It also occurs to me that a simple thing would be to use charcoal filters
like that of a litter box. these would be thin, and absorb odor from the
outside, readily available and mostly cheap.

http://www.thatpetplace.com/natures-miracle-charcoal-odor-control-universal-litter-box-filter-2-pack

On Wed, Feb 19, 2014 at 1:25 PM, Stuart MacMillan <stuartmacm@gmail.com>wrote:

> Modern cabin air filters are inside the car, downstream from the blower,
> not
> on the intake side.  You might just put screen door mesh on the the large
> mesh factory "filter" and check it regularly in the summer.  It won't be
> bothered by water.  Old school simple solution.
>
> Stuart
>
> -----Original Message-----
> From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On Behalf Of
> Jarrett Anthony Kupcinski
> Sent: Wednesday, February 19, 2014 9:44 AM
> To: vanagon@GERRY.VANAGON.COM
> Subject: Re: fresh air cabin filter
>
> That plastic mesh is, in fact, in place, which is what made the
> accumulation
> of arthropod parts so curious. I actually cleaned out the heater box when I
> had the dash off about seven years ago, so I know it's not decades-old,
> either.  It just occurred to me that if a quantity of bug parts can get in,
> then so can dust, and maybe I could keep things a bit cleaner with some
> kind
> of filter. Modern cars have cabin filters of some sort for this reason.
>
> The challenge (such as it is) is putting filter media like foam or
> fiberglass and getting it to stay in place, considering the force of air
> that the air intake undergoes when at highway speeds. Also, something that
> doesn't just become a water trap when driving in the rain. The Merc link
> that Casey posted is in the right direction, I think.
>
> It would need to be cleaned or replaced regularly, but pulling the front
> grille is far easier than opening up the heater box, imho. Was also
> wondering, if someone has done this, how much did it impact airflow?
>
> -Jarrett
>
> On Feb 19, 2014, at 10:39 AM, Karl Wolz <wolzphoto@Q.COM> wrote:
>
> > There should be a plastic mesh filter in place. About 2 x 18 inches, give
> or take.
> >
> > Karl Wolz
>