2 fans stuck together or a thicker fan?

Mr Fujisawa

Mr Fujisawa

Mr Fujisawa

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18 Oct 2005
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661
Just wondering, would I be getter to attach 2 apache blacks together (kind of like push pull except no rad inbetween) to increase airflow from my intake, or better to get a thicker fan (38mm like the ultra kaze). Noise is a factor but i need more airflow from my intake!

thanks
 
Thicker fans do 2 things. They increase airflow and increase static pressure when compared with thinner fans of the same design and RPM.

A number of things can be done to improve airflow:

1. Increase RPM
2. Increase fan depth
3. Direct airflow to the hot parts of the computer. Some people produce getto baffles from ceriel packets - but be careful it doesn't get hot enough to set anything on fire!
4. Choose a fan better at airflow for a given level of noise/backpressure
5. Remove backpressure normally done by cutting away un-needed metal from the case that the resticts airflow - be very careful of sharp edges, make sure you have safety equipment e.g. hand, eye, breathing and ear protection

For case fans I would expect low backpressure (unless the case has a very restrictive mesh covering the intake). For case fans I would consider scythe's very impressive slipstream series of fans which are poor at handling backpressure but produce a large amount of airflow in unrestricted environments for a given level of noise.

I know this doesn't help the OP who has already purchased a fan, but others may find this useful.
 
Chris Beard said:
Thicker fans do 2 things. They increase airflow and increase static pressure when compared with thinner fans of the same design and RPM.

A number of things can be done to improve airflow:

1. Increase RPM
2. Increase fan depth
3. Direct airflow to the hot parts of the computer. Some people produce getto baffles from ceriel packets - but be careful it doesn't get hot enough to set anything on fire!
4. Choose a fan better at airflow for a given level of noise/backpressure
5. Remove backpressure normally done by cutting away un-needed metal from the case that the resticts airflow - be very careful of sharp edges, make sure you have safety equipment e.g. hand, eye, breathing and ear protection

For case fans I would expect low backpressure (unless the case has a very restrictive mesh covering the intake). For case fans I would consider scythe's very impressive slipstream series of fans which are poor at handling backpressure but produce a large amount of airflow in unrestricted environments for a given level of noise.

I know this doesn't help the OP who has already purchased a fan, but others may find this useful.
Click to expand...

My 1 intake does have a dust filter and a futher plastic cover (its an antec p180 case). Dunno if that would be considered restrictive.

How do I know if there's high backpressure? bit of a noob with that tbh!

EDIT: also, would you know fi the ultra kaze would work out better in my case or the slip stream 1900?
 
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Skinnee labs testing showed an improvement in static pressure from stacking yate loons with nothing inbetween, much to my surprise. This won't help airflow, as covered above.

If you had two fans stacked but turning in opposite directions you could get a great deal of airflow, google "counter rotating fan". This wont work if you take two of the same fan and reverse the polarity on one, as the blades are swept forwards to improve performance. You'd been one made to turn in the wrong direction. In practice these fans tend to be about 55mm thick and have both sets of blades and hubs already fitted.
 
JonJ678 said:
Skinnee labs testing showed an improvement in static pressure from stacking yate loons with nothing inbetween, much to my surprise. This won't help airflow, as covered above.

If you had two fans stacked but turning in opposite directions you could get a great deal of airflow, google "counter rotating fan". This wont work if you take two of the same fan and reverse the polarity on one, as the blades are swept forwards to improve performance. You'd been one made to turn in the wrong direction. In practice these fans tend to be about 55mm thick and have both sets of blades and hubs already fitted.
Click to expand...

Always wondered how easy it is to reverse the direction of a fan, do they work if you swap the + and - over?

Never been brave enough to try it on a PC, guesse you cant do much wrong with just a power supply though.
 
@Danm54 If you swap the +/- over I'm pretty sure the fan will indeed spin the other way, that's what I meant by reversing the polarity. However the blades aren't symmetrical, if spinning backwards they wont move anything like as much air. I'm not sure what happens if you do this anyway, airflow should still be better than one fan alone but I think you'll kill the less effective fan. Might have to try this.

@ Strawberry Then the second one would still have the blades facing the wrong way and they'd both be spinning in the same direction.
 
Here's an example of what I was talking about, the san ace 9CR1212G002. Datasheet here. 480Pa of static pressure.

To put that into context, my 38mm san ace is this one and offers 70Pa of pressure. So that beast will force lots and lots of air through very high fin density radiators, probably though several of them.
 
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JonJ678 said:
Here's an example of what I was talking about, the san ace 9CR1212G002. Datasheet here. 480Pa of static pressure.

To put that into context, my 38mm san ace is this one and offers 70Pa of pressure. So that beast will force lots and lots of air through very high fin density radiators, probably though several of them.
Click to expand...

Thats quite good, im thinking the reason this hasn't took off is the noise, 70db!!!!!
 
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