Airflow Suggestions

[patriotaki]

Hello all i got the 400c and i want to fix my airflow because my CPU temps are 30-33C, in my old case Fractal XL Black Pearl it was 25-29C.
First i want to change the front stupid molex fan, should i get Static pressure or Air flow fan? Which fans do you recommend?
I also have the COoler master 412s CPU Cooler in push pull conifg, using the preinstalled fan as pull and the corsair sp120 as push

Top and rear fans are exhaust

 

Later on im going to change the Cooler Master 212EVO Fan also, cause its making alot of nooise

 

My setup:

Cooler master 212evo fan = 1600rpm,66.3cfm
the molex fan ..idk its an old fan that was laying around lol. Its from superflower
corsair AF140 = 1150rpm,68cfm

AF140L = 1000 RPM, 67.43 CFM,
AF120L = 1300 RPM, 57.13 CFM

 

PS: Dont judge my fail attempt for a quick "mockup"

 

[Mira Yurizaki]

I'm a subscriber to the positive case pressure setup... but conventional wisdom would put your configuration in negative case pressure.

 

So I'm going to go against conventional wisdom: top and front fans intake with the rear fan as exhaust. People will tell you top fans help remove hot air due to natural convection... but natural convection produces so little airflow that it doesn't matter. Forcing colder air in is going to win out over the hot air going up on its own. And since colder air is denser, it may even push out the hot air through the cracks of the case.

 

The only problem of course is you're going to need filters.

[Bleedingyamato]

What if the top front fan was removed?  It would technically still be negative pressure since there would be 2 120mm in but a 120mm and 140mm out but the lean towards negative pressure would be rather slight.  

 

Another option would be the same but in addition to removing the forward top fan (the AF 140) the rear top fan could also be removed and switched to an AF120 to attempt to balance the airflow between intake and exhaust.  

 

I'm actually trying to figure out an optimal fan setup for my NZXT Phantom 240 case and one of these two fan configurations is what I'm considering using.  I thought perhaps the ideas could help here.  

 

I've looked at a YouTube video from Linus that said that even airflow is best but leaning towards positive pressure slightly.

 

I hope all that was in some way helpful.  I don't know much about airflow and fan setups I'm afraid but I thought I might have something useful to contribute.

[patriotaki]

Thank you all for your posts!

I get few degrees higher temps on CPU and I thought that its because the fan that's facing to the CPU cooler is bad and old thats why I wanted to replace it.

 

Oh and btw..I'm a dust maniac  

 

Having equal amount of fans as intake and exhaust is a good solution?

 

What if I make the af140 that I have as intake and the other two fans as exhaust?

[Bleedingyamato]

19 minutes ago, patriotaki said:

Thank you all for your posts!

I get few degrees higher temps on CPU and I thought that its because the fan that's facing to the CPU cooler is bad and old thats why I wanted to replace it.

 

Oh and btw..I'm a dust maniac  

 

Having equal amount of fans as intake and exhaust is a good solution?

 

What if I make the af140 that I have as intake and the other two fans as exhaust?

Even in and out is at least what I'd suggest.  Though some sort of positive pressure is best from what I've heard.  I agree with Yurizaki in that I believe you should use positive pressure.  I may be misunderstanding what Yurizaki is suggesting but I think you should try the front 2 fans as intake along with the af140 in the front top spot.  Then use the rear top fan that came with the case and the rear 120mm fan both as exhaust.  That'll should give you positive pressure I think since you'd have 2 120mm and 1 140mm intake and 1 each of 120mm and 140mm exhaust.  But I'm not sure if having one top fan as intake and the other as exhaust will work or if that would cause some odd airflow in your case.

 

Otherwise Yurizaki could be meaning for you to use both front and both top fans as intake with just the rear 120mm as exhaust.  Or maybe that setup but using the rear 120mm as intake with the rear top 140mm as exhaust instead.

 

"What if I make the af140 that I have as intake and the other two fans as exhaust?"

I'm not sure which other two fans you mean for exhaust sorry.  But I think if you try one of the fan configurations that I just mentioned in trying to figure out precisely what Yurizaki meant.

 

Hopefully Yurizaki will check back and can other more help and details to assist you further.

 

Also, as an alternative to a 212 EVO maybe try looking at getting a Cryorig H7 since I think it's supposed to be pretty good.  Idk about noise but you could check on that. Though replacing the fans you have on your 212 EVO may reduce the noise too.  Either way I thought I'd mention it just in case.

[Mira Yurizaki]

Sorry, I was out all day (in Japan time).

 

So this is what I had in mind. The green arrows are where airflow should be going. The blue one in the top left is optional. I don't think it'll help or hinder since it's directly perpendicular to the CPU's airflow.

[patriotaki]

2 minutes ago, M.Yurizaki said:

Sorry, I was out all day (in Japan time).

 

So this is what I had in mind. The green arrows are where airflow should be going. The blue one in the top left is optional. I don't think it'll help or hinder since it's directly perpendicular to the CPU's airflow.

thank you thats what im going to do i already turned upside down the af140..but i need to replace the stupid old molex fan..which fan do you reccomend?

i can buy only from this store http://www.skroutz.gr/

[Mira Yurizaki]

I haven't really bought fans... I just know better CFM and lower dB is best.

 

If you're getting motherboard header fans, make sure you have enough headers. If not, you'll have to buy a splitter.

[patriotaki]

1 minute ago, M.Yurizaki said:

I haven't really bought fans... I just know better CFM and lower dB is best.

 

If you're getting motherboard header fans, make sure you have enough headers. If not, you'll have to buy a splitter.

already got a splitter

how much cfm should i be looking aT?

[Mira Yurizaki]

I'm not really sure about hard numbers. As I said I haven't really bought fans lately. I've been fine with the ones I get in the case. I'd say pick a noise target and get the highest CFM fan you can get within that target.

[Bleedingyamato]

Depending on who I've asked I've heard the non-led corsair fans (quiet edition if lower noise is wanted) are good.  Noctua too I think.  I've seen good reviews for a brand called Cougar as well.  Maybe Cooler Master but I'm not sure about that brand.

 

In general again Yurizaki is correct better cfm with lowest db is best.  With that many fans in your case I doubt it'll matter much which fan you get so my suggestion is unplug all but one of your case fans and listen to the sound coming from it.  Then depending on how loud that seems to you select a new 120mm fan with either the same or a lower db rating.  Basically this will help you do what Yurizaki said and pick a target noise level that you don't want to exceed.

 

It's not something you need to worry too much about I don't think.  So just find a fan you're happy with and buy it.  ?