AF120 or SP 10 fans for intake with a dust filter and mesh

charlieklla

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Feb 14, 2014
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I am getting the Corsair 540 case. The case has 2 140mm fans as intake already but I'm getting 3 120mms for the front because they would bring in more air (3 140mms won't fit). While looking at fans I realized that I might need SP fans because of the highly restricted airflow. I watched videos and looked at charts and saw that the cfm of SP and AF corsair fans are almost equal with no restrictions while the SP pulls ahead with a radiator blocking it. I also noticed some people saying the pressure with SP fans are only the blowing side and not the pulling side. There were people suggesting for SP fans and others for AF fans. No definite answer.

Could someone tell me:
1. SP or AF for pulling air through a dust filter
2. What fan do you recommend (doesn't have to be corsair)
 
Solution
My advice would be neither, the case comes with three large, decent quality fans which are likely to be sufficient for any project. Give them a go and see how you get on, it's relatively easy to change things later. Noctua would be a good brand to look at, most of their fans look kinda rubbish but they come with great documentation and performance.

When fans refer to "unrestricted" airflow, they don't usually mean things like mesh or dust filters as these are an incredibly common case feature these days. It really just means where you aren't trying to push air through a radiator, against a component or without a proper intake/exhaust.
Given that Corsair bundles the case with variants of the AF140, it seems pretty clear that they...
My advice would be neither, the case comes with three large, decent quality fans which are likely to be sufficient for any project. Give them a go and see how you get on, it's relatively easy to change things later. Noctua would be a good brand to look at, most of their fans look kinda rubbish but they come with great documentation and performance.

When fans refer to "unrestricted" airflow, they don't usually mean things like mesh or dust filters as these are an incredibly common case feature these days. It really just means where you aren't trying to push air through a radiator, against a component or without a proper intake/exhaust.
Given that Corsair bundles the case with variants of the AF140, it seems pretty clear that they believe it's the best choice, and based on the data available, I'm inclined to agree.

I'm no fluid dynamics expert, but if a fan is capable of producing a pressure on one side, it would stand to reason that the other side produces a negative pressure that is roughly equal. I'm sure there's been a lot of research done on the subject, especially by people doing push-pull configurations on radiators.

Finally, it's really important to make sure you are comparing things fairly. Corsair's data for comparisons does not use fans set to a consistent speed or noise target. Across the board the AF fans run slower and quieter so even though they might produce similar CFM figures, they are doing it far more efficiently. In a real world scenario where you'd probably fiddle with fan speeds to make noise levels more liveable, this is hugely significant.
 
Solution


Sorry for the late reply.
I have heard great things about Noctua fans. I personally would rather buy something cheaper and more aesthetically pleasing, even if they sacrifice a small amount of performance.
So I should stick with the AF series.
Last question. Shouldn't 3 120mm fans push more air than 2 140mm?
Thanks
 
I can't really answer that question, I'm not sure anyone can.

What I can say -
Three 120mm fans have a similar area of coverage to that of two 140mm fans.
This are will obviously be wider for 140mm and taller for 120mm setups (either of these can be beneficial).
At similar noise levels, using comparable fan variants, three 120mm and two 140mm are going to push about the same amount of air.
140mm fans are likely be slightly noisier at similar speeds.
As a general rule, the lower the number of fans in your case the better (this helps with power consumption, cable routing, fan control and noise levels, most systems only need 2-3 fans).

Your two 140mm fans are essentially free, so they are definitely the ones to go with for a start and for that reason alone outperform any possible alternative. If you find that for whatever reason you don't like them, replacing case fans is really easy.
 


Ok thanks.