[vdr] Re: Hardware falures

[Stefaan Coddé <Stefaan.Codde@pandora.be>]

----- Original Message -----
From: "Christian Berger" <einStein@donau.de>
To: <vdr@linuxtv.org>
Sent: Tuesday, April 30, 2002 5:14 PM
Subject: [vdr] Re: Hardware falures
> I wonder why my Pentium 90 needs a fan, but my IBook doesn't need one
> and doesn't even get warm. :)

Who says it definatly needs a fan? With everything : try to use something
to transport the hotest surface which is usual small on size....to a much
larger
area.  If this area is big enough then natural convection will be enough to
keep
the temperature low enough. a computer case isn't built according to this
principle
and I wonder why the hell not?
Case manufacturers sure didn't took the time for a thermal analysis on their
product
cause 99.9% of all cases would not pass that test.

I have no idea on the internal setup of an Ibook but it's prolly a
combination with a
low power CPU or somethimes called mobile CPU cause they are used alot in
laptops
in combination with a simple heat exchanger.
This can be a pipe or a plate, in fact.. can have almost any form.
Second.. how big is the harddisk? prolly a 2.5inch which make less noise and
generta less heat
too and power supply... internal or external and how heavy?
What I mean is : there are many places where it's possible to use less for
cooling compared
to a standard computer setup.

> > Tower PC's : too bad, all cards are mounted horizontally which is VERY
bad
> > for heat dissipation.
>
> Well it helps a bit to turn the case upside-down and install a fan on
> one side.

Indeed, such things do help a bit but You add a fan again = extra unwanted
noise.

> Well my problem is how to get out the heat out of the 19 inch rack. I
> currently have a 25 Watts Pabst fan installed getting the air directly
> from outside.

Phew, 25Watts...that's a heavy fan. A fan makes twho different kind of noise
levels:

1) typical humming sound cause by the unstability of the blades.  If used in
a light cheapo
case then those vibrations are amplified by the case.

2) air noise : the air hits alot during it's travel. This generates the
typical 'whoosh' sound.

Try this: remove the cover of the chassis and turn the computer on.
            Measure the temperature and if all stays at a reasonable level
then you can throw
            every system fan away and even think on a noiseless system.
            btw, it's expensive tho. There not soo much difference in price
between a futureclient
            and my media box.... but my media box supports more.