Cooling Passive radiator as objet d'art ??

I think that reinforces my point.

Conventional rads NEED airflow, unless they are absolutely HUGE.

For a rad to work passively, the design needs to be different, with lots of outward facing surface area, so that heat isn't just radiating onto another part of the same radiator.

8-ball

 

nah, my old setup was a BIX, 1048 and maze 3 on a 2500 @ 3200 (no gfx/nb) and the fan died on the bix overnight, there was no airflow near it, (i had it resting on top of the psu in my cheiftec dragon, never got round to mounting it properly ) the rad/water was very hot and the cpu temps were about 55 load or something but it didnt crash

 

When you say the rad/water was very hot, like how hot?

If it's over 55, then your probe is giving you the wrong temperature.

I'm not saying it won't work, but it will be nothing like as good as a rad designed from the ground up to be passively cooled.

8-ball

 

dunno how hot exactly, dont have an external temp probe but touching the rad it felt HOT
course it wont work as well as a proper rad designed to run passively, but it did work
the cpu temps were just off the mobo

 

I would suggest that the cpu was running at quite a bit more than 55 deg in that case, and while a system COULD run like this, I guess stability would be an issue, as well as the lifetime of a processor running at these sort of temperatures.

8-ball

 

it did run all night with seti on tho
but the first thing i did when i realised the fan had died was close seti and bodge a fan to point at the rad, helped considerably, even with just an old 80mm in the general direction of it

 

No m8 just a standard Aqua Compuer Airplex Evo. Soz if my post was misleading.

On another note i agree with 8-ball that a rad designed to be cooled by a fan should not be passively cooled. My heatsink slipped slighty off my proccessor and the temps what to 91C pretty quickly Dunno how long it was running like that cause it was unstable for a few days before i got round to looking for the problem.

That was about a year ago and its still working ok!

 

Just a really quick post 'cos I really have to get to bed but I just found a link that I was looking for when we touched on the subject of radiation versus convection a while back...

In the words of the song... we can work it out (...literally - including calculator)

 

Some bad pics of the Zalman passive res/rad supposedly runs warm to the touch but he said it seems to be working well

http://www.legitreviews.com/phpBB2/viewtopic.php?t=76

 

im running my setup with out the rad fan on right now, its 44c at idle and only got to 46 when playing games for hours straight its a p4A 2.4 at 2.71

 

I would just like to say hi to everyone before I start (my first time).

I read the post below about a passive radiator and just wanted to share with everyone my experience of passively cooling my radiator. Despite some natural scepticism it is possible – I have done it.

I have been on a quest for a quiet PC for some time now and fan less seems the way to go (to a certain extent of course – it is hard to eliminate them all). My aim was to minimise the noise in the pc by cooling the main heat generating components such as CPU and GPU using water-cooling. I am experimenting with my old PC. So far, I have done this only with the CPU. I haven’t really bothered with the GPU as it’s a Gforce 3 and doesn’t make much noise anyway.

I achieved passive cooling of the radiator with my old XP1800+ (Palomino). I use a Gemini 3/8" CPU block, an Aquarius 1200 submersible pump, a custom made aluminium tank 125mm x 75mm x 50mm (which the submersible pump sits in), and a double pass twin stacked radiator. I don't know what make the radiator is, it's just some generic make I bought from the US (same place I got the Gemini CPU block from - I'll have to look through my references for the project). The radiator is pretty much like the ones you get in a car as part of the heating system - i.e., the heater matrix (not the main radiator). Piping is a mixture of 12mm and 10mm. The fan I use is a 120mm x 40mm AC (240V AC) fan. This fan is made by Sunon, and can push around 70cfm with a static pressure of 0.08inch/H20 at 36dba at a speed of 2,000rpm (RS order number 498-069). This is a nice and weighty fan as well as it is made from die cast aluminium. I can vary the speed of the fan by using a lamp dimmer circuit (you could buy one of these from any DIY shop).

By gradually turning down the fan speed with the lamp dimmer circuit I constructed I found that I could eventually dispense with it altogether. I turned the fan down a bit at a time and left the system running to test stability each time. Eventually, I left the fan off altogether. The radiator is mounted high in the case above the PSU, so I assume that some convection allows air to naturally pass through and over it. Obviously there is a temperature increase without the fan, but this is acceptable to me. With the fan the temperature stabilises at 25ºC - 32ºC depending on CPU load and ambient air temperature. I believe that the lowest achievable temperature has to be ambient air temperature, since it is this that is used to cool the radiator, and the radiator cools the water, which in turn cools the block and the CPU (pretty obvious – sorry). Without the fan, the temperature can be as much as 10 degrees higher, but never more than 40ºC. I accept that temperature measurements are relative and I am only including these as a reference to the ‘with’ and ‘without’ fan condition. The temperature probe is the one on the motherboard below the CPU. I bent it up and applied thermal grease. When I looked under the CPU the other day I noticed a spot of thermal grease on the bottom of the CPU confirming contact.

I have run the system fan less with 3Dmark 2001SE running twice in a row, I then ran the demo and left the PC running idle for two hours. I then returned and did some CAD and played some brief games. The PC never complained, and temperatures never rose above 40ºC. I did this two days running and no problem. I no longer run the fan in the system. I've never had a problem. The only drawback is that your own paranoia can lead you to constantly check temperatures in case of the unforeseen event; it hasn’t happened yet though. The noise when running the fan at a very low setting is still whisper quiet anyway, it is not distinguishable above ambient noises (really!). The real advantage of the AC fan and dimmer circuit is that you can adjust the fan until it is going ridiculously slow. A drawback of course is that you have to deal with mains voltages (which you do with many pumps anyway).

The only audible noise in the system is the low hum of the submersible pump. I aim to fix this by means of sound damping. I am going to put Neoprene on the mounting points of the reservoir, and I will put an acoustically resistive material inside to act as a jacket around the pump. Anyway, the pump noise really isn’t intrusive.

Obviously, if you add a GPU and Northbridge cooler into the system, you'll probably add twice the amount of heat into the cooling system that my processor currently does. According to AMD specs, the 1800+ running at the voltages I set (standard) should generate around 85W of heat as a rough ballpark figure. The extra cooling elements are something I haven't tried yet, but I will do so in the future. I haven't tried it on any new hardware yet, but when I next upgrade I will. The newer CPUs generate around the 90W figure, or so I've been led to believe, so this should serve as a good guide when I do upgrade.

To sum up, running the radiator passively depends in my opinion on having the right type of radiator (as well as other components), and your expectations of the system. Do you want quiet and stable, or do you want maximum overclocking and stable? I've hardly delved into the world of overclocking so I know how I would answer that.

What do you all think?

 

can i get the cliff notes on that post please.

 

last post was by me, not enigma (enigma is my brother and he logged in on my computer and i didnt know it)

 

Hi All,

Off topic abit.....

Has anyone purchased anything through Kool 'n quiet?

How was the service etc?

They offer some quality bits, that many other comp e-tailers do not hav available.

Cheers and thnx,

Matt

 

haven't been in here in a while .. but i have to agree with 8-ball and Kookalamans with the fact that normal rads just arn't designed to run passive, it will work but no as good as it could, i've been messing with home made passive rads for ages and trying to get silence while something that can perform well enough so i have the option to overclock still... i mean when i've got my cpu,hardrives,gfx,chipset and psu all watercooled on the same loop and my water temp has never gone above 30c .. i think i've sorted it .. but making it more compact is the problem ..... currenly working on a passive phase-change system into the loop to get the coldest and the quietest system i can