Karl, we have a Propex Furnace (from Tom Forhan's group purchase). Your
experience is about the same as ours. We have added an bubble pack insulation
to the poptop and keep it permanently closed in the winter. We have also added
heavy winter carpeting and camp with out curtains closed to provide a dead air
space next to the glass.
In our experience, you can expect about the same heating from the Propex
Furnace as your can get using a 120v 1500 watt cube heater. We have on occasion
used both together.
-Larry
'86 Syncro Westfalia

Karl Mullendore wrote:

> Could anyone using a Propex (not Carver) furnace relate how well the unit
> heats in really cold weather? I suspect that mine is not operating quite up
> to snuff, i.e. in 15 degree F. weather it keeps the interior at 55-60 max
> running full time, at 0 F. only 45 F. Help! Do I need more furnace, or just
> to wait till I reinsulate the van this summer? Thanks for your input!
>
> Karl M