Is this mumbo jumbo or actual spec?

Trojan Horse

Trojan Horse

Trojan Horse

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Been taking a look at the specs of some cooling fans, as I need to pick up quiet (up to 23dBa) fans, also is 20 dba quiet or noisy for 4 fans to run at that speed?

These Alpenföhn 120mm Föhn are actually advertised as
- Sound: 21.0 dB(A)
- Air flow: 59.74 CFM
on: http://www.overclockers.co.uk/showproduct.php?prodid=fg-002-al

this would make them considerably faster and as quiet as the much more expensive corsair sp120 quiet editions?! http://www.corsair.com/en/cpu-cooli...e-edition-high-static-pressure-120mm-fan.html

What are the differences between the fans because the alphenfohn sounds like something I will purchase right away!
 
20 to 23 dba will be nothing to the the human ear.



Decibel Level (dB) Source
140 threshold of pain: gunshot, siren at 100 feet
135 jet take off, amplified music
120 chain saw, jack hammer, snowmobile
100 tractor, farm equipment, power saw
90 OSHA limit - hearing damage if excessive exposure to noise levels above 90 dB
85 inside acoustically insulated tractor cab
75 average radio, vacuum cleaner
60 normal conversation
45 rustling leaves, soft music
30 whisper
15 threshold of hearing
0 acute threshold of hearing - weakest sound
 
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The SP120 are designed for radiator and constricted airflow situations where Static Pressure is of greater value than outright airflow.
For a Fair comparison you're looking at comparing the Alpenföhn against the Corsair AF120 Quiet edition.
Either way the Alpenföhn is cheaper and rated quiter with almost the same Air Flow.
20db is quiet
 
Alright thanks for this,
What is static pressure?

I'm just planning on using 2 alpenfohn's as top intake (or outtake??) and a Lepa Vortex Frame LPVX12P 120mm Fan as the rear exhaust. Do you think that would be best or should I purchase 3 alpenfohns to also take up the rear exhaust.

My other question is, if all three fans are at 20db will I be hearing 60db or 20db?

Also do you have any ideas of how I could block up my bottom 120mm fan slot to prevent dust from entering.

Would it be any use to have an additional 4th fan on the side of the case if the sides are blocked (2-3cm so not completely block) by the cupboard?
 
Trojan Horse said:
Alright thanks for this,
What is static pressure?
Click to expand...

It's basically the pressure the fan can force the air though. High static pressure fans are ideal for use on radiators as there's a restriction there they have to overcome.

Trojan Horse said:
My other question is, if all three fans are at 20db will I be hearing 60db or 20db?
Click to expand...

It doesn't work like that, it'll be around 25db :)

I would take more notice of reviews than specs though. There's no 'standard' to how fan noise is tested.
 
Doesn't OcUK test their fans with some standard? I thought they would...

If possible, give us' a hand and help us' find a review for these things. I can only find reviews for the boost edition
 
If OCUK were to test and review everything we'd never recieve any items in the mail, it would be impossible for them to do it, it's why the customer review section is there for people who have purchased items.
Tbh Alpenföhn are a recognised brand name maker of fans, and for the price I don't think you can go far wrong. The Premium you can pay for some fans like the Noctua, and the Phanteks fans are partly for the name, but mainly for the confidence that the fan does what it's supposed to, and the fact some of us are "THAT" anal over our aircooling and epeen :)
But at £6 compared to £14, I'd go for the cheaper option. But it's your cash and your call, hope this helps
 
I think if OcUK were to test a lot of items in their spec and it would be done all in-house, I mean I understand it would take a lot of time but it would be very useful and probably convince me to purchase from here more often.

Thanks for your help, if the fan happens to be louder than 21dBa and annoying to my ears, is it possible for to return the fans?
 
I have the AF120 on my 480mm radiator that's in the roof of my 900D case. The fans are on top of the rad pulling air in. I've done it like this to keep the loop short, the rad near cool air and so I can have the fans on low speed. They're pretty much silent and I have a lot of voltage through my CPU and it keeps it all cool. :) very very good fans.
 
Trojan Horse said:
Thanks for your help, if the fan happens to be louder than 21dBa and annoying to my ears, is it possible for to return the fans?
Click to expand...

You've got the wrong end of the stick here. Firstly the dB or dBA rating of a fan is essentially a work of fiction. The manufacturers can write whatever number they wish there. Secondly, the irritation caused by a fan is more related to pitch than anything else. 20dB at 15000Hz may drive you insane (think mosquito) while 30dB at 20Hz you wouldn't even notice.
 
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