To Push-pull or not? Is turbulence an issue?

Baldbloke

Baldbloke

Baldbloke

Associate
Joined
26 Nov 2010
Posts
1,421
Location
Thorne Yorkshire
I've done a little bit of googling on this but failed to find definitive answers.

Using Akasa venom with 1 * push fan at the moment. Will push/pull provide better cooling?

Or is push-pull fans advantage mostly negated by added turbulence? I'm assuming it would be impossible to synchronise both fans to eliminate turbulence. Would added turbulence create more noise? Should fans be a matched pair?

My Asus p8p67 has only 1 * 4 pin cpu fan header. If I were to try push-pull, how would I connect it to a single 4 pin cpu header? Should I just get a 2nd cpu fan with 3 pins and connect to the 3 pin header next to the existing 4 pin cpu header on the Asus p8p67? Thus using one 3 pin and 1 4 pin fan.

Thanks folks.
 
Noctua fan have vortex control notches to reduce air turbulance but at the same time wont have as high static pressure as is needed to ram over some heatsink/radiator setups. Certain manufacturers of heatsinks/radiators do design them to have less resistance and/or efficiency but this also comes at a cost.

With regards to your question id say that ud be best to match fan of acceptable tone and dB. If noise is a concern you really need to be replacing the heatsink/radiators with overspeced parts so that you can run nice ultra silent fans at their lowest rpm and still get the required cooling at load. Sure this is expensive but if your aim is silence there is a little rule which tends to ring true.

cool, silent, cheap

You can only pick two at any time when choosing a cooler.

cool and silent but not cheap
silent and cheap but not cool
cool and cheap but not silent

you get the idea....
 
setter said:
As the fan supplied with the venom is the akasa viper, you would need a second viper and one of theese cables for a push/pull setup.

http://www.overclockers.co.uk/showproduct.php?prodid=CB-031-AK&groupid=1929&catid=153&subcat=

With this adapter power is provided direct from the psu, both fans will run at the same speed therefore turbulence wont be a factor. A push/pull setup will drop temps, but it will vary from user to user.
Click to expand...

Thanks for that. I see from the labels on the splitter cable only one is marked cpu fan. The other two are marked case fan. I imagine the Case fan label could be used as a cpu pull connector? Also, there are only 3 wires, that I can see, connected to the mobo header plug. Would it matter if it went on to 3 pin or 4 pin mobo header?


AceTK, Yes, quiet would be nice but I wouldn't want to spend too much cash on cooling unless I had a temperature problem. (I don't. Just interested in cheap, effective cooling. A compromise, really). I certainly don't want to go down the water cooling route. My pockets aren't that deep.


Thanks.
 
Yes, one fan is connected to the cpu fan connection, then you add others to the case fan connectors, however though, all fans have to be identical PWM models. The motherboard connector has to go to the cpu fan header on the mobo, as this enables the speed control via the PWM function. Ive used this cable for quite a while now and its a really great piece of kit.
 
Currently running a prolimatech super mega with dual fans, havent tried it with a single. However, on my previous cooler, (TRUE black). I saw a difference of 5c when using dual fans compared to a single.
 
setter said:
Currently running a prolimatech super mega with dual fans, havent tried it with a single. However, on my previous cooler, (TRUE black). I saw a difference of 5c when using dual fans compared to a single.
Click to expand...

Hmm thanks, maybe its something i might have to consider. Can you buy the bracets for the megehelems? I dont seem to have another one for a second fan.
 
Turbulence actually improves heat transfer as the air is more mixed, i.e. most of the air comes into contact with the heat sink. If it was laminar there would be cold air spots in between the fins of the heat sink. The notches noctua put on their fans increase turbulence, there are lots of little eddies producing different frequencies of sound rather than one dominant eddy producing a single louder tone which is why they sound quieter.

That said it's still best to have matching fans so that one isn't putting energy into making the other fan spin faster than it is designed for.
 
You must log in or register to reply here.
Back
Top Bottom