question about Cooling fans and negative pressure.

[MuricanGamer]

Hey guys, so i'm building my first gaming rig and I've recently come across the negative/positive pressure conundrum. My question is: should I get two low CFM fans (in the 50-70 range) and 2 high CFM fans (100-200 range) my theory is, in doing this it will keep negative pressure flowing through out the case, or am I just reading too much into this and try and keep all the fans in my case around the same CFM? if the latter is so; would the Arctic F12 be pretty good? Last but not least, are the rubberized fan mounting rivets worth getting? I only ask since they are supposedly great at eliminating vibration within the case.

http://www.amazon.com/gp/product/B00NTUJRHK?psc=1&redirect=true&ref_=ox_sc_act_title_2&smid=A2T6N244WTLWGU

ARCTIC F12 - Value Pack (5pc) - 120 mm Standard Low Noise Case Fan

Specifications
Dimensions: 120 (L) x 120 (W) x 25 (H) mm
Fan: 120 mm, 1,350 RPM
Airflow: 74 CFM / 126 m³/h
Bearing: Fluid Dynamic Bearing
Noise Level: 0.3 Sone
Current / Voltage: 0.25A / +12V
Weight: 107 g

6 Year Limited Warranty

 

[basroil]

Pressure doesn't flow, only air itself does.

If you are trying to achieve positive pressure (reduce dust buildup), you'll want to worry more about the static pressure than maximum airflow. Nothing can really be said though without knowing the case being used, since if you have a mesh type case, no amount of fans will help

 

[synphul]

I think you're overthinking it a bit. So long as you have solid airflow replacing the air in the case with fresh, steady air in/air out you should be fine. You may want static pressure optimized fans with slightly higher cfm as front intakes especially if you have a mesh filter up front. For the purposes of overcoming the air restriction of the filter and blowing past any hdd trays/cages usually up front. Rear exhaust fans aren't typically filtered so don't fight with as much restriction.

I've used the rubberized isolators in the past with pretty good results. My current case I was unable to use them because the fans mount in slots rather than holes so they're currently hard mounted to the case but no ill effects or vibrations. I think if a fan is that out of balance to cause vibration noise those rubber/silicone isolators are more of a band aid for a poor quality or defective fan.

Those f12's should be decent, 74cfm is pretty good airflow. Trying to get much more out of a 120mm fan is going to come at the cost of higher noise (aka the jetflo 120's).

Just as pressure doesn't flow, fans in a ventilated case don't create pressure either. The air will follow the path of least resistance so there's only airflow. Pressure would indicate air pressure strong enough to create pressure and a container that was otherwise sealed. If it was a matter of high pressure (air hose or similar) pumping in forced air into a container with a tiny pinhole some pressure may be possible but only due to the vast differential. Assuming you had awesome static pressure fans pushing 10mm/h2o static pressure that equates to 0.014 psi. Even an air hose pushing 130psi wouldn't cause the sides of the case to bulge because of all the places for air to escape so no pc case fans stand a chance at produce 'pressure' other than static air pressure moving past/through an object (such as a radiator or other obstruction).

 

[MuricanGamer]

Hey guys thank you so much for feedback it reminds me that i still need to do some research, the case i'm getting is the Carbide Series® SPEC-01 Red LED Mid-Tower Gaming Case ( http://www.corsair.com/en-us/carbide-series-spec-01-red-led-mid-tower-gaming-case ) I got it because it had the best reviews and price for an entry level case.

I've read about the static pressure optimized fans although I cant remember where I need to check those out too.

P.s. Also to Basroil's post, I thought positive airflow meant more cool air is flowing than warm air flowing out? don't you want more warm air to flow out than cool air coming in, that way you get a consistent cool-to-warm air flow ratio?