Fan-less Liquid Cooling?

[Me1z]

From what I've seen, most liquid cooling loops are designed with a dependency on noisy fans to cool the radiators. Theoretically of course, if you had a enough radiators or a large enough reservoir could you have all the heat passively dissipate with no cool down period? I suppose the real question I'm getting at is; what is the ratio between radiator/reservoir space and potential passive heat dissipation?

 

For some context, I happen to be a pretty avid folder and have a dedicated folding rig that throws off quite a bit of heat. Now, if everything goes according to plan I will be going away to college next semester rather than staying at home, and that means I'm technically no longer responsible for my personal power consumption. This and for basic maintenance purposes, I'd ideally like to bring my folding rig with me. The first issue that I'm finding is noise, because pissing off my roommates with noisy computers is bound to draw unwanted attention, and I think minimal fan usage is a good solution. I'll be going to school in the north-eastern US so heat build up in the room isn't too much of an issue. The average winter day is 20 below 0 there so if anyone complains I could just open a window. Again, this is all just theoretical at this point, there's a bunch of options that I'm toying with, I just figure this would be a best case scenario.

[TheKDub]

You'd probably need a pretty damn large radiator to cool it decently without fans.

 

I live in the north-eastern USA (Michigan), and let me tell you this, it gets pretty warm up here in the summer, usually high 70s to low-mid 90s depending on the day... (Even worse when you live in the upper floor and your parents refuse to turn the AC on...)

[EthanMcL]

Following the main point, I don't quite know what the answer would be.

 

For the context: Get quieter fans!  Really you shouldn't have much of a problem with some good quality fans cooling everything.  Or a noise reducing case.

[squirrl]

The greater the surface area, the less fans/RPM you need.

I have 2 quad rads on a 4770k and a 780 and successfully ran the PC in some games without the fans being plugged in for a week while i was doing stuff with my fan controller. Got hotter than usual as you would expect, but it worked fine since the heat was spread over a larger area and the passive air was doinig some of the cooling.

So yes, you can have fanless liquid cooling.

It's been a while since i used that pc, but i think i have the fans turned off when the temperature is below a certain point too, so it only turns on when under load in games when you won't really hear it.

[flibberdipper]

You'd probably need a pretty damn large radiator to cool it decently without fans.

 

I live in the north-eastern USA (Michigan), and let me tell you this, it gets pretty warm up here in the summer, usually high 70s to low-mid 90s depending on the day... (Even worse when you live in the upper floor and your parents refuse to turn the AC on...)

Dude... It was 80 where I was today. Between installing things on my weekend rig, stressing it, and then benching it all while doing things like gaming, YT, and now video editing on my main rig... My room was probably close to 95-100. With the fan in my window. Sucking air in. At full speed.

[TheAmazingCookieFromSquare]

Well maybe a single 580mm rad thats 80mm think would do the trick

[TheKDub]

Dude... It was 80 where I was today. Between installing things on my weekend rig, stressing it, and then benching it all while doing things like gaming, YT, and now video editing on my main rig... My room was probably close to 95-100. With the fan in my window. Sucking air in. At full speed.

 

It was about 80 here today too, I've not done much intensive on my rig except for gaming

I've got a fan in my window too, running at half speed sucking air out cause its humid as fuck outside

[flibberdipper]

It was about 80 here today too, I've not done much intensive on my rig except for gaming

I've got a fan in my window too, running at half speed sucking air out cause its humid as fuck outside

Damned Michigan. Apparently moving down south to Kentucky is becoming more and more realistic every day. My dad is on a two year plan to get down there (so hopefully I can graduate).

[Kyuubixchidori]

You'd probably need a pretty damn large radiator to cool it decently without fans.

 

I live in the north-eastern USA (Michigan), and let me tell you this, it gets pretty warm up here in the summer, usually high 70s to low-mid 90s depending on the day... (Even worse when you live in the upper floor and your parents refuse to turn the AC on...)

 

Dude... It was 80 where I was today. Between installing things on my weekend rig, stressing it, and then benching it all while doing things like gaming, YT, and now video editing on my main rig... My room was probably close to 95-100. With the fan in my window. Sucking air in. At full speed.

Always run into the fellow mich people. today was hot as hell, and I was outside doing camping stuff, not silly computer stuff. 

 

that being said, switching from a I5 at 4.4ghz+2 7970s at 1.25 volts each to a xeon and a 750ti, I went from a stupid hot room to a room that I wouldnt notice if my PC was maxxed out all day.

 

OP, depends on parts. I know for my parts the fans never go over 15% besides GPU under load. idle? cpu is at 200 rpm, gpu is whatever the min is, and all other fans are off. so my parts are almost already passively cooled. 

[Me1z]

You'd probably need a pretty damn large radiator to cool it decently without fans.

 

I live in the north-eastern USA (Michigan), and let me tell you this, it gets pretty warm up here in the summer, usually high 70s to low-mid 90s depending on the day... (Even worse when you live in the upper floor and your parents refuse to turn the AC on...)

 

During the summers I would bring it home with me. I have no problem with it running in my basement for a few months out of the year, I've found that the constant heat output prevents it from feeling damp down there anyway.

 

The greater the surface area, the less fans/RPM you need.

I have 2 quad rads on a 4770k and a 780 and successfully ran the PC in some games without the fans being plugged in for a week while i was doing stuff with my fan controller. Got hotter than usual as you would expect, but it worked fine since the heat was spread over a larger area and the passive air was doinig some of the cooling.

So yes, you can have fanless liquid cooling.

It's been a while since i used that pc, but i think i have the fans turned off when the temperature is below a certain point too, so it only turns on when under load in games when you won't really hear it.

 

Alright, so if I were to get 2 quad rads and some very low rpm fans do you think it could effectively cool 4 high-end GPUs? And by cool, all I'm looking for is sub 70 degree temperatures. It just has to perform as well as the stock cooler does without sounding like like a hairdryer.

[Me1z]

Always run into the fellow mich people. today was hot as hell, and I was outside doing camping stuff, not silly computer stuff. 

 

that being said, switching from a I5 at 4.4ghz+2 7970s at 1.25 volts each to a xeon and a 750ti, I went from a stupid hot room to a room that I wouldnt notice if my PC was maxxed out all day.

 

OP, depends on parts. I know for my parts the fans never go over 15% besides GPU under load. idle? cpu is at 200 rpm, gpu is whatever the min is, and all other fans are off. so my parts are almost already passively cooled. 

 

Lets say the heat output would be the same as 4 7970s and all I'm looking for is sub 70 degree temperatures under load. What would you recommend if you wanted to keep noise to a minimum? The CPUs don't get much action from folding so I'm not very concerned with them right now.

[FireofDestruction]

i live in FL you all are lucky it was like 89-92 in my room today(twas raining today) damned pc i really wanna switch to a 980(Ti crosses fingers) but any way passive cooling is possible just

 

going to take a lot of rads to do so, but if you had a good deal of rad space and quite a few fans you could theoretically run the fans at much lower speeds say like 200-500 rpm?  and still

 

get decent temps maybe... just maybe

[asquirrel]

From what I've seen, most liquid cooling loops are designed with a dependency on noisy fans to cool the radiators. Theoretically of course, if you had a enough radiators or a large enough reservoir could you have all the heat passively dissipate with no cool down period? I suppose the real question I'm getting at is; what is the ratio between radiator/reservoir space and potential passive heat dissipation?

 

For some context, I happen to be a pretty avid folder and have a dedicated folding rig that throws off quite a bit of heat. Now, if everything goes according to plan I will be going away to college next semester rather than staying at home, and that means I'm technically no longer responsible for my personal power consumption. This and for basic maintenance purposes, I'd ideally like to bring my folding rig with me. The first issue that I'm finding is noise, because pissing off my roommates with noisy computers is bound to draw unwanted attention, and I think minimal fan usage is a good solution. I'll be going to school in the north-eastern US so heat build up in the room isn't too much of an issue. The average winter day is 20 below 0 there so if anyone complains I could just open a window. Again, this is all just theoretical at this point, there's a bunch of options that I'm toying with, I just figure this would be a best case scenario.

...no. Not with current water cooling gear. To get passive radiative heat removal you'd need to go with mineral oil cooling. The reason why is that current water block + radiator technology requires the pump to move the water. The convection of the heated water is not sufficient to self-power the pumping action.

 

As for passively cooling radiators, the problem is their design. The designs of the radiators you would by from any water cooling company are *designed* with a fan in mind. They'd look different if they were designed to passively cool (specifically they would look like http://en.wikipedia.org/wiki/Cooling_tower a hyperboloid cooling tower). If noise is what you want to get rid of, it really isn't hard. Just have more radiators and run your fans at a lower RPM. 1000-1200 RPM on most 120mm and 140mm fans is considered silent or silent-enough. If you calculate (you did calculate how much rad you need...right...RIGHT?!) that you need a 280mm radiator with full-RPM fans to get the temperature delta you want, just buy a second radiator and run the fans at a lower speed. It won't be perfectly equivalent, but it will be good enough.

 

Making the pump silent can be a proper challenge. Some pumps are quiet enough and only need a shock absorbing mount. Others will need a sort of 'box' made around them with noise dampening foam (in this case, the box won't touch the pump, but rather encompass it, with an air inlet and outlet, so that the pump can be cooled, but still have sound dampening material between it and the case walls on all but the air-intake side).

 

edit: Here's an example of the sound dampening box I was talking about. On the bottom of the pump you could have the foam touching, or you could have something that allowed air to pass through; your call. The water out could be on either side of the pump without issue.

 

The reason the air outlet is behind and above the pump is that it forces sound waves to turn, which inherently robs them of some of their energy, making them quieter. The outlet gap will need to be wider than it appears in this photo to allow sufficient air to escape (you want no restriction on your outlet or intake), but you get the idea that it should be both behind and not-in-line with the pump itself.

[asquirrel]

Lets say the heat output would be the same as 4 7970s and all I'm looking for is sub 70 degree temperatures under load. What would you recommend if you wanted to keep noise to a minimum? The CPUs don't get much action from folding so I'm not very concerned with them right now.

Sorry, I should have read the entire thread before replying... anyway:

 

http://linustechtips.com/main/topic/332558-how-much-rads-for-cpu-gpu/?p=4534331

 

I have some posts in that thread regarding radiator sizing. Note that all the values I use assume 2,000 RPM fans (per the test data given). Also, those numbers are what is needed for a 10C delta, so...that's probably quite a lot more than you actually need, and a 20C or 30C delta is fine. Sadly, I'm not entirely sure what the math is on downsizing a rad for for higher delta. Sorry

[Stefan1024]

- snip -

I'd love to see this happen!

 

Of course you need a pump and therefor your build will not be completly fanless. But fanless rads are easy to make. You can't take normal rads because the finns are to close. You need a distance of ~10mm. Also it should be high (>200 mm) so a chimney effect can be build. What is your capability to DIY something?

 

Mount a heat exchanger like this

 

on a heat sink like this

 

Take 300mm long pieces (cost ~100$, weigth 9 kg) and you can dissipate 100 watts per 10 °C temperature rise.

(I use 3 of them with 400mm, look here http://linustechtips.com/main/topic/351134-the-silent-cube-pushing-passive-cooling-to-the-limit-with-dual-gtx-980-update-2-the-heat-sinks-are-delivered/)

[ThomasD]

Used to live in a small mountain town in northern Idaho.  In the winter our water bill was a flat rate (being minimally treated snow melt it was use it or lose it anyway.)  I often thought I could just hook up a waterblock to the tap and then run the exhaust back to the sink, but wasn't willing to swap systems every summer.

 

Would have worked great though because that water was cold.

[The Knome]

Its always about transferring heat from one item to another efficiently.

So from a CPU/GPU to a heat block, to water, to a radiator, to air.
 

For the radiators to work they need air to pass through which is why fans are required. With a big enough radiator, mounted in some kinda funnel solution where convection current can draw air it through the hot air escaping then its a maybe it could work.

But I wouldn't bother hammering the numbers as to how big it would have to be (frankly willing to bet its near a square foot of space per degree Celsius above room temp), to hold the water long enough to disperse that heat with ambient air currents in the room. Just go with as many rads as possible and fans on low speed.

[othertomperson]

My 3960X can idle passively on an H110. I would like to see an i3 with a NH-D15, using just case fans as ventilation. I think that's probably doable.

 

Not exactly high performance, but ok for a passive gaming pc.