Case Fan questions: 120 or 140?

[neowing]

Sometimes ago, I just get question about case fan.

If I have a middle tower case that can install the case fan of [size] 120 or 140,
Which size is the best ?

Defending of the computer case size, what do I need to know ?

 

[neowing]

I research myself about "How to choose Case Fan".

You have to look at 4 conditions.

First of all, the Case Fan must be quite:

If the case fan noise is "0 dB [Decibel]", It mean "weakest sound heard".
If the case fan noise is "30 dB [Decibel]", It mean "Whisper Quiet Library at 6′ "
If the case fan noise is "60 – 65 dB [Decibel]", It mean "Normal conversation at 3′ "
If the case fan noise is "80 dB [Decibel]", It mean "Telephone dial tone"

Above information found in following link:

http://www.soundtherapytechnologies.com/decibel-comparison


Second, You have to research "RPM."
RPM is "the revolutions per minute a computer case fan or heat sink fan spins."

With a high RPM, the fan will move more air or remove more heat from the computer or processor. However, keep in mind that as you increase the RPM of a fan the noise or decibel (dBa) also increases.


Third, You have to research "CFM"

Short for "Cubic Feet per Minute", CFM sometimes abbreviated as CFPM is the air flow measurement used when describing how much air a fan or computer case fan is capable of distributing.

The higher the CFM the more air the fan is capable of distributing, 70 CFM or more is a good starting value. When looking at the CFM it's also important to look at the fans dBA, smaller fans with a higher CFM makes more noise.

1 CFM = 0.02832 m³/min
60CFM = 1.6992 m³/min


Personal Note 1:

I searched the information, but when I buy the case fan, I didn't think about CFM and the case fan's input power.



Forth, Find the Case Fan connector type.

There are 4-pin / 3-pin / or other [unknown].

When you are going to build your computer, the computer case might have Top/Front/Rear fan connector with controller on the case or the Mainboard might have 1 or 2 of CHA_FAN.

I am not sure where you will connect your fan so, I cannot help you.
If you ask me where I connect my Fan connector, my computer case have its own controller.


But I cannot find a good information about size difference. [ 120mm / 140mm ]


If you know what is the differnt between [ 120mm / 140mm ],
Could you sharing information ?

 

[delrey]

https://www.newegg.com/Product/Prod...1|35-181-050^35-181-050,35-181-053^35-181-053

See above for a comparison between a 140mm and 120mm fan. Both fans are similar in the sound level but RPM's and flow (CFM). The 140mm has slightly higher CFM. 120mm is more common so I would double check to see if your case supports 140mm before buying.