I've been running my AC that way for 10 years now. If you run the AC fan at a lower setting more of the cold air stays in back.
I would never go back to having the plenum installed, though not having it gives the AC box an 'industrial' look.

-- Thomas

On Friday, August 24, 2012 at 12:40 , Derek Drew wrote:

> There are threads probably on here and at Samba where people are
> taking the Westy overhead-of-the-rear-seat air duct (usually beige)
> off the front of the A/C, something people seem to call the plenum
> because it sounds cool.
>
> Here is a great thread on
> it:
> <http://www.thesamba.com/vw/forum/viewtopic.php?t=424773&postdays=0&postorder=asc&start=0>http://www.thesamba.com/vw/forum/viewtopic.php?t=424773&postdays=0&postorder=asc&start=0
>
>
> My question is about the practicality of doing this with respect to
> the rear passengers.
>
> Has anybody tried using a plenum-less setup where passengers were
> actually sitting in the back seat????
>
> What I am wondering about is whether the most important original
> purpose of the plenum was to direct the cold air forward so it
> wouldn't blast onto the occupants of the rear seat and have them
> revolt or put on winter coats and hats.
>
> I get complaints as it is from the people in the back that it is too
> cold back there. Maybe VW felt that nobody would be able to sit in
> the back seat if they didn't have something to duct air over their heads.
>
> At 10:48 AM 8/16/2012, TJ Hannink wrote:
>
>
> > Can the blower fans for the heater/defroster be used for the
> > airconditioning evaporator?
> >
> > The part number for the front unit is 251 819 015 while the one for
> > the A/C is 321 820 015.
> >
> > Physically they look the same and they are both rated at 300 watts.
> > The only physical difference I can see is the electrical connections.
> >
> > One online parts vendor told me no, they are not interchangeable,
> > another vendors website says that they are.
> >
> > Thanks in advance,
> >
> > TJ Hannink
>
> _______________________________________________
> Derek Drew
> Washington DC / New York
> derekdrew@derekmail.com (mailto:derekdrew@derekmail.com)
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>