly depending on how close you are to the limit. Remember colder the chip better it clocks.
Honestly ambient overclocking you wont really notice too much of a difference. When you get down to -20/30c is when it starts to get interesting


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## Formula383

Just put the whole pc in a box that is connected to your AC that blows through the box into the room, the air coming out of the AC has no chance of condensing water as the coldest point was the evaporator just before it go's out. so long as that outlet for the AC is taped up good your pc is safe!

edit: to be on the safe side run the pc for awhile after the ac is turned off to warm it back up to room temps. (also when your turn off the AC you want to turn off the fan on the AC as well at least for a few min until the pc has warmed up a fair bit.)


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## o1dschoo1

Formula383 said:


> Just put the whole pc in a box that is connected to your AC that blows through the box into the room, the air coming out of the AC has no chance of condensing water as the coldest point was the evaporator just before it go's out. so long as that outlet for the AC is taped up good your pc is safe!


This a chiller box is the way to go.


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## o1dschoo1

Formula383 said:


> Just put the whole pc in a box that is connected to your AC that blows through the box into the room, the air coming out of the AC has no chance of condensing water as the coldest point was the evaporator just before it go's out. so long as that outlet for the AC is taped up good your pc is safe!
> 
> edit: to be on the safe side run the pc for awhile after the ac is turned off to warm it back up to room temps. (also when your turn off the AC you want to turn off the fan on the AC as well at least for a few min until the pc has warmed up a fair bit.)


Actually you are gonna want to slowly raise the temp in the chiller box to ambient so it doesnt condensate. Turning the ac off and leaving the pc on would flash the temperature pretty quick.


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## Formula383

o1dschoo1 said:


> Actually you are gonna want to slowly raise the temp in the chiller box to ambient so it doesnt condensate. Turning the ac off and leaving the pc on would flash the temperature pretty quick.


ya i was thinking about this too, might be better to just turn off the pc and ac at the same time and let it sit.


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## Formula383

o1dschoo1 said:


> Actually you are gonna want to slowly raise the temp in the chiller box to ambient so it doesnt condensate. Turning the ac off and leaving the pc on would flash the temperature pretty quick.


But should that matter? so long as the pc is hot spot would that not help? note i am talking about leaving the pc in the cool box and just letting it run with no airflow. i mean the pc fans could still be spinning but not the box air it self. The air inside the box if stagnant should be very dry, that's what AC units do is remove the moisture.


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## o1dschoo1

Formula383 said:


> ya i was thinking about this too, might be better to just turn off the pc and ac at the same time and let it sit.


Thats the route id go honestly. If it condensates at that point theres no power going through it so its fine. Clean boards up and bam go back at it


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## o1dschoo1

Formula383 said:


> But should that matter? so long as the pc is hot spot would that not help? note i am talking about leaving the pc in the cool box and just letting it run with no airflow. i mean the pc fans could still be spinning but not the box air it self.


Yea think about it couple hundred watta of heat with active chilling to no cool air will actually flash fairly quick. My pc raises my room temps a few degrees and that's with a ac unit in the room. Gtx 1080 with a ln2 bios on it 2100 mhz and a 5ghz 7800x pushing probably 250-300w on its on. Gotta remember heat has to go somewhere. If you could raise the room temp and water temp at the same rate to where they are equalized then sure but that all depends on fluid used. Imma assume glycol/acetone mix


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## xH2L

I realize going subzero for overclocking is the ideal scenario, but I just don't have the money or equipment to do it. This is the next best thing for me, even if it's a little janky and doesn't net that much more overclocking headroom.


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## o1dschoo1

xH2L said:


> I realize going subzero for overclocking is the ideal scenario, but I just don't have the money or equipment to do it. This is the next best thing for me, even if it's a little janky and doesn't net that much more overclocking headroom.


I can show you a cheap way to do it for under 200 bucks


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## o1dschoo1

https://forums.evga.com/DIY-low-cost-subzero-chiller-for-benchmarking-m2951571.aspx


Read this thread. I already got a ac unit apart ready to do a chiller just debating on if i wanna go chiller route or find someone to build me a phase head for cpu only cooling. Decisions decisions.
The difference at around ambient is only 100 mhz on cpu roughly. Just allow you to bump the voltage more but is still risky to hardware as the further you go below 0c the more the atoms line up and help negate electromigration


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## Cerberus

shoot, I built a single stage phase unit that did -40c on a 955BE in 2009, cost was close to a 10kbtu window unit, so cost Isnt really a major factor, heck, you could build one for a rtx3080 price nowadays. I covered the whole board in blu tack, die-electric grease in the socket, ran that way for close to two years constantly running. When I did eventually take it apart, about 15 pins were corroded off the cpu


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## o1dschoo1

Cerberus said:


> shoot, I built a single stage phase unit that did -40c on a 955BE in 2009, cost was close to a 10kbtu window unit, so cost Isnt really a major factor, heck, you could build one for a rtx3080 price nowadays. I covered the whole board in blu tack, die-electric grease in the socket, ran that way for close to two years constantly running. When I did eventually take it apart, about 15 pins were corroded off the cpu


so theres no way to stop pin rot


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## Cerberus

o1dschoo1 said:


> so theres no way to stop pin rot


for anything longer than a year, i'd say no


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## Luggage

Get a humidity sensor.


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## o1dschoo1

Cerberus said:


> for anything longer than a year, i'd say no


Just for off and on bench runs tbh about a day at a time on weekends. I shouldnt have to worry bout it or pull the cpu right


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## Slaughtahouse

o1dschoo1 said:


> Thats the route id go honestly. If it condensates at that point theres no power going through it so its fine. Clean boards up and bam go back at it


I ran my PC out in the winter before (-10c?). Threw it out the window and ran the cables through.

When it was time to bring the PC back into the indoor environment, I simply left it off for a few hours, case panel open, and put a fan close by.

If there was condensation, it likely appeared within a few seconds from when the PC was introduced into the indoor environment. However, I remember it drying pretty quickly. 

Never had an issue but also never did it again 

Link to thread/photos









[Build Log] M1 Abrams


Hey, I've been apart of the community for almost a year now and I've decided to start a log for my build. The goal of this build is to have a gaming and CAD rig all in one. I've already begun building this pc for about 8 months now but instead of just filling up the C70 case thread, I'll keep...




www.overclock.net


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## Slaughtahouse

Formula383 said:


> But should that matter? so long as the pc is hot spot would that not help? note i am talking about leaving the pc in the cool box and just letting it run with no airflow. i mean the pc fans could still be spinning but not the box air it self. The air inside the box if stagnant should be very dry, that's what AC units do is remove the moisture.


A/C units remove, or better stated from another user, move heat.

In that process, yes water will be removed but its more of a byproduct of the reduction in heat. As humidity is relative (RH). The higher the air temperature, the more quantity of water can be retained. 70% RH at 28C = more water content than 70% RH at 21C.

I had a very interesting building science teacher explain the process to me from a building/construction view. Think of air as a sponge. As it gets hotter, the size of the sponge increases.

As it gets colder, the size decreases. If it gets cold quickly, it’s effectively ringing out the sponge and thats your condensation 

If you want to control humidity more efficiently without modifying temperature, you’ll need a humidifer or dehumidifier.

Having too high or low humidity long term also presents other challenges in PC environment. Too low, you could promote static discharge. Too high, you may introduce corrosion on certain metal finishes.

I only know the above because I have experience in building mission critical/ server rooms. Humidity has to be within a certain range to avoid damage to IT equipment.


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## Gattlin

Skip to the end of the images gallery


























































Skip to the beginning of the images gallery
*iPower 4 Inch 13- CFM Inline Duct Fan with Speed Humidity Temperature Controller for Grow Tent Ventilation, 4", Black*


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## Gattlin

Pondered this myself $80 then shipping hmm it does have possibilities


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## Logic11

The easiest way to avoid going below the dew point; always, for certain, cheaply
is evaporative cooling.

Reqd:
External rad.
Ultrasonic mist maker/s mist going onto/through rad.
Your fans will be fine thx to centrifugal force...

You need to get the humid air out the room and/or fresh/dry air in/through the rad, or it will become saturated with humidity and then evaporation stops...

It's much cheaper than throwing electricity and expensive cooling/chiller hardware at the 'below ambient cooling' challenge.


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## jrba

xH2L said:


> In order to avoid condensation, is it as simple as making sure the coolant temperature doesn't drop below the ambient temperature? I'm curious because I'd like to create a shroud, or cold-box, to place around my mora, and see if I can drop temps to near-ambient during overclocking, using a standing A/C unit that I have. Though I'm not entirely sure it will prevent condensation all together, because only the mora would be placed in the cold-box, and not the rest of my bench setup. Which means fittings and cpu/gpu blocks would be exposed to higher ambient temperatures than what would be inside the cold-box, right?


 why don’t you just setup rad outside of box and cool it with ac in its on enclosure. Then condensation doesn’t matter just have something to catch it.


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## o1dschoo1

Logic11 said:


> The easiest way to avoid going below the dew point; always, for certain, cheaply
> is evaporative cooling.
> 
> Reqd:
> External rad.
> Ultrasonic mist maker/s mist going onto/through rad.
> Your fans will be fine thx to centrifugal force...
> 
> You need to get the humid air out the room and/or fresh/dry air in/through the rad, or it will become saturated with humidity and then evaporation stops...
> 
> It's much cheaper than throwing electricity and expensive cooling/chiller hardware at the 'below ambient cooling' challenge.


No you absolutely do.... You will absolutely never go below ambient temperature without somekind of phase change


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## Luggage

o1dschoo1 said:


> No you absolutely do.... You will absolutely never go below ambient temperature without somekind of phase change


Evaporerative cooling can get you under ambient, look at the bong cooler thread.

Not so sure if it can get you under dew point.

(Evap is phase change though…)


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## o1dschoo1

Luggage said:


> Evaporerative cooling can get you under ambient, look at the bong cooler thread.
> 
> Not so sure if it can get you under dew point.
> 
> (Evap is phase change though…)


Well technically yes but no it wont go under dew point its crazy big inefficient and honestly not worth.


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## Logic11

o1dschoo1 said:


> No you absolutely do.... You will absolutely never go below ambient temperature without somekind of phase change



Remember the old 'Bong Cooler' days?

Here's a fellow cooling a TEC, cooling a CPU OCd to 1580 MHz! 


Idle: -14C
Load: 4C
Coolant 4C below ambient in reservoir.






Nuclear Tower Water Cooling - Overclockers


ED NOTE: This article is 5 pages long. Those of you running peltier cooled T-Bird rigs are probably aware that you are pushing the limits of standard water cooling methods. Many vendors claim their coolers are capable of “handling” several




www.overclockers.com





So yes; below ambient IS possible with evaporative cooling.

So:




6 mins in
Through a rad..?
(To avoid the whole: Algae build-up and no cooling when all the water's evaporated thing..?

Soz; I'm derailing tread here


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## o1dschoo1

Logic11 said:


> Remember the old 'Bong Cooler' days?
> 
> Here's a fellow cooling a TEC, cooling a CPU OCd to 1580 MHz!
> 
> 
> Idle: -14C
> Load: 4C
> Coolant 4C below ambient in reservoir.
> 
> 
> 
> 
> 
> 
> Nuclear Tower Water Cooling - Overclockers
> 
> 
> ED NOTE: This article is 5 pages long. Those of you running peltier cooled T-Bird rigs are probably aware that you are pushing the limits of standard water cooling methods. Many vendors claim their coolers are capable of “handling” several
> 
> 
> 
> 
> www.overclockers.com
> 
> 
> 
> 
> 
> So yes; below ambient IS possible with evaporative cooling.
> 
> So:
> 
> 
> 
> 
> 6 mins in
> Through a rad..?
> (To avoid the whole: Algae build-up and no cooling when all the water's evaporated thing..?
> 
> Soz; I'm derailing tread here


I mean technically you are lowering the ambient in the bong cooler which cools pc. So it is ambient technically.


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## Logic11

o1dschoo1 said:


> I mean technically you are lowering the ambient in the bong cooler which cools pc. So it is ambient technically.


ah... 
Er... no; below ambient of the room would be 'Sub Ambient' in any argument IMHO.

But point is:
With a 100% efficient Evap Cooler; you just cant ever go below the dew point as that's the point at which water vapour in the air starts condensing out.. NOT evaporating into the air...

And much cheaper than refrigeration tech and dew point sensors etc.


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## o1dschoo1

Logic11 said:


> ah...
> Er... no; below ambient of the room would be 'Sub Ambient' in any argument IMHO.
> 
> But point is:
> With a 100% efficient Evap Cooler; you just cant ever go below the dew point as that's the point at which water vapour in the air starts condensing out.. NOT evaporating into the air...
> 
> And much cheaper than refrigeration tech and dew point sensors etc.


I really beed to stay off of here early in the am lol. Tf was i thinking.


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## Ballistic308

Won’t the AC unit will also remove moisture from the air? Most do anyway…


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## Asmodian

Ballistic308 said:


> Won’t the AC unit will also remove moisture from the air? Most do anyway…


The problem with relying on that effect is that if you turn off the AC or some non-AC air gets in water will condense on everything cold until it gets above the dew point.

You don't get puddles, but that does not mean it is safe.


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## Ballistic308

Perhaps set it low enough such that it doesn’t turn off while the PC is in use. Just thinking out loud is all.


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## Asmodian

It will still condense all over everything as soon as you turn it off, even if the system is off it is not good having water condense on it.


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## storm-chaser

Use a box fan and put the computer outside when you want to bench (winter months). That way you will be mitigating the condensation on two different fronts.


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## Carlyle2020

I currently test a selfmade tec gpu backplate for next gen with a 3080ti.

I circumvent condensation issues by using a weak tec that i turn on on 5 minutes after i start gaming and turn it off 3 minutes before i stop.

Like a 120watt colling boost during gaming without the chance of condensation - IF done according to plan.










The issue i have is that i want to fully fill the gap between gpu backplate and pcb with thermal putty that does not sweat out so much silicone that it leaves tiny air filled bubbles in the putty afterwards.

Any suggestions other than that "painters cleaning putty". That is only good for insulation. I need heat transfer as well.

K5-pro (new formula) is what i currently use. 

Does anybody know another testworthy thermal putty?


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