Convection Cooling

[Cutless009]

I remember seeing a guide a long time ago on XS about convection cooling using no pump but rather convection in order to move the water through the lines. I remember it was a very specific way it had to be set up though. I want to do this on my HTPC, but I cant seem to find the guide, does anyone know where it is, or was it one of you maybe?

[zlojack]

I think it was Tony from OCZ who tried it.

The rad was at the top so the warm water would go up and get cooled and circulate back down.

[smee]

I think it was Tony from OCZ who tried it.

The rad was at the top so the warm water would go up and get cooled and circulate back down.

Yep and yep. :up:

Heres the thread:
http://www.xtremesystems.org/forums/showthread.php?t=203055

I am planning on trying this myself soon, I'll post a thread about it when I do. :up:

[Cutless009]

mmmmm, I love this message when I click XS Links:

"You have been banned for the following reason:
Trolling

Date the ban will be lifted: Never"

[Kayin]

Funny shit.

Convection works, but you have to have a pretty specific layout. Tell us how it goes, though.

[smee]

Lol cutless, thats funny.... xD

Well, here you go, from the original thread:

Convection.. within a loop its the movement of water by heat alone. Im still designing a new loop for my HTPC but a quick and dirty test has my mouth watering with the fact that i can have my cake and yes..I can eat it to ;)

No pump, no failure worry and complete silence.

At this time im using my ubber loop in the workshop, I will conduct more tests with the crossflow rad I have in mind and bring more info to the table then but for now here are some results.

Q9650 @ stock speeds and voltage. EIST works but the VID does not drop on the P5Q Deluxe so I will have to play around with the Asus EPU six engine...so anything I quote at Idle is 6x333 and load is 9x333 with 1.2375V vid.
Please note it can take a few mins for the convection to get moving, temps initially rise to around 66C load but then once the water is moving they settle to what you see me quote here. Keep this in mind if you decide you want to play also ;)



Im using a Hydroflow block, with around 75LBS of mounting pressure here, coupled with Freeze compound.

Idle is sitting between 21 and 26C:

http://www.ocztechnologyforum.com/staff/tony/Retail%20HF01/no_pump_idle.png

Convection temps:
Flowing in:

http://www.ocztechnologyforum.com/staff/tony/Retail%20HF01/tn_Image8.jpg

Flowing out:

http://www.ocztechnologyforum.com/staff/tony/Retail%20HF01/tn_Image9.jpg

This was taken after a 4 hr load run and then left to idle for 20 mins, next up load temps:

http://www.ocztechnologyforum.com/staff/tony/Retail%20HF01/no_pump.png

This was around 2HRs into a 5 loop Linpack run using max stress with 16GB of ram...ouch!! ;)

Water temps:
Flowing in:

http://www.ocztechnologyforum.com/staff/tony/Retail%20HF01/tn_Image10.jpg

Flowing out:

http://www.ocztechnologyforum.com/staff/tony/Retail%20HF01/tn_Image11.jpg

Now this is not all that bad...firing the pump on drops the temps by a huge amount...but that's not the plan here...the plan is no pump ever in the loop if I can.

All I need now is test the rad with a cpu mounted in case etc...At this time the CPU is horizontal in the board on a bench (not good in itself for convection)

Overall im quite pleased with this, as long as the rad I choose cools the water in the loop pretty efficiently the project should be good to go soon.

I'm not sure if this is helpful at all regarding radiators, but I did run one experiment. I took my TFC480 and set in on my radiator testing bench without any fans on in the room and let it rip with 100watts applied.

About 3 hours later, temps were still climbing and this is the plot of my sensors. The reservoir I use is about 1/2 gallon, so I think the key is the large reservoir for the additional heat storage, although I never would have thought you could get convection to move the water properly.
http://img377.imageshack.us/img377/5105/tfc480passivetestob6.png
So with the 480 rad, I was probably going to level off with about a 20C delta using 100 watts as a heat load. So I suspect a really small heat load could be doable, that or any amount of air that's pushed through the case for something like the PSU would likely improve performance over true passive a fair amount.

I did however have an unintentional pumpless test run while testing the Apogee Drive, I accidentally disconnected my GPU loop pump (reaching back for the backplate) and really disfigured my tubing. The tubing at the GPU outlet was all deformed (Flattened). I logged and recorded that little adventure too, suprisingly though it did seem to almost level out in water temps so I must have been convecting some sort of flow rate.

here is how I have the system now:
Closed Loop, No reservoir, 3x Xilence fans 12V

Idle room temp 20C@ radiator height

http://www.ocztechnologyforum.com/staff/tony/Retail%20HF01/convection_closedloop.PNG

Just run off the first load test run then let it idle for 15 mins to give a good representation of how it would be in a system and its idling at 23>28C dpenedant on what core you look at ;)

Load was a little higher than with the ubber loop once it settled down...i will run it again a post some further info.

Some OC tests, quite pleased with these as checking the Intelburntest thread im matching what some are seeing with highend air cooling.

10 Loops intelburntest, 1.4V set in bios although actual vcore is well below this.

http://www.ocztechnologyforum.com/staff/tony/Retail%20HF01/3.6GHZ_convection.png

Ambient room temp is 20C, air out of rad(top) 34C, bottom 24C, so rad is removing 10C ish as the water flows down each pass.

not bad at all

Hope that helps ya. :up:

Looking forward to testing this myself. :clap:

[Chicken Patty]

damn this is pretty interesting stuff :) THanks cutless for bringing it up and everybody else for posting it and finding it :)

[Chilly]

I can attest to this working :p.

Back when I used the unreliable version of the MCP-355, I had them fail on me all the time, I never really noticed unless I happened to be gaming for more than 10-20minutes at which point my system would crash due to heat. At idle/websurfing though, I would of had the system running for hours(until I started a game) before I noticed the pump failed.

Not high performance, but for a system that outputs low heat in the first place(HTPC) I suspect it could work. Mind you I wouldn't recommend it as it can probbly be cooled better on air(at same volume/noise level), but it does work.

[Septim]

it would be a good experiment though... will look forward to more results from you guys...

[NAekuh]

u guys also remember how large his reservoir was....

[Chicken Patty]

u guys also remember how large his reservoir was....

nope, how big was it, is it in the pictures? I don't see it :confused:

[Cutless009]

nope, how big was it, is it in the pictures? I don't see it :confused:

11 gallons, but I dont thinks this would be necessary, as long as he ran those tests the water would have all reached the same temperature.

[Chicken Patty]

11 gallons, but I dont thinks this would be necessary, as long as he ran those tests the water would have all reached the same temperature.

damn thats a lot lol. Thanks.

[NAekuh]

oh chicken patty thanks for that update... never followed it past down to that..

no that looks like a small water capacity indeed..