Caluculate Cooling with Fans

[jeremiahlandi]

Hello [H]ard|Form,

I was wondering if someone had a calculator or could point me in the direction of a formula to calculate CFM.

I have read that multiple fans inline can increase CFM but only slightly. What I am looking to do is replace a 120 mm intake fan (http://goo.gl/gvG77w) with comparable intake fans that are smaller(mayhbe 4 60mm…).

Right now it is a single point of failure, I figure if I switch it out with several smaller ones it would have less chance of a catastrophic failure.

Let me know what everyone thinks on my logic and the formula. I want the four fans to add up to about 260 CFM so I am thinking it is just straight CFM addition but I dunno 

 

[zaniix]

your logic is flawed, small fans suck.

 

[Ryankirsch13]

Fans don't generally fail, and when they do, you tend to not only hear it, you can easily see it. I would never use anything smaller than a 120mm fan unless I have to. Anything smaller than that doesn't move much air and can tend to be loud. Grab a high quality 120mm fan as that's the best it may possibly get. Don't go by manufacturers CFM readings either, they aren't usually accurate and don't tell you how well the fan performs under certain circumstances, nor do they depict real world performance in most cases

 

[doyll]

What's been said above.
What you want to see is the P-Q curve of fans from an independent test source. I'm not suggesting any fan in perticular, but here is the P-Q curves of several fans to give you an idea of how manufacturers' published specs relate to actual airflow. 0.5-1.0mm H2O is representative of resistance caused by case vent and filter. If I had to choose from these, it would be the AP-15 or Glide Stream.

 

[jeremiahlandi]

Thank you everyone!