Filter material for enclosure vents

[Andrew]

I'm thinking of adding some vents and possibly a fan to a plastic
enclosure of a DC to DC converter to allow heat to escape. Currently
the enclosure is sealed (not water-tight, but splash resistant)
including sealed connectors and a tight fitting lid. It is not
imperative that it is water-tight in any way. It only needs to be
splash and dust/dirt resistant at best.

Obviously any vents and/or fans would compromise the water and dust/
dirt resistance. I figured there must be some material made
specifically for this application (water and dust resistant, yet
allows good airflow) but my numerous searches are coming up short. I
was wondering if you guys have used such a material or can at least
point me in the right direction as far as searching for it?

[Jasen Betts]

On 2008-10-02, Andrew <xxra...@gmail.com> wrote:

> Obviously any vents and/or fans would compromise the water and dust/
> dirt resistance. I figured there must be some material made
> specifically for this application (water and dust resistant, yet
> allows good airflow) but my numerous searches are coming up short. I
> was wondering if you guys have used such a material or can at least
> point me in the right direction as far as searching for it?

you won't find it. water molecules about the same size as oxygen molecules.

replace the case with an alumunium one, aluminium passes heat much
better than plastic, if it's still to hot bolt the hot parts to
the case.

Bye.
Jasen

[Andrew]

On Oct 3, 3:41 am, Jasen Betts <ja...@xnet.co.nz> wrote:

Thanks for your reply.

I figured I wouldn't find anything "water tight," such that no water
could pass whatsoever, but could still pass air. I thought, however,
that I might find something that is not "water tight," that is, it CAN
pass water when saturated, but it would not pass water that is
splashed on it "just a little." For example, if the opening is caught
parallel to raindrops (side of an enclosure 90* to the rain) for a few
minutes while it's removed from the rain, it won't get wet inside.
That sort of thing.

Does that clarification help to bring any materials to mind?

[Jasen Betts]

On 2008-10-06, Andrew <xxra...@gmail.com> wrote:

> I figured I wouldn't find anything "water tight," such that no water
> could pass whatsoever, but could still pass air. I thought, however,
> that I might find something that is not "water tight," that is, it CAN
> pass water when saturated, but it would not pass water that is
> splashed on it "just a little." For example, if the opening is caught
> parallel to raindrops (side of an enclosure 90* to the rain) for a few
> minutes while it's removed from the rain, it won't get wet inside.
> That sort of thing.

possibly raised aluminium mesh might work for you, if you mount it
the right way up the slopes formed during expanding will act as louvres.

also louvre ventilation plates can be had from some hardware suppliers.

Bye.
Jasen