Loop Pressure / Temperature

[cluelessgenius]

hey guys,

 

so im planning this build and since this is my first time going full custom watercooling i got a couple of topics im not sure about and i thought maybe you could help clarify.

 

first off i found it weird that PETG tubing (or any tubing actually) seems to be rated only up to 60°C. i have never messured the coolant before but since i know the hardware cn get hotter than that easily i would assume so whould the coolant but since everyones build seems to be fine i guess it doesnt matter. just found it weird.

 

secondly and more importantly pressure: since the coolant gets hotter and colder the coolant and air will compress and expand raising and decreasing the pressure inside the loop. alphacool for this purpose sell a membran that allow the pressure between the loop and the environment to equalize without letting out water itself. this all makes sense to me but then again closed loop units dont have that so do i need it?

 

lookinng forward to reading your opinions on this 

 

[Oshino Shinobu]

1. The fluid in the loop normally doesn't get too hot. Your components would overheat and shut the system down before your fluid got hot enough to reach the tubing's limits. 

 

2. Don't need it. AIOs and custom loops have been running fine for years without that. 

[Dissitesuxba11s]

15 minutes ago, cluelessgenius said:

secondly

Because the coolant's change in temperature (delta T) will not change that drastically over short periods of time, you will not see significant changes in pressure that will affect cooling performance or loop longevity. At least that is my understanding of the physics of watercooling.  

[cluelessgenius]

38 minutes ago, Oshino Shinobu said:

1. The fluid in the loop normally doesn't get too hot. Your components would overheat and shut the system down before your fluid got hot enough to reach the tubing's limits. 

 

2. Don't need it. AIOs and custom loops have been running fine for years without that. 

 

26 minutes ago, Dissitesuxba11s said:

Because the coolant's change in temperature (delta T) will not change that drastically over short periods of time, you will not see significant changes in pressure that will affect cooling performance or loop longevity. At least that is my understanding of the physics of watercooling.  

thanks

 

i just remembered one other thing : what about condensation i saw a couple of loops that started to build up condensation when hot. is that a given? can i do something to prevent that ? 

[Oshino Shinobu]

Just now, cluelessgenius said:

 

thanks

 

i just remembered one other thing : what about condensation i saw a couple of loops that started to build up condensation when hot. is that a given? can i do something to prevent that ? 

It can happen if you have a portion of air in the top of the reservoir from what I've seen. Just filling the loop so it's always full seems to stop it. I've never had condensation in my loop though, so I can't really say for sure. 

[Dissitesuxba11s]

1 minute ago, cluelessgenius said:

condensation

I think that just occurs naturally since it happened on mine too. That is due to the slight temperature difference between room and loop, similar to condensation in your car.

[Greg2895]

From my experience with petg I have only had one issue. My fan controller failed, shutting off all of my fans while I was gaming. The coolant temp was able to rise hot enough before my gpus throttled causing leaks at some of the fittings. When petg heats up it becomes soft very quickly and the compression fittings then squeeze the pipe and it will leak. I have had petg loops for years and don’t plan on changing anytime soon. 

[For Science!]

Coolant temps are typically in the 30~45 degree range, even though your components may be hotter. Your standard pump such as the D5/DDC are rated for operation up to 60 degrees anyway, so if your coolant was approaching these temperatures, your pump is most likely to suffer first.

 

I've washed my radiators with PETG attached under incredibly hot tap water (i.e. too hot to touch) and they have not deformed in my hands, so perhaps there are some variability depending on the brand? (this was EK stuff).