[SOLVED] non Standard thicker fans performance and noise ?

[nofanneeded]

Hello,

I was thinking about thicker than 25mm fans , in theory they should give more air flow and more pressure at the same rotation speed . why are we ignoring this for our PC builds and stuck with 25mm ones ?

I dont mind 50mm thick fan if it could give better performance at the same noise level.

 

[COLGeek]

For a "thicker" fan to produce the same noise as a "thinner" fan, it will have to turn slower. It may actually still move the same amount of air as the thinner fan as a result.

That being said, standard fan sizes allow for greater compatibility across multiple configurations and components.

I am sure, if you look, you can find some "thicker" fans to experiment with. I suppose you could connect two thinner fans together to get an idea of how large (and cumbersome) a thicker fan would be.

For example:
https://www.amazon.com/DC-Fans-140x140x50-8mm-24V-Fan/dp/B01BKA61C4

 

[nofanneeded]

For a "thicker" fan to produce the same noise as a "thinner" fan, it will have to turn slower. It may actually still move the same amount of air as the thinner fan as a result.

That being said, standard fan sizes allow for greater compatibility across multiple configurations and components.

I am sure, if you look, you can find some "thicker" fans to experiment with. I suppose you could connect two thinner fans together to get an idea of how large (and cumbersome) a thicker fan would be.

For example:
https://www.amazon.com/DC-Fans-140x140x50-8mm-24V-Fan/dp/B01BKA61C4

I wish Noctua looks at it ... and start designing thicker fans .

and you are mistaken about thicker fans need to turn faster to give more airflow , Actually thinner fans needs to rotate faster to give more airflow , and this is known from the 15 and 12mm thin fans .. the opposite of what you said.

Thicker fans have bigger and deeper blades , at the same rotation speed they will move more air.

25mm more thickness is acceptable with today cases that almost all of them take upto 60mm thick Radiators . it is not a big deal ,Also when you dont use Radiators on all the FAN openings , you can place thicker fans there ...

 

[COLGeek]

I wish Noctua looks at it ... and start designing thicker fans .

and you are mistaken about thicker fans need to turn faster to give more airflow , Actually thinner fans needs to rotate faster to give more airflow , and this is known from the 15 and 12mm thin fans .. the opposite of what you said.

Thicker fans have bigger and deeper blades , at the same rotation speed they will move more air.

25mm more thickness is acceptable with today cases that almost all of them take upto 60mm thick Radiators . it is not a big deal ,Also when you dont use Radiators on all the FAN openings , you can place thicker fans there ...

Read what I wrote again. For less noise, it must turn slower. When slowed down, less air flow results. That is what I was stating.

Sure, if the larger/deeper fan turns at the same speed, it will produce much greater airflow AND noise.

 

[nofanneeded]

Read what I wrote again. For less noise, it must turn slower. When slowed down, less air flow results. That is what I was stating.

Sure, if the larger/deeper fan turns at the same speed, it will produce much greater airflow AND noise.

Why more noise if rotating at the same speed ? keep in mind that the fan motor would be also double size and can be made more silent

 

[USAFRet]

Why more noise if rotating at the same speed ? keep in mind that the fan motor would be also double size and can be made more silent

At the same speed, the larger fan is moving more air.
More air = more noise.

 

[nofanneeded]

At the same speed, the larger fan is moving more air.
More air = more noise.

more air = more noise ? not always true .. thats why Noctua fans give better air flow for lower noise compared to other cheaper fans at the same size. blades and motor design plays a role as well.

I just emailed Noctua and Be Quiet .. waiting for their reply on the matter

 

[USAFRet]

more air = more noise ? not always true .. thats why Noctua fans give better air flow for lower noise compared to other cheaper fans at the same size. blades and motor design plays a role as well.

I just emailed Noctua and Be Quiet .. waiting for their reply on the matter

Nothing is "always true".
Well...2+2=4 doesn't count.

In general...more air = more noise.
This is why larger fans can be quieter. They can move the same amount of air at a slower RPM.

And you need to compare apples to apples. Noctua vs cheap junk doesn't count.
To move the same amount of air, a larger Noctua will, in general, be quieter than a smaller Noctua. And the amount of air moved is the key component here.
Fans have but one job....to move air, in an effort to keep components cool.

 

[nofanneeded]

Nothing is "always true".
Well...2+2=4 doesn't count.

I did not say that.

In general...more air = more noise.
This is why larger fans can be quieter. They can move the same amount of air at a slower RPM.

wrong ...

Noctua 15/14 deliver more air flow than Noctua 12 at lower noise level .. so your more air= more noise is wrong. the area of the blades counts as well , the same for thickness , it also gives more area for blades.

you can compare the fan specs on there site ..

having said that , even if they had to reduce the RPM for the double thick fan .. if we get 50% more airflow after that I am happy with it .. remember that double thickness means double blades Area .. this is more than moving from 120 to 140

 

[USAFRet]

I wish you good luck on your experiments.

Please let us know how it goes.

 

[COLGeek]

Blade design has a bit to do with noise and turbulence, as well.

Take a look at CFM vs. noise ratings and speed of fan. The point USAFRet and I are making will become quite clear.

https://noctua.at/en/buying-guide-fans

I use Noctua fans in all of my builds, so am very familiar with their performance.

Also as stated earlier, good luck finding a difference answer.

 

[nofanneeded]

Blade design has a bit to do with noise and turbulence, as well.

Take a look at CFM vs. noise ratings and speed of fan. The point USAFRet and I are making will become quite clear.

https://noctua.at/en/buying-guide-fans

I use Noctua fans in all of my builds, so am very familiar with their performance.

Also as stated earlier, good luck finding a difference answer.

not only blade design .. blade surface area ..

you did not address anything about thickness / noise and gains from thickness VS noise or blades surface Area /noise/ rotation speeds , or blade suface Area /Air flow digits

no numbers no charts , nothing..

and hopefully I will get the right answers ..

 

[COLGeek]

not only blade design .. blade surface area ..

you did not address anything about thickness / noise and gains from thickness VS noise or blades surface Area /noise/ rotation speeds , or blade suface Area /Air flow digits

no numbers no charts , nothing..

and hopefully I will get the right answers ..

I assumed you could do your own research. I don't need convincing to know these things.

https://www.quietpc.com/140mmfans

The Noctua guide provided above should help you understand what we have been telling you.

Take care. I am done here.

 

[nofanneeded]

I assumed you could do your own research. I don't need convincing to know these things.

https://www.quietpc.com/140mmfans

The Noctua guide provided above should help you understand what we have been telling you.

Take care. I am done here.

Nothing you posted talks about Thickness of fans at all . the Noctua provides nothing for they dont even have 50mm thick fans to begin with.

take care ...

 

[prophet51]

There are thicker fans like the one COLGeek linked but they're not specifically made for desktop use so they come with louder motors, I think if a quality pc fan manufacturer made 50mm thick fans they would be better than the 25mm fans.

 

[popatim]

Thicker fans have larger blades = heavier blades which then require a stronger motor to spin those blades at the same RPM as thinner fans.
This usually results in more noise from them from my experience but I'm not tech savy on something as trivial as PC fans.

You should also investigate reverse mounting a second fan to your first. double fans actually do move more air then a single. With one fan spinning in one directing and blowing air out the rear, a second fan mounted behind it spinning in the opposite direction and still blowing out the rear can move significantly more air then the single fan model. This should be easy to fab if you can find a fan that will spin backwards if you reverse the black and red wires (12v & ground) I would use something like a 9v to test the spin and not a live system.

Good luck.

 

[Mtop]

I enjoyed this discussion - Thanks
Would have liked a few more links to backup points.
I just look at specs and price. Lotsa of CFM and low Db on sale, I get spares.