Question Meshify C Air Flow Questions

[WolfLikeMe]

So I'm rebuilding the household gaming PC and for the first time really considering my air flow setup. I'm guilty in the past of just running whatever stock fans my case came with, maybe a budget CPU air cooler, call it a day. Definitely had some serious negative pressure in my last setup, dust everywhere including exterior cracks.

So I've done a little research on air flow, goal is slightly positive pressure, as many guides and videos recommend.

Building in a Meshify C case, I purchased 2 extra 140mm Fractal Venturi fans (118cfm) for intakes on the front bottom. Moved the 2 stock 120mm Fractal GP-12 fans (52cfm) to the back top corner for exhaust (one "roof" and one back wall). Also I have a Phanteks CPU cooler PH-TC14PE in the mix, it's 2 fans (23-69cfm each) are pointed to the back wall of the case. Let's say ballpark ~100cfm in the mix from the CPU cooler.

See the Airflow layout image I made if you need clarification:

Now my questions:

1) What is an ideal Intake/Exhaust ratio? (Excluding my cooler I'd be currently ~240CFM-In/104CFM-Out. Unless the CPU cooler ups my exhaust this seems like high positive pressure, no?)

2) Does the exhaust on the "roof" hinder, more than it helps, with my front to back air flow pattern?

3) Would 1 single higher CFM fan at the back in line with my CPU cooler be more effective exhaust system? (Case won't fit a 140mm at this position but could place a 140 on the "roof")

I realize I may be over thinking this air flow thing, but I build so rarely this will likely be the goto PC for the next 8-10yrs. Like to get it right!!! Thanks in advance for any a

 

[UsandThem]

1. Enough to keep your components at the temps you want them to be at, balanced with how much noise you want. I have this case and I use it for Folding 24/7, and the front filters will catch most of the dust.

2. It helps provided you aren't running all your fans at 100%. If you are going to run them at 100% all the time, the top fan is not needed. Having a fan at the top like you show in your diagram is to be able to run both of your exhaust fans at lower RPMs to still move a good amount of air at quieter levels. Your best airflow for that case is to install two front fans in the higher position. This way you will have cool air hitting your CPU and GPU straight on. Having one installed at the bottom like you show in your diagram isn't really needed, and you lose most of it's direct airflow due to the PSU shroud, plus you will lose cool air directly blowing into your CPU area.

3. If your'e not running multiple high-end video cards, you really don't need to run high RPM fans and deal with unnecessary noise. I run my two front fans around 900 RPM, and the exhaust fans around 750 RPM, and my GPU never really gets above 60 degrees Celsius, and that's with pushing it pretty hard with Folding projects.

 

[Furious_Styles]

You're overthinking it a bit. The only thing you really need high CFM/RPM for is radiators. With 2 exhaust and 2 intake you should be just fine on flow as long as you don't run 'em too slow. Try to strike a nice balance with the noise profile vs. fan speed (I typically tie them all to my CPU temp just for simplicity) but depending on your mobo you can figure out a combo that works well for you. I've got a very similar set up to you and I removed the foam piece on the front grille so I get better flow but a bit more noise.

 

[mopardude87]

Glad i ran into this thread,i just purchased this one to replace what i feel is a pretty dated Antec 900 .Prob gonna use at least 3 of the Antec tri cool fans.

Assuming i just got both 120mm and the rear 120mm fans in and on full speed each producing 79cfm,would you guys think it would have comparative cooling to a Antec 900?I could also just fill out all 5 spots and possibly run them on low?

I may even play around with the idea of knocking noise down and adding in 2 front Noctua 140mm fans as well.I like having so many options

 

[aigomorla]

The only thing you really need high CFM/RPM for is radiators.

No this is completely wrong.

The only time you need high cfm is when you need airflow though an unrestricted source.
CFM is how much air is moved, however that number can be seriously hurt when you have restrictions up front. This is why we talk a lot about Static Pressure. Static Pressure is required when you need to either push or pull air though a restriction. This is also why fans with high static pressure tends to cost double the cost of normal fans even without fancy LED's.

And not all radiators are equal, some are optimized for high static, low rpm fans, but those radiators cost as much as an entire AIO unit by itself.



And OP, you dont need to equal air going in with air going out.
Your case is not sealed, so if you have too much air going out, your case will bleed in air.
And if you have too much air going in, your case will bleed out air.

In the real practical world, unless you decide to silicon every nook and krany of your case, you will not achieve negative or positive pressure...

Ahhh i take that back, you can strap on some 1200 CFM blowers to it, and you will probably probably achieve positive pressure, but the results will be dismal as well as deafening for your ears.

 

[Furious_Styles]

I just made a very general comment. I see lots of people getting caught up in this positive/negative static pressure conundrum and I find it useless for the exact reason in the latter part of your post. And being a meshify owner I can assure you it would not be easy to seal it.