poll Rear Fan - What Style Do You Prefer?

[Awakening]

Just a simple poll to see how many people like the look of a round 140 mm fan as a rear exhaust over a traditional 120 or 140  

[Luc401]

My cases only hold 120mm, but id gladly put a 140 if I could.

[kosamchetoo]

Put the biggest one your case supports.

[WoodenMarker]

3 hours ago, kosamchetoo said:

Put the biggest one your case supports.

^

I use rounded 140mm's if possible when the rear has 120mm mounting holes.

[LogicalDrm]

140mm would be my choice. But since case doesn't support such on rear, I have 2x140mm top exhaust instead.

[Awakening]

20 hours ago, kosamchetoo said:

Put the biggest one your case supports.

Got it. I'll take my side panel off and tape one of these to the side of my case for exhaust.

 

 

Thanks!

 

8 minutes ago, LoGiCalDrm said:

140mm would be my choice. But since case doesn't support such on rear, I have 2x140mm top exhaust instead.

 

 

I hope you've got at least three intakes then or two at higher CFM than the exhaust. If not, it's gonna get dusty.

[LogicalDrm]

2 minutes ago, Awakening said:

I hope you've got at least three intakes then or two at higher CFM than the exhaust. If not, it's gonna get dusty.

Got 200mm fan running at full speed. Overall its negative pressure, but only vents get dusty. Not that bad inside the case. I'm changing case soon so then I will have 2in, 1 out.

[AngryFishLady]

I have a 120mm as intake and 140mm on top as exhaust, am I doing this wrong ? '_'

[Awakening]

16 minutes ago, AngryFishLady said:

I have a 120mm as intake and 140mm on top as exhaust, am I doing this wrong ? '_'

Yes.

 

 

[AngryFishLady]

Just now, Awakening said:

Yes.

 

Can't watch the vid right now, I'll check later. Basically I put it as intake because I have 2x120mm in front but wanted to make sure pressure was enough inside the case. The front are reacting to the CPU temp so they don't blow much most of the time, and my top 140 is on 75% power all the time, so I wanted a baseline for intake.

[Bananasplit_00]

my case takes a 80mm rear fan lol, i dont even have one in there either  would gladly slap a 140mm fan in there if i had one and it fit but there is litteraly no benefit in doing that for me anyway lol

[Awakening]

You basically just need to aim for a greater CFM coming into your case than what's going out of it. This will create an environment that is dust resistant while the doing the opposite will attract dust. If you don't have any fan filters for your intakes though it probably doesn't matter a whole lot.

 

If you have two 120s in the front and a 140 exhausting then it should be pretty easy to get positive pressure with that. Just make sure your two intakes are spinning at a similar RPM or higher than the exhaust. If you want to get really precise, you could go here, find your fan models, and see what CFM each fan has at what RPM and then use that info to calculate what your fans need to run at for positive pressure. For example, if your 140 hits 50 CFM at 1000 RPM and a single 120 hits 35 at 1000 RPM, set both of your 120s to ~730 RPM or higher. Both together would produce a little over 50 CFM. If your intakes have anything blocking them (e.g. HDD racks, fan filters) that your exhaust doesn't, you'd want to set it at ~830 RPM, at least 100 RPM higher.

 

That's just getting precise with it though. It really isn't that difficult to accomplish.

[AngryFishLady]

Thansk a lot for the answer. I grasp the concept of basically, the more difference between intake and exhaust the more pressure. However, as said above, the two 120mm intake have variable RPM depending on the CPU temp, so they may not intake that much all the time, hence the additional 120 that have a constant RPM.