Thick fans vs thin fans

[Vince604]

What is the difference between the thicker and thinner fans?
I was trying to compare the manufacture specs of a 92x92x25mm and 92x92x32mm fan and it seems as the 92x92x25mm fan has a better air vs. noise ratio.

Can anyone explain to me the difference between the two?

 

[CaptainNemo]

Thicker fans push more air because the deeper blades are able to scoop more air; the extra noise vs a slimmer fan is probably due to drag.

 

[Vince604]

Okay but wouldn't it be more convient to get a thinner fan to push more air than a thicker one yet have a lower dbA?

 

[namek0]

Personally I'd rather go for the thicker fan with lower dec and greater air flow. Generally the thicker ones are cheaper anyway

I had a Fortis jet engine cpu fan once, I had it on for 2 weeks or so. When I slapped on my Volcano, I was amazed at how much quieter it was. This is off topic a little, since the Fortis was a higher rpm fan and all, I'm just saying that I prefer a quieter fan. Don't get me wrong though, it still keeps my o/c athlon nice and cool

It's all good ^_^

 

[Vince604]

Is there any fans like that? I mean the thinner fans push more air and at a lower dec. then thicker ones.

 

[lhgpoobaa]

i dont think so.
most standard fans have 5 or 7 blades. being less thick the blades are less angled or thinner, reducing airflow.

With very low profile fans more blades are often introduced to offset the loss of airflow.
But more blades means more turbulance and thus more noise, so the answer is no.


<b>My Computer is so powerful Sauron Desires it and mortal men Covet it, <i>My Precioussssssss</i></b>

 

[lhgpoobaa]

also, the 32mm thick fan you mentioned, does that one come with fixed stators like the delta focussed flow fans?



<b>My Computer is so powerful Sauron Desires it and mortal men Covet it, <i>My Precioussssssss</i></b>

 

[Vince604]

I'm not sure what fixed stators is?
I was comparing two fans from the Papst catalogue I downloaded.
I asked you on another post to which company was better and you picked Panaflo for lowspeed fans and Papst for higher speed ranges (2500+) rpm. So I won't be replying on that one as I might as well do it here.

Well I probably will be getting a Papst but should I get a 32mm thick one or stick to a 25mm thin one?
The 25mm thin one has 7 blades in the picture I see while the 32mm thick one has 5 blades.

 

[lhgpoobaa]

fixed stators are like fan blades that point the other way and dont move.
Air comes out of the fan in a spiral fashion, and the stators even up the airflow so its straight and 'focussed' apparently improving the flowrates.

well from whay you have said the thicker fan has sacrificed 2 blades, and typicically less blades equals less noise, so i would probably get that one.

<b>My Computer is so powerful Sauron Desires it and mortal men Covet it, <i>My Precioussssssss</i></b>

 

[Vince604]

Oh okay I get it. But I don't think I have seen any fixed stators on fans before? Do you know of any specific fans with fixed stators?

Less blades less noise but it seems to not apply to the thicker fans. Here's a comparison of two fans.

92x92x25 36dbA 55.3 CFM 3000rpm 7 blades
92x92x32 37dbA 47.1 CFM 3000rpm 5 blades

It's quite obvious that the 92x92x25 has a better overall airflow and noise ration vs the 92x92x32. That's what I don't understand. Unless Papst made a mistake in the specs. of their catalogue but I don't think it is.

You have any idea what's going on?

 

[lhgpoobaa]

hmmm. those numbers are most strange... one wonders why they make the 5 bladed fan at all.

there are only a few fans that have 'stators' the volcano series and the delta 'focussed flow' screamers, both high flow fans and 38mm tall at least.

<b>My Computer is so powerful Sauron Desires it and mortal men Covet it, <i>My Precioussssssss</i></b>

 

[svol]

Well my Delta HP120mm fan has them... but it is 4000rpm (197 cfm) and very loud so i slowed it down with some resistors.
It needs 36W though.

My dual-PSU PC is so powerfull that the neighbourhood dimms when I turn it on

 

[Vince604]

That's exactly what got me confused. Less blades are suppose to be less noise! But it's not looking that way.

Oh I think I found them. They have like dual blades on them.

 

[lhgpoobaa]

maybe a link to pictures may help us.

<b>My Computer is so powerful Sauron Desires it and mortal men Covet it, <i>My Precioussssssss</i></b>

 

[Vince604]

Sure.
It's a PDF document on the Papst site for the 92mm fan series. Just compare any of the fans on the first page with the last page.
<A HREF="http://www.papst.de/pdf_dat_e/S20gb.pdf" target="_new">http://www.papst.de/pdf_dat_e/S20gb.pdf</A>

 

[lhgpoobaa]

hmmm. i dunno. im not seeing any dual bladed fans.
honestly it doesnt matter. just go with the best one.

<b>My Computer is so powerful Sauron Desires it and mortal men Covet it, <i>My Precioussssssss</i></b>

 

[Vince604]

Oh the dual blade fans is here:
http://www.deltaww.com/products/dcfans/dualblade.htm

the post before was about comparing the thick and thin fans.

 

[Vince604]

Oh the dual blade fans is here:
<A HREF="http://www.deltaww.com/products/dcfans/dualblade.htm" target="_new">http://www.deltaww.com/products/dcfans/dualblade.htm</A>

the post before was about comparing the thick and thin fans.

 

[lhgpoobaa]

yer i know of them... though i didnt think pabst did em. just delta.




<b>My Computer is so powerful Sauron Desires it and mortal men Covet it, <i>My Precioussssssss</i></b>