I have a solar panel and a propex....unfortunately, I do not know much
about the specs of the panel as far as power out-put.  It is about
2'x3'...silicon chips imbedded in blue fiberglass.  Under full
sun-light, it puts out about 2 to 2.5 amps max.  Under ideal winter
conditions (no clouds), this is enough to re-charge the battery for a
full nights use of lights/propex at moderate temperatures....for me,
that is.  There are so many variables here, it is hard to generalize.

The propex is a power hog relative to anything else you are likely to
run.  I have an optimus aux battery.  I also have a plat-cat portable
catalytic heater I use in extreme weather.  The cat only draws .5 amp
hour.  When it's below say 32 f., I use the plat cat as the main heater
(running pretty constantly) with the propex cycling on and off as a
booster.  With this set up, I have camped at -6 degrees f.  Starting
with a fully charged aux battery, I had no problem keeping the van 65
degrees f. inside...and using lights, radio, etc. and still having
plenty of power in the morning.  With the heavy usage at these temps,
though, after a few days, the solar charger cannot keep up.  If i had
relied on just the propex without the cat at these temps., I doubt I
could rely on MY solar panel for even 1 day....probably have to start it
up for a bit to charge the battery enough to continue to make it through
the nights with heavy power draw.

So, get as much solar power as you can afford and/or carry.  I do not
know what's out there.  My panel may be old and not as efficient as the
new ones.  Let me know what you learn.

As Mark mentioned, Insulation is critical.  I use the alumnium covered
bubble wrap as window and roof insulation.  It's great stuff....just cut
slightly larger than the window, and you stuff the excess in along the
window frames....it stays there by itself...makes the van look like a
lunar lander from the outside....plus....darkness!...your van will be
dark as a closet at high noon in the desert.  You can get the stuff at
Orchard supply warehouse and similar places.  I posted a detailed
description on this back in dec or Jan.  It's $98 for a roll large
enough to do all windows and the pop-top....insulate all the canvas
walls.  At really cold temps, though, you will likely want to top
down....and lower the upper bed before closing the top...adds
insulation....you will still have about a 3 foot section of exposed
fiberglass....cut a piece of insulation for this...it makes a
difference.

p-mail for more info.
steve

Benjita wrote:

> Hi all,
>
> I have a Propex Carver P4 on its way to me.  I am planning on adding a
> solar
> panel to the roof to power the sucker.  So, in order to estimate the
> size and
> power of the panel I will need, I would like to hear about other
> members
> experiences with the Propex.  Basically what I would like to know is,
> at a
> given temperature the Propex' fan was on %50 of the time. Or at 20
> degrees the
> fan ran continuosly.  Is there anyone out there with a solar panel
> that could
> make a suggestion as to adequate size.  For me the heater fan will be
> the
> greatest draw.  Thank you for any and all replies.
>
> Cory
> '86 Syncro Westfalia