[Mark]

On Jan 12, 10:18*am, bornfree wrote:
On 12 Jan, 10:31, "Arny Krueger" wrote:





"bornfree" wrote in message



On 6 Jan, 13:06, Audix wrote:
On Sat, 05 Jan 2008 12:10:59 -0500, Randy Yates
wrote:

bornfree writes:

How much noise will three 8dB(A) fans make?

About as much as a gnat farting a hundred yards away.

These are REALLY quiet fans - three of them will, at a
maximum, have a noise level that is 12 dB LOWER than the
noise floor in a VERY quiet studio.

Very true!

Don't forget that the 8dB(A) spec is probably utter
marketing bull****. If you can hear one operating 1
metre away it certainly isn't 8dB(A).

I have personal experience of *so called 8dB(A) computer
fans that (when suspended in free air) could be heard 6
metres away in a very quiet domestic room. The room on
its own measured 23dB(A) with a calibrated class 1
precision sound level meter. Fans were of Chinese origin
and were 1500 rpm 60x60mm type.

I have faith. I use one of the 8dbA fans on a daily
basis. They are
made by noctua, an Austrian company with lots of boffins
working for *them.

It doesn't take a boffin to know that if you turn a fan very slow, it won't
make much noise. *Trouble is, it won't move much air, either.

You IGNORANT cynic! The reason these fans are better than any other is
because they shift more air per dbA than any other.

They are, without a doubt the best fans ever made.

Compare and contrast with a similar-sized competitive fans turning at the
same very slow speed.

Noctua make 12cm fans that spin at 800rpm, 1200rpm and 1300rpm. Every
single fan they make pushes more air per db than anything else
currently on the market.

Nothing made by any *other company even comes close.

A 120 mm fan that moves 35 CFM is not news. A normal 120 mm fan might move
80 cfm.

The point here is that the fan pushes 35 CFM while making just EIGHT
dbA. There are no other commercially available fans that move as much
air with as little noise. So do yourself a favour and research the
matter more thoroughly before you embarrass yourself.- Hide quoted text -

- Show quoted text -

Arne is right. It is easy to make a fan that moves a lot of air per
dBa. All you have to do is make the fan BIG and turn it slowly.

If you want a quiet fan, use a big fan that is about twice the size
that you normally need and run it on a lower voltage. It will be very
quiet and will last a long time. Take a 12 Volt fan and put a 12V car
bulb in series with it. It will run slow and be quiet. Use a fan
that is big enough to push enough air even though it is running slow.

Now the trick would be to make a fan that moves a lot of air AND is
quiet AND is small.

Mark