Anyone built a passive water cooler?

Mark R

Diamond Member
Oct 9, 1999
8,513
16
81
Just wondering if it would be possible to build a passive (gravity-pumped) water cooler.

Has anyone managed to do this for CPU cooling?

What size tubes did you use (I'd guess you'd need at least 1 1/2" diameter), and what type of radiator did you use?
 

Ayah

Platinum Member
Jan 1, 2006
2,512
1
81
Somehow I doubt this would be possibly. You'd need a mechanical pump at least. The MCP350s are pretty quiet ones.
Something like an Apogee, 1/2" tubing, The biggest freaking radiator you can find (Car radiator would be good).
 

Gautama2

Golden Member
Jun 13, 2006
1,461
0
0
If your looking for passive water cooling you could fill your case with vegetable oil like the folks at toms hardware did a while back.
 

Mark R

Diamond Member
Oct 9, 1999
8,513
16
81
Originally posted by: 0roo0roo
gravity pump?

Hot water is less dense than cold. Gravity pulls the cold water down below the hot water.

Arrange a loop so that heat source is at the bottom, and heat sink is above it, and gravity will generate a circulating current drawing heat from the source to the sink.

This principle is well established - it's used in domestic hot water systems. The furnace is in the basement or ground floor - but hot water storage tank is on an upper floor. Gravity moves the hot water from the furnace to the storage tank, and the cold water is drawn back down to the furnace.



 

Gautama2

Golden Member
Jun 13, 2006
1,461
0
0
Originally posted by: Mark R
Originally posted by: 0roo0roo
gravity pump?

Hot water is less dense than cold. Gravity pulls the cold water down below the hot water.

Arrange a loop so that heat source is at the bottom, and heat sink is above it, and gravity will generate a circulating current drawing heat from the source to the sink.

This principle is well established - it's used in domestic hot water systems. The furnace is in the basement or ground floor - but hot water storage tank is on an upper floor. Gravity moves the hot water from the furnace to the storage tank, and the cold water is drawn back down to the furnace.

Its not gravity, gravity pulls mass. The speed of the particles doesn't affect the mass. Convection causes heat to rise.
 

Navid

Diamond Member
Jul 26, 2004
5,053
0
0
Originally posted by: Gautama2
Convection causes heat to rise.

Heat does not rise. Heat is energy not matter.

A hot fluid rises because it is less dense than the cold version of the same fluid. It is gravity that causes the colder, hence heavier, fluid sink to replace the warmer, hence lighter, fluid.
 

KBTuning

Senior member
Mar 22, 2005
357
0
0
i dont think you could make the fluid at the top cold enough for this to work... it would just heat up everything and then overheat... that is unless you had some sort of ubercooler on the other end...
 

CurseTheSky

Diamond Member
Oct 21, 2006
5,401
2
0
It could be done, but it wouldn't cool well unless you let the liquid cool OUTSIDE of your system. The Zalman Reserators are good examples of this.

Keep in mind, though, that you're be relying on your processor (or other components) alone to move the liquid. It'll be moving much slower than in a pumped system, and most likely be cooling less efficiently.
 

beemercer

Senior member
Feb 10, 2006
817
0
0
I remember seeing a system that worked by hot water rising to the top, and the cool water sinking (fully passive) but the cooling performance was terrible.

Also if you live by a stream you could route the water into your house, into the waterblock, and then back out to the stream. This would rely on the flow of the stream to pump the water through the system.
 

CTho9305

Elite Member
Jul 26, 2000
9,214
1
81
Wouldn't something that expands/contracts more be better than water? They use alcohol and mercury in thermometers, so maybe one of them.
 

TheRyuu

Diamond Member
Dec 3, 2005
5,479
14
81
Originally posted by: CTho9305
Wouldn't something that expands/contracts more be better than water? They use alcohol and mercury in thermometers, so maybe one of them.

I can just see the headlines.

"Man killed from mercury vapor trying to cool his PC"
..."dumb ass"...

:D

I really don't think Passive Cooling is worth it.
You can still build a very quiet PC with something like some Yate Loon fans on the Rad and the same in the case (so it'll be very quiet).
 

MoonglumWoW

Member
Dec 18, 2006
33
0
0
Originally posted by: Mark R
Just wondering if it would be possible to build a passive (gravity-pumped) water cooler.

I don't think it would be possible to use a GRAVITY pump for cpu cooling. A passive water cooler for CPUs usually refers to not needing a fan and/or radiator for cooling, but an ELECTRIC pump is always required to move the coolant. There are lots of passive water cooling articles to search for on overclockers.com, and you can pay particular attention to the issue of "flow rate" through the system. In testing, even the minimal flow rates would not be possible with a convection system. Some type of pump, mechanical or electrical, would be needed.
 

andy04

Senior member
Dec 14, 2006
999
0
71
I agree, convection can be used to circulate the fluid but the problem is that the temp difference between the hottest and coolest fluid should be high for the flow to work effectively and you cannot let the temp on your CPU rise to that level therefore it cannot work.
One possibility is to use some liquid much thinner that water... like spirit then again that will be dangerous...

Bow down before the Nature !!
 

Fullmetal Chocobo

Moderator<br>Distributed Computing
Moderator
May 13, 2003
13,704
7
81
"IBM has also put a liquid cooling system to work in some of its servers. But its system is passive, meaning the liquid isn't cycled round by a pump; instead, cool liquids sink, then rise when heated up, to be replaced by falling cool liquids."

Source. I was doing some research, and I thought you might be interested in this....
 

aigomorla

CPU, Cases&Cooling Mod PC Gaming Mod Elite Member
Super Moderator
Sep 28, 2005
21,019
3,490
126
there have been many attempts at making a passive watercooling system. Problem is when you try to overclock, the flow of water isnt fast enough to keep up with the raising heat from the cpu.


But its not at all impossible, XBOX 360's have been cooled passively, but it still required some sort of pump and a passive heat exchanger.

Watercooling without any flow and using convection to force water up and down however would be almost impossible. You would need to L neck the water from the cpu straight up and have absolutely no obstructions, it would be more messy then its worth.

Originally posted by: andy04
I agree, convection can be used to circulate the fluid but the problem is that the temp difference between the hottest and coolest fluid should be high for the flow to work effectively and you cannot let the temp on your CPU rise to that level therefore it cannot work.
One possibility is to use some liquid much thinner that water... like spirit then again that will be dangerous...

Bow down before the Nature !!

This guy is absolutely correct. You would need to use a spirit, but each time u pressed that on button, u risk blowing your machine up along with half your room. :p
 

Smartazz

Diamond Member
Dec 29, 2005
6,128
0
76
Originally posted by: Gautama2
If your looking for passive water cooling you could fill your case with vegetable oil like the folks at toms hardware did a while back.

Or you can get a Zalman Reserator.
 

aigomorla

CPU, Cases&Cooling Mod PC Gaming Mod Elite Member
Super Moderator
Sep 28, 2005
21,019
3,490
126
Originally posted by: Smartazz
Originally posted by: Gautama2
If your looking for passive water cooling you could fill your case with vegetable oil like the folks at toms hardware did a while back.

Or you can get a Zalman Reserator.

and risk masive pump failers that a lot of owners have? You can google it and find out yourself on my statement. I dont know about the new one tho, but id stay alway from the old one.
 

andy04

Senior member
Dec 14, 2006
999
0
71
ok... in case you missed it, we are talking passive here. This bong has 2 pumps and a Fan - definitely NOT PASSIVE.