push/pull on rad

[Masterchief]

is there any benefit to having a push pull config on a rad ie 4 fans on a 120.2 2 pushing 2 pulling, currently have 2 fans pulling air through the rad but just wondering if it would help having 2 pushing through it as well :shrug:

[alo]

It has been proved that having fans in push+pull configuration will give you about 50% better air flow through your rad.

Now you decide whether you need this or not. :)

[Waterlogged]

It has been proved that having fans in push+pull configuration will give you about 50% better air flow through your rad.

Now you decide whether you need this or not. :)

Maybe if your using 5v YL d12sl-12's on a BI GTS rad, otherwise this is totally wrong. Check out Marci's testing on the PA160 about half way down the page.

http://www.xtremesystems.org/forums/showpost.php?p=1092111&postcount=1

[Masterchief]

Maybe if your using 5v YL d12sl-12's on a BI GTS rad, otherwise this is totally wrong. Check out Marci's testing on the PA160 about half way down the page.

http://www.xtremesystems.org/forums/showpost.php?p=1092111&postcount=1

so looking at that link they i would be better of getting a shroud for my pa120.2 and sticking with the 2 fans :shrug: sorry if this is sounding noobish

[Nosfer@tu]

Just have your fans Pull air throw the rad. That will give you better performance then blowing trow:)

[phelan1777]

I have a PA120.3 with shroud and fans on pull. Other then the mad amount of dust I clean off once a weak I am happy with the performance.

[Serpentarius]

50% more noise, 20% more performance ~ read somewhere .. can't reference

[Conumdrum]

My turn!

You will get a bit more performance with a pull config. And a bit more with a shroud pull. And a bit more with a push/pull shroud. But it won't make up for a too small rad.

Looking at your pics, putting the rad (with case fan holes hole cut darnit!!!!! for best air flow) right on the case and the two fans in pull will prolly be enough. As long as you don't toss the GPU and NB in.......

[LogAn'sRun]

Now see, here we go again.

Reading Marci's post, he states 2x fans in Push-Pull is of no major benefit over 1x fan in push.

So can someone tell me what it is? I thought it had been tested that without shroud, fans in push (ie. fans above rad in top mount pushing air through the rad) was better than pull?

[Pedalmonkey]

pull is better, push pull not too much better than pull.

[Waterlogged]

Again...anyone reporting increased performance with push/pull, is doing so with low CFM fans and a restrictive rad/heater core. You will not see any appreciable gains on a PA series rad.

For a PA series rad I have 3 mounting recommendations.

1. Pull

2. Pull w/shroud (this will allow you to run slightly stronger/noisier fans as the shroud has a slight "silencer" effect but this comes with the "thickness" caveat).

3. Push w/shroud (this setup will further offset the fans from the rad allowing the "dead spot" to be pretty much neutralized and allow all areas of the rad to receive fresh air, again "thickness" caveat).

[Masterchief]

2. Pull w/shroud (this will allow you to run slightly stronger/noisier fans as the shroud has a slight "silencer" effect but this comes with the "thickness" caveat).


currently have it in a pull config and got a shroud on order but am just wondering about this thickness your on about???? how does it fit, any pics :shrug:

[Waterlogged]

currently have it in a pull config and got a shroud on order but am just wondering about this thickness your on about???? how does it fit, any pics :shrug:

Well, the pic isn't mine but it does show kind of how it mounts with the three screw holes on the side.

http://i240.photobucket.com/albums/ff121/Ripp-221/IMG_0728.jpg

Original post is here.
http://www.xtremesystems.org/forums/showpost.php?p=2532484&postcount=107

[CrazyJoe]

Found here - Some New Test Equipment (http://www.xtremesystems.org/forums/showthread.php?t=150261&highlight=test+equipment)

By Cathar -

I found the noise level differences, and the fan speed differences to be quite intriguing. If the fan is spinning faster, it's pushing more air-flow in the blow-mode.

However, using the anemometer on the other side found that with the shroud, in blow mode, the air coming out the edges of the radiator had about an 80% higher velocity that the air coming out the dead-center. In suck mode, the overall air-velocity appeared lower (will need to measure properly later on full-testbed), but it was more even, with only about a 25% variation between the edges (higher) and the dead-center (lower).

So yeah - this throws a cloud over the general suck/blow debate. The fan appears to like to blow much better than to suck, but the air-flow is less even, even though it's of a higher velocity. The fan is also quieter in blow-mode.

It would appear (without further testing) that putting a fan into blow-mode on a radiator with a really deep shroud (60cm) to straighten out the air-flow would be the best way to go, but that's not terribly practical.

It will be interesing to run some tests with varying shroud depths to determine what gives us the best approximation at an even air-flow through a radiator in blow-mode. The current shroud I'm using is a custom job that I made up, that's 6cm deep. I suspect that differing fan shroud depths may favor suck/blow in different amounts.

I then want to apply the guidelines gathered as a result of these tests to measuring actual radiator performance, NOT JUST airflow vs noise, but actual cooling performance with a 200W heat-load. Given that different fans will have different air-spread characteristics, and so create different air-flow speeds through different regions of the radiator, I don't think it's going to be as cut and dried as a "dry run" test of noise vs air-flow. It's going to be noise when mounted vs air-flow vs air-flow characteristics.


Essentially, Pushing fans offer higher flow but Pulling fans yield a better distrobution over the rad. Push-Pull would give you the best of both worlds. :up:

[septim]

pull will probably give a more "even" airflow throughout the rad, especially with the gasket and even more so with added shroud.

simple testing with an open ended box and fan on pull, will even pull the air from corners
VS fan on push, air in the corners gets left...