Building your own passive system

[debay777]

I would like to start this thread to see who is interested, who has tried it, who has succeded, and who has failed. I am currently tossing around the idea of bulding my own fanless( or at least a nearly fanless/noiseless) cooling system for my machine. I will be using an Antec Aria case. these are nice cases, but tend to be very hot. im moving up to the AMD 64, and the chaintech geforce fx, so internal temps are going to be high. I have a small airport (by the sound of it) operating in my room now and i want quiet.....i dont want to hear anything. i really like the resorator 1, but the price is, well its high. in my somewhat uneducated opinion, there has to be a better way to make a cooing tower with more surface area, better flow, better heat dispersion, and all at a cheaper price. The guidelines for my design will be similar to the resorator i.e.- submerged pump- large res.- simple, yet large surface area for heat dispertion. i would like to improve the resorator idea by including more flow and a better/more efficient way to get the heat transfered to the air. im not opposed to using a low speed silent fan(s), bt i would like to avoid it. well, fire away. im sure some of you are going to crucify me, but im sure someone is interested.

[sevisehda]

When I looked into passive systems I came up with the plan to build a large radaitor from 3/4in copper tubing. At first my idea was to place it on a wall, then I realized if I could get it between the ceiling and the ceiling fan I could move air very slowly over it. Not sure if that would fit your need or not.

[JWFokker]

You could try setting up a couple oil coolers, which is more or less what the Reserator is based off of. You'll probably want an Eheim pump too, if you're going for silence, probably a 1250 or 1060 with the amount of tubing you're going to have, and I assume you'll watercool the GPU too. The only thing is though, I think the oil coolers might be aluminum if I remember correctly. Maybe try a crapload of soft copper tubing instead, like the Xice passive cooler?

The Xice:




Of course, they use 8mm tubing and there's about 10 meters of it but maybe to improve flow you should use 1/2" stuff and put a low rpm 120mm fan at the top. Get a SilenX and you'll never hear it. The few people who've had passive watercooling kits have said they greatly benefit even from a very low rpm fan blowing on it.

Your temps won't be great, probably only about as good as stock heatsink temps, but it'll be damn near silent.

[debay777]

give me an idea of what type of radiator you plan to use. i was actualy looking at some aluminum pipe and some flat stock. i came across some aluminum soldering supplies at a trade show that uses a standard propane torch. the guy was patching nail holes in soda cans, and welding beer cans together with it. the stuff was neat!! one of the ideas i was looking at was a cyclinder made up of smaller diamater aluminum pipe with the same type of verticle cooling fins as the resorator. all of the pipes would be connected( the logistics of flow, method of connection, and everything else is till up in the air) with a silent fan running at the bottom blowing straight up. we have tons of boat shops out here who have scraps of aluminum laying around that just might fit the bill. and a friend of mine anodizes paintball markers, so i just need to buckle down and try it. any suggestions would be great.

[debay777]

with no more than what i plan to do with my computer, i dont think my temp will be a problem. i only occasionaly get into playing games on my machine anymore. i mess with battle field 1942 and crimson skies some, and thats about it. just out of curiosity, the zalman video card kit comes with two water blocks( im not exclusively lloking at these, it just got me thinking) to fit multiple styles of GPU's. is there any reason i cant stick the spare (or just buy another smaller block) on the north bridge? thats just one more heat source being washed away.

[JWFokker]

I'd go with a Zalman passive NB and a Silverprop Fusion GPU block, as it's all copper so no worries about corrosion.

I'd have gotten one from Criticool but they were all out, so I got the MCW50 instead. If only I weren't so impatient....or maybe if Swiftech made an all copper GPU block....

[debay777]

the silverprop looks stout enough, but it covers the Ram heat sinks on that particular video card. ill have to check it out.

[debay777]

itll work fine on the chaintech geforce sfx im getting.

[Kobuchi]

Try to place your radiator under a window. There will usually be a temperature differential between the glass and ambient, one way or the other. This means you can assume vertical convection of air beneath it, and that will help your radiator.

[bobkoure]

You might also make use of a chimney (no kidding).
Putting something hollow (open at the bottom and the top) may give you some additional air flow without having to use a fan. To see what I'm talking about, make a tube with a piece of paper and hold that above a heat source, like a light bulb.
I'm surprised they didn't do something like this for the reserator - maybe the additional size makes it impractical...

[debay777]

thats actualy the basis of my idea!! the plan that im am tossing around is a res. made of a double walled cylinder with a small silent fan at the bottom blowing straight up the center. there would be fins or ridges similar to the resorator on the outside and if possible on the iside of the cylinder too. i would like to use large diameter pre-made metal (preferably aluminum) tubing for the res, but i will have to see. some of the metal pipeing i have seen is ridged , which means more surface area!! inside the res i am thinking about running a small coil of copper tubing that will (1)spread the heat evenly around the res. and (2) dump the hot water on the opposite side of the cylinder than the pump so that im not recirculating the same hot water i just put back in. i know the addition of a fan is not passive cooling, but it might need to be there in case i get busy!!

i now have a rough draft (really rough) that shows the basics. not shown are the water fill and several small details.

[Kobuchi]

Before you go trailblazing, debay777, do consider that designers of electric room heaters have pretty well the same goals as you. You have pipes to cool, they have elements, both need to transfer that heat to room air. They've had a hundred years and plenty of government money to work out the most efficient systems.

[debay777]

yes they do, but like all things there is a price to pay. electric room heaters are good at what they do, but if they were usining the fans and blowers that produced maximum heat exchange then you couldnt so much as talk in the same room with it. my personal goal is to just finagel around with some basic ideas to see if they have merrit. my goal isnt so much maximum effiency as much as it is for maximum quiet. im going to have to trade off efficiency for that, i know. thats the cost. if i can find a happy medium where both the machine and i are happy at a greatly reduced cost to a store bought system, then my goal is accomplished. i hope to start in the next week or so, and i plan on documenting what i do along the way. if anybody has blazed this trail before, their assistance would be greatly appreciated.

[bobkoure]

Originally Posted by Kobuchi

... consider that designers of electric room heaters have pretty well the same goals

I suspect it's quite different.
The heater designers (and hydronics heat element designers for that matter) are dealing with moving heat out of something that's 30C (or more - electrics are probably lots more) warmer than ambient.
IMHO, a PC watercooling system (passive or not) that runs coolant 30C warmer than ambient is a failure.

[Kobuchi]

I didn't mean for you to buy an electric space heater, just consider how they're designed, located, and why. For passive, a wide horizontal on a wall and near the floor proves best. This best exploits typical convection currents within most rooms. If you'll use a fan, then there too are many neat designs, and rest assured these models are library quiet.

No shame in copying proven design.

[debay777]

i found a forum where a man actualy ran his water system out into his garage into a large copper pipe manifold. the manifold ran along the ground much like a space heater would along a wall. he wasnt a gamer, but for his needs, it was just right. i have to say that your idea is good, a low system next to the floor would be ideal, and is something i will look at, after i push this little idea around some more. thanx

[*klonk*]

I use a normal livingroom radiator that's laying on a kold celler floor - delta is about 10c - but im not taking it to LANs anytime soon

[debay777]

you mean like a space heater/radiator? wow ,that sounds big. give me some dimensions

[fhorst]

If you want to go passive.. you can calculate what the dimensions need to be with your load.
2x double heatercore (so togeter 25x25x5 cm) should do the trick if you are below a 30 degree room temp.
this is for a "normal 130W" load, and a CPU core temp about 45 degrees.

[Kobuchi]

Often one can make something big innocuous by blending it into the room. A wall-to-wall span, with a valance matching the wallcovering, for example, could probably grace your dining room without comment. It just wouldn't register. But even a small contraption raw and freestanding will hit you like a dalek every time.

[debay777]

lol, a Dalek, thats been a day ago, i used to love that show!!! i just might have to have a dalek cooling tower now. this idea of the passive system hidden in the house structure is neat. ill think about that

[*klonk*]

about 33cm x 55cm - holds about 3 liters i estimate

[debay777]

due to my lack of funds, lack of ability to weld thin aluminum, im having to can thte idea of my little resorator wanna be. im sure that it could be made and made to function right, but until i can get the equipement, im just gonna go the easy rout. im goin to get a thin walled 5 gallon metal bucket and paint the inside to prevent the metal to metal corrosion and run a series of copper tubes around the inside right up against the walls. the pump will be submerged. i figure that ought to keep everything cool, if it doesnt ill just throw in some ice. i know that will work. the water will always be at lower than ambient room temp. it would take a ot of heat to turn 5 gal of water to over room temp. like i said, if i know im gonna play hard, ill just throw in some ice. simple, easy. quiet. i can keep the bucket under my desk, no one will even see it.

[JWFokker]

Be careful of condensation if you go sub ambient. Your tubing and waterblocks may sweat.

[debay777]

hadnt thought of that, how do i prevent condensation ??