Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!swrinde!sdd.hp.com!wuarchive!uunet!cbmvax!cbmehq!cbmger!peterk
From: peterk@cbmger.UUCP (Peter Kittel GERMANY)
Newsgroups: comp.sys.amiga.hardware
Subject: Re: The Fanning of the Amiga
Message-ID: <1346@cbmger.UUCP>
Date: 12 Jun 91 09:08:46 GMT
References: <3004@public.BTR.COM> <1339@cbmger.UUCP> <3025@public.BTR.COM>
Reply-To: peterk@cbmger.UUCP (Peter Kittel GERMANY)
Organization: Commodore Bueromaschinen GmbH, West Germany
Lines: 37

In article <3025@public.BTR.COM> thad@public.BTR.COM (Thaddeus P. Floryan) writes:
>In article <1339@cbmger.UUCP> peterk@cbmger.UUCP (Peter Kittel GERMANY) writes:
>>[...]
>>Well, one difference between light rays and air flow is that the path
>>of the former is reversible, the one of the latter not.
>
>Though it's been nearly 30 years since I've taken any course in thermo-dynamics
>(and I've forgotten most of it/them :-), I'd like to cite one practical, real-
>world observation that anyone can verify:
>
>	a fan blowing ONTO a power supply will keep the supply cooler than
>	will a fan sucking air OVER a power supply.
> ...
>Since one of my companies used to make the power supplies  ....

Carefull: the power supply is *not* the main problem. You must equally
take care of the mainboard (high processor speeds mean real heat), RAM
banks, plus everything a user chooses to plug into an expansion slot.
So you have very distributed heat generation where you have to provide
a suitable air flow that really reaches every place inside your case.

>If you want to perform a simple test for yourself, quickly go do some exercise
>and work up a sweat.  Then choose to cool off by either:
>
>	(a) standing in front of a fan blowing on you, or
>	(b) standing behind a fan sucking air around you.

This is a bad analogy. You would have to add a narrow tunnel (the case)
where you're standing in. Then the difference decreases obviously.

>  There ARE quiet fans ...

Oh yes, that inside the A1000 was the quietest fan we ever had. I loved it.

-- 
Best regards, Dr. Peter Kittel  // E-Mail to  \\  Only my personal opinions... 
Commodore Frankfurt, Germany  \X/ {uunet|pyramid|rutgers}!cbmvax!cbmger!peterk