Blue Eyes wrote:

> <<Now, if you feel the flue gas output of a typical precipitating
> furnace, you will notice that it's about as warm as dish washing
> water.  That's cool enough to capture much of the available phase
> change heat.   In our non-direct vented catalytic heater case, all
> that additional heat gain goes into the van which is the heat
> exchanger, whereas the direct vented type wastes it.  <<...>>  So, for
> pure heating value per pound of fuel, I'm very confident that the non
> direct vented style is more
> efficient.>>

I'm not sure this is true.  The exhaust does heat the exhaust tube, which
radiates some heat into the van.  Also, with the non-vented heater, you
have to open the windows...or 2 of them anyway.  That causes more
heat-loss than the exhaust tube i would venture.  It's a much cruder and
less efficient exhaust system than the closed and controlled system on the
plat cat.
steve