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Newsgroups: comp.sys.amiga.hardware
Subject: Re: The Fanning of the Amiga
Message-ID: <22325@cbmvax.commodore.com>
From: mks@cbmvax.commodore.com (Michael Sinz)
Date: 11 Jun 91 11:20:30 GMT
Reply-To: mks@cbmvax.commodore.com (Michael Sinz)
References: <3004@public.BTR.COM> <43149@cup.portal.com>
Organization: Commodore, West Chester, PA
Lines: 44

In article <43149@cup.portal.com> FelineGrace@cup.portal.com (Dana B Bourgeois) writes:
>[in response to Thad's posting about correct cooling air flow design
>in computer equipment...]
>
>This is perhaps extreme but I think a lot of design teams do not have
>an expert on cooling during the concept phase and if no heating
>problems are experienced during proto-typing I would guess that no
>expertise will ever be called in until feedback from manufacturing or
>from customers causes changes to the design.
>
>HOpefully it is not this bad now.  Hopefully companies take cooling
>into account when designing equipment.  Then again, maybe the need
>ahas gone away with the big heat generators (power transistors,
>tubes, linear power supplies, etc.) and even less expertese is around
>than before.  I don't know.  But echoing Thad, it would be nice (very
>nice!!!) if maintenance in dusty environments were part of the design
>parameters.

If you play with the A3000, you will note that much effort went into the
air flow design.  The hardware guys did a great job with it.

However, air flow is so critical that the A3000 will overheat if the
cover is off.  That is, the A3000 is cooler when it is correctly closed
in its cover.

Air flow is rather interesting.  You can cause a very nice and controlled
air flow by removing air from an area and let it get filled in by air
coming from other areas.  If you select the openings correctly, you
have full control of where the air comes from to equalize the pressure.
Pushing air in does not give you any control.  The pressure will just
grow and it will try to find any easy path out.  The path is changed
due to the turbulance of the fan, etc.

In either case, air flow for cooling is somewhat of a black art.  It
is much like good speaker design:  Many of the parameters are known
but it takes something "extra" to get it really right.

/----------------------------------------------------------------------\
|      /// Michael Sinz  -  Amiga Software Engineer                    |
|     ///                   Operating System Development Group         |
|    ///   BIX:  msinz      UUNET:  rutgers!cbmvax!mks                 |
|\\\///                                                                |
| \XX/     "I don't think so" said Ren'e Descartes, then he vanished.  |
\----------------------------------------------------------------------/