is a blowing-out fan after a push-pulled cooler, wasted?

[william_90]

I've a blowing out fan in my case(haf932) right after another blowing out fan part of a push-pulled cooler

i've set my fans in two options
which one is better, yet i donno about the push-pull problem

the second one with push-pull option and a seemingly wasted fan(donno yet)

thanks

 

[Bobnova]

Test both, see if there is a meaningful core temp difference.


What PSU make/model is that?

 

[DAKz]

rule of thumb has always been outside air in from the front/side exhaust air out the top/back. Rule of thumb I use is for every mm of fan in have a mm of fan out. And I think your push/pull on your cpu cooler is a smart move.

 

[william_90]

ok i'll test it but do you have any idea if the number 5 fan in the second picture is extra or not, i mean the #6 is blowing out same as #5, i really donno if distance and size in a push-pull posing can be effective, #6 is bigger and obviously away from the cooler

@DAKz; i didn't get ur point, u mean there's no problem with the second picture?

 

[DAKz]

back in the old days there was a concept called turbo prop, basicly thats what you got going on there with 5 & 6, I see no issues with it, easy to see if it makes any difference is to run it get a temp reading and then simply unplug the one back fan and then take a temp again. TO be honest as long as we have those heaters (video cards) in the middle of our case I would rather have as much air as possible flowing through my case, right now I have 9 fans moving air through my case but I make them flow from the front and side to the top and top back, I try to make sure they are not fighting each other to move air.

 

[DAKz]

I did this real quick to show you whats going on in my case..... The red arrows show the path of air, through the case from sides and front all flowing to top and top rear, the only exception to that is the fan on the video card, ( blue arrow) really they are a very poor design.

 

[william_90]

you were right DAKz, thank you
i had a rising temp 56 for cpu when i hadn't push-pull option but when i arranged it (just like the second picture) it was stable at 52 (using prime95)
you've got 4 fans on top, 2 in a row, according to what u said it must have boost their suction power, i think the big cooler on cpu will make a affecting obstacle for airflow
have you experienced any leakage for ur water cooling, i heard such things happened for some people and whats ur max temp using prime95

 

[DAKz]

No no leaks at all, to be honest with you I treated the hoses on this unit very gentle when installing it, I got to be honest if it wasn't for the great deal I got on this I would have gone for one of the other 240 AIO systems, but so far this one has performed flawless. The radiator is a little easy to damage the fins on and the hoses are not that big to move a larger amount of liquid, but I have to say I am very impressed with it and I did add two more fans to it to make it push pull as you can see in the pictures I posted before. I am 57 years old, so me adding a liquid cooler is a bigger step then it was going from MS-DOS to Windows, but now just like then it was a good move.
I just finished raising mine up to 4.63ghz and after 30 minutes on prime it got to 57c-58c but it held very steady there and once I stopped prime it cooled off almost instantly. And right now it is running about 31-32c under my normal use, LOL Playing Modern Warfare 3 and running firefox, so I am good at 4.63.

 

[ehume]

Ah, the old Hyper Z600R. I put one of those in my daughter's rig, with a San Ace "Silent" lowspeed. Quiet.

The nice thing about a pull fan on a heatsink is that you can cut out the rear grill and dispense with a case exhaust fan. The air coming from the pull fan will entrain case air and send it out. That is, in fact what I do.

 

[william_90]

Ah, the old Hyper Z600R. I put one of those in my daughter's rig, with a San Ace "Silent" lowspeed. Quiet.

The nice thing about a pull fan on a heatsink is that you can cut out the rear grill and dispense with a case exhaust fan. The air coming from the pull fan will entrain case air and send it out. That is, in fact what I do.

if u mean removing the push fan from push-pull and let the case airflow to push air into heatsink, it wont work, i found out, only close touch push-pull works out in this case, i tried considering that to no avail, cpu cooler just needs the fans to stick to it, it was proved to me by comparing the temp rises
the second picture had best performance
tnx for reply

 

[ehume]

if u mean removing the push fan from push-pull and let the case airflow to push air into heatsink, it wont work, i found out, only close touch push-pull works out in this case, i tried considering that to no avail, cpu cooler just needs the fans to stick to it, it was proved to me by comparing the temp rises
the second picture had best performance
tnx for reply

That is not at all what I meant. You leave your heatsink in a push-pull configuration. In this thread, I show how a push-pull on a heatsink can evacuate a case. There were no case fans, yet air was being sucked in at every fan window, all of it pulled along under the influence of the heatsink's pull fan.

Bottom line: if you want to choose between an exhaust fan and a pull fan, go with the pull fan and get rid of your rear grill. It seems that the only use for an exhaust fan is to overcome the resistance of the rear grill. If you remove that exhaust fan with the "grill" still there (it is really just a perforated area in most cases) you will not feel the effects of your heatsink outside your case. Remove that obstruction and you will fell the effects of your heatsink.

 

[DAKz]

Maybe I am "old school" but to me I put fans all over the place. moving air everywhere. Noise I don't care about, thats what the surround sound has to deal with. But if it helps move the air then it is worth its existence. I added another fan last night to the mobo cpu mounting plate so thats 10 fans on a liquid system,

 

[Conumdrum]

DAKz, agreed, add a fan if there is a hole.

 

[ehume]

Yes . . . and not quite. I can definitely see putting a filtered fan in every place you want air to go into a case. I have three 140mm and three 120mm fans in mine. But they are all intake, and five of the six run quietly at 800 rpm. The sixth is a TY-140 140mm PWM fan connected to the same PWM signal as the push-pull PWM San Aces on my heatsink. The backplane has no obstructions, and the place where the rear grill used to be is an empty space.

I did the p-p heatsink-only setup for experimentation only.

But I do recommend getting rid of all obstructions and letting air go out on its own.

 

[DAKz]

As I have mentioned elsewhere...to me a simple rule of thumb is for every mm intake have a mm of exhaust. Moving air in a case is the best way to keep things cool that are low on the list for cooling. And I agree about obstructions, thats why cable management is so important and the newer cases with mesh all over them are great. Fans are cheap use very little power so if in doubt be a fan of the fan.

 

[ehume]

Fans make noise. When you don't need a fan, don't make the noise. Air will find its own way out, if you don't bottle it up..

 

[Conumdrum]

Agreed, if temps are fine and noise is an issue, why add a fan?

I go both ways on this, if you want a fan add one. If you don't need it, then don't.

It's a personal decision.

 

[DAKz]

Agreed, if temps are fine and noise is an issue, why add a fan?

I go both ways on this, if you want a fan add one. If you don't need it, then don't.

It's a personal decision.

I agree its a personal choice. But I am old, so hard of hearing and all that so fans make very little noise, also with a fan controller you don't have to run them full speed all the time if the situation don't require it.