Can someone explain to me why an AIO cooler has evaporation issues, but a heatsink on a gpu or cpu does not?

[Space Lynx]

a gpu vapor chamber or say... even an air heatsink for cpu with the piping in it. pretty sure a noctua dh-15 has liquid in it/vapor that moves through the pipes as it gets heated to distribute the heat to the fins ya?

if that is the case then why do AIO's evaporate? is it as simply as metal enclosure doesn't allow for evaporation? if it is then i am sorry for asking a dumb question.

most radiators on AIO's are metal, so im surprised they can't do a thin coat of flexible aluminum on the tubing to prevent evaporation if this is the case... or what am I missing here?

 

[freeagent]

s it as simply as metal enclosure doesn't allow for evaporation?

Yes, plastic is porous, metal is not.

 

[GerKNG]

it's not evaporation. It's permeation and is in a normal AIO in the low single digit ml rate per year. But it accelerates a lot if the liquid temperature rises above 50-60°C.

 

[freeagent]

The hotter the heat load, and the warmer the ambient, the rate of permeation will be higher than normal. But that really depends on many, many factors. A lot of people can run theirs for years and claim no problems.. I believe it. Those machines are internet cruisers and video watchers. But if you run f@h, wcg, or anything that most normal people don’t run, I think I would pass.

 

[Vya Domus]

Both AIOs and vapor chambers/heatpipes will eventually lose some of the liquid via permeation.

 

[Arco]

The hotter the heat load, and the warmer the ambient, the rate of permeation will be higher than normal. But that really depends on many, many factors. A lot of people can run theirs for years and claim no problems.. I believe it. Those machines are internet cruisers and video watchers. But if you run f@h, wcg, or anything that most normal people don’t run, I think I would pass.

Yeah, the coolers are stupid big. You would have to run stress tests for hours to really hurt anything.

 

[Space Lynx]

Both AIOs and vapor chambers/heatpipes will eventually lose some of the liquid via permeation.

ok thank you for saying this, my next question was going to be why not just line the tubing on AIO's with aluminum or some kind of other flexible metal, but in the end I guess it doesn't matter.

 

[GerKNG]

my next question was going to be why not just line the tubing on AIO's with aluminum or some kind of other flexible metal, but in the end I guess it doesn't matter.

many AIOs have PTFE (Teflon) tubing to reduce permeation to almost zero.

 

[Space Lynx]

many AIOs have PTFE (Teflon) tubing to reduce permeation to almost zero.

I did not know this, thanks.

 

[Vya Domus]

ok thank you for saying this, my next question was going to be why not just line the tubing on AIO's with aluminum or some kind of other flexible metal, but in the end I guess it doesn't matter.

I mean obviously permeation is much slower in mentals than plastic, also in vapor chambers the permeation occurs when the liquid turns in vapor. I guess corrosion would be the main problem, I also don't know if a thin coating would make any real difference either not to mention it would rise the manufacturing costs/complexity.

 

[freeagent]

many AIOs have PTFE (Teflon) tubing to reduce permeation to almost zero.

That’s probably what the black gunk is that collects in the cold plate..

 

[Bill_Bright]

I have a hard time believing this has anything to do with permeation. In fact, I don't believe it is, and here's why.

Permeation certainly exists. No denying that. Smaller atoms/molecules can slip through the open spaces between larger atoms/molecules just like dust particles (and friggin' noseeums ) can sneak through window screens.

But it is not hard (or expensive) to formulate the plastics used in these coolers to greatly reduce or even totally block permeation. They typically just add a small amount of some type of fluorinated chemical or polymer to the mix and abracadabra - done! Those big empty spaces between the plastic atoms/molecules are filled in with coolant blocking molecules.

Remember, very caustic stuff like bleach, ammonia, even lye drain opener is stored for years and years in inexpensive plastic containers. Those liquids don't leak, evaporate, "eat" or permeate through the plastic. The casings of car batteries are made of plastic.

If these AiO coolers were using plastics that worked like a sieve, millions of AiO users would be complaining and more importantly NOT BUYING them! And even more importantly still, telling all their friends not to buy them either.

So NO. It is NOT "permeation" - at least not with any name brand AiO cooler by a reputable maker. If you are losing coolant, it is due to a defect/leakage, perhaps through a tiny microfracture in the block or a hose. But I suspect it more likely to be through a poorly sealed fitting - and it is likely to be such a tiny leak to be nearly invisible and never drips. Instead, as soon as the tiny droplet of coolant is exposed to the air, it quickly evaporates and thus is never seen again. But eventually, those tiny droplets add up to a tiny milliliter, then 2mL, then 10mL and so on.

 

[freeagent]

So NO. It is NOT "permeation" - at least not with any name brand AiO cooler by a reputable maker.

I have a very light Corsair H100 that says hi

 

[Bill_Bright]

A one-off anecdotal exception does not make the rule. Surely Corsair uses the same hose materials on many, if not all their AiO coolers. If permeation was a problem, this would be BIG news throughout the industry, repair shops and tech forums.

I note too, many of the big factory computer makers like Dell and HP sell computers with AiOs. Those makers would not tolerate (or buy) those products if permeation was such a problem.

I stand by my assertions. If these coolers are losing coolant, it is due to some manufacturing defect or after-sell damage/abuse and not due to permeation through the plastic hoses.

 

[cvaldes]

many AIOs have PTFE (Teflon) tubing to reduce permeation to almost zero.

It should be noted that PTFE is not a very sturdy material. If you own PTFE coated cookware, you'd understand; the pans last 5-10 years even with careful usage.

Also if you've handled PTFE tape (for plumbing), you'd also note that can be easily torn. While it might provide a good vapor barrier when initially applied, the twisting and kinking of AIO radiator tubing will eventually cause cracks which ends up in permeation. The PTFE will slow down permeation but not eliminate it in real world applications when the coated surface is moved around (like AIO tubing).

PTFE tape for plumbing tends to last a long time because it is immobile.

 

[Frag_Maniac]

many AIOs have PTFE (Teflon) tubing to reduce permeation to almost zero.

People talk about permeation as if it's entirely different from evaporation, but the reality is, the worry about permeation is because when coolant permeates the tubes, it then evaporates, so the end goal is still to minimize evaporation by any means.

I also have to wonder about whether Teflon tubing is the be all end all of permeation solutions, because Arctic Cooling just uses thick, fiber reinforced rubber lined with nylon, and their AIO's have 6 yr warranties and are rated as some of the best performing, and longest lasting on the market.

So I have to think there's more than one way to effectively skin the evaporation cat.

 

[Bill_Bright]

While it might provide a good vapor barrier when initially applied, the twisting and kinking of AIO radiator tubing will eventually cause cracks which ends up in permeation.

Ummm, kinda, sorta, but not really. You are 100% correct to say that over time, due to handling as well as constant expansion and contraction during heat/cool cycles, cracks may eventually form. But permeation is NOT the result of coolant escaping through cracks. Those are just leaks through cracks. A broken pipe.

Permeation is smaller atoms moving through the spaces between larger atoms of solid materials at the molecular level. A "crack" formed over time by twisting, kinking, expansion/contraction would be "Grand Canyon" size openings (microscopically speaking) in that otherwise solid material.

 

[cvaldes]

So I have to think there's more than one way to effectively skin the evaporation cat.

There are a wide range of materials available for hosing. They aren't all the same.

As always, there are multiple factors that influence selection: ease of manufacturing, durability, maintenance, toxicity, recyclability, and of course cost. One company may choose a better material that increases COGS. Another company might pick a cheaper material knowing it won't last as long.

Since Joe Consumer isn't a materials chemist (and the manufacturers won't go into detail about the actual material anyhow), we are all forced to make up our own minds on the value proposition of each model, the manufacturers' claims, and ultimately the manufacturers' reputations.

I have cheap AIOs and nicer ones (like the aforementioned Arctic Liquid Freezer) just like I have cheap kitchen utensils and nicer ones, cheap shoes and nice shoes.

For sure evaporation in AIO closed loop coolers is exacerbated by higher temperatures so one way to mitigate this problem is to pick the right sized unit so the coolant isn't constantly running at an excessively high temperature, thus shortening the lifespan of the device. More powerful CPU? Use a larger radiator.

These are all decisions that need to be made by each builder. Some people might be fine with a cheap AIO that they plan to replace in three years because they'll be upgrading their entire platform in that timeframe.

 

[Frag_Maniac]

There are a wide range of materials available for hosing. They aren't all the same.

As always, there are multiple factors that influence selection: ease of manufacturing, durability, maintenance, toxicity, recyclability, and of course cost. One company may choose a better material that increases COGS. Another company might pick a cheaper material knowing it won't last as long.

Since Joe Consumer isn't a materials chemist (and the manufacturers won't go into detail about the actual material anyhow), we are all forced to make up our own minds on the value proposition of each model, the manufacturers' claims, and ultimately the manufacturers' reputations.

I have cheap AIOs and nicer ones (like the aforementioned Arctic Liquid Freezer) just like I have cheap kitchen utensils and nicer ones, cheap shoes and nice shoes.

For sure evaporation in AIO closed loop coolers is exacerbated by higher temperatures so one way to mitigate this problem is to pick the right sized unit so the coolant isn't constantly running at an excessively high temperature, thus shortening the lifespan of the device. More powerful CPU? Use a larger radiator.

These are all decisions that need to be made by each builder. Some people might be fine with a cheap AIO that they plan to replace in three years because they'll be upgrading their entire platform in that timeframe.

Well, I think it's best to weed out extremely high and low expectations, as well as the relatively uneducated whom don't research such products or TDP/RAD size well. What I feel it then comes down to is fairly simple, once you pick the right RAD config for your CPU, look at trusted sites that do in depth reviews, like GamersNexus, and it becomes more obvious that things like thicker RADs (which other manufacturers are adopting and considering after Arctic Cooling did it), as well as an industry leading warranty, and the choice becomes clear for me.

I mean $125 for the Liquid Freezer II 360 is a steal compared to what many are charging for these things. Obviously stock is affecting price on the non RGB units right now, because so many are falling for the rainbow crap, but Arctic are telling me they're still making the non RGB ones.

 

[cvaldes]

I mean $125 for the Liquid Freezer II 360 is a steal compared to what many are charging for these things. Obviously stock is affecting price on the non RGB units right now, because so many are falling for the rainbow crap, but Arctic are telling me they're still making the non RGB ones.

I recently picked up the Arctic Liquid Freezer II 240 non-RGB so yes, they are still selling them.

For sure, Arctic has their manufacturing partner make batches at a time, they don't roll off some manufacturing line one by one as orders come in. So any absence of non-RGB units in the marketspace is simply a lull between batches. The non-RGB models are probably in lower demand these days so Arctic probably isn't pressed to order a new batch from their manufacturing partner.

One thing I did note was that lower-priced B stock units from the Arctic eBay store were out of stock. I ended up buying a brand new one on sale from Amazon which was competitively priced with what the B stock units normally go for. But I looked for B stock availability first.

If you get an extra year or two of usage and a better performing unit, it's probably worth spending an hour or two doing a little research (reading reviews, comparing prices, thinking about your usage case and value expectations).

Again, people do this will all purchases, not just consumer PC components. I might spend 5-10 seconds deciding between two bags of flour at the grocery store but the same thought process is essentially happening.

I definitely spend more time with real estate purchases.

 

[freeagent]

I stand by my assertions

Just because you don’t understand how it can happen doesn’t mean it doesn’t happen. I had no leaks or wet spots anywhere. The only change I made was different fans.

I know for a fact that I am not the only one this has happened to.

 

[oxrufiioxo]

Just because you don’t understand how it can happen doesn’t mean it doesn’t happen. I had no leaks or wet spots anywhere. The only change I made was different fans.

I know for a fact that I am not the only one this has happened to.

I still think in probably 99% of scenarios the pump is more likely to die than the cooler having issue from permeation I still have AIO going strong that are 10 years old again small sample size that really doesn't matter a whole lot..... Good rule of thumb with AIO buy one with a long warranty 5-6 years beyond that just buy a new cooler if it fails.

If that isn't appealing buy an air cooler.

 

[Arco]

Arctic's AIO lineup is the best for sure. I'm glad I went that route.

 

[oxrufiioxo]

Arctic's AIO lineup is the best for sure. I'm glad I went that route.

whenever they decide to make them less fugly I'll probably will pick one up. I don't really care if it cost 30-40 usd more just to not look so terrible.

 

[Frag_Maniac]

whenever they decide to make them less fugly I'll probably will pick one up. I don't really care if it cost 30-40 usd more just to not look so terrible.

I happen to think their base ones are the best looking units on the market, but then I factor in performance and practicality, so things like including a VRM fan in the pump head, and neatly tucking the power wires into the tubing matter to me. It's the unnecessary fashion show stuff like RGB I find off putting. It's like expecting your cooler to double as a unicorn for God's sake!

With things like RGB though, they're just responding to silly user requests, so I can't blame them for that.