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#### Kopi

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I'm on the Noctua site looking at some fans...they claim these specs

Size 120x120x25 mm
Bearing SSO-Bearing
Rotational Speed (+/- 10%) 1200 RPM
Rotational Speed with U.L.N.A. 600 RPM
Airflow 81 m³/h
Airflow with U.L.N.A. 41 m³/h
Acoustical Noise 17 dB(A)
Acoustical Noise with U.L.N.A. < 6* dB(A)

So I'm looking at 17-23dba with how many CFM? I have no clue how to convert that...the relation works out to

1 meter = 3.2808399 feet
1h = 60minute..duhh...

So would I multiply 40, or 80 by 3.2808399 and divide by 60? That gives me like 4cfm.. haha
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#### The Duke

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Does area cubed come to mind

#### Kopi

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No, should it

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#### Kopi

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Its cubed though, not square...
ah thanks tank, so its onyl like 50cfm :<

#### slow'puter

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47.43 CFM = 81 m^3/h

#### The Duke

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Quote:
 Originally Posted by tankman12 http://www.engineeringtoolbox.com/fl...ter-d_405.html
Sweet, you rule

Quote:
 Originally Posted by slow'puter 47.43 CFM = 81 m^3/h
You too

#### t4ct1c47

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Quote:
 Originally Posted by Kopi Airflow 81 mÂ³/h
I hope I worked it out right;

81 x (3.2808399 x 3.2808399 x 3.2808399) / 60 = Airflow 47.67CFM

Kopi

#### Kopi

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Yep, you did it by hand but a machine just told me the same thing...i was really hoping these fans would be near 80 though

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No problem...

#### Sreenath

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Quote:
 Originally Posted by t4ct1c47 I hope I worked it out right; 81 x (3.2808399 x 3.2808399 x 3.2808399) / 60 = Airflow 47.67CFM
yep thats how you do it. its around 50cfm

#### Sreenath

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Quote:
 Originally Posted by tankman12 171612cfm
you multiplied by 60 not divided.

#### tankman12

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Quote:
 Originally Posted by Sreenath you multiplied by 60 not divided.
I realized that. Was doing it in my head before I looked at the site.

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