Yes, but no one cares about 75% efficiency.  The little bit I camp in cold weather, I want heat.  I am not trying to be energy efficient when winter camping.

You can replace the orifice to make the 12K BTU model a 16K or 20K BTU model.  The 16K puts out 12080 BTUS, which is what I have.  You can also swap out the blower motor with the 1.8amp motor if you have an older model which I also did.

The older you get, the more you want things done right the first time without getting too hung up on cost.  And you care more about comfort.  So maybe in my next van, I'll try the 2015 model Propex 3500.

--- On Sun, 3/6/11, Karl Mullendore <tdiguru@WESTYVENTURES.COM> wrote:
> Except that the Atwood's "12,000 btu" is input btu, and the
> heater is only 75% efficient, so output (9000 btu) is actually
> less than the larger Propex model.
>
> :-)
> Karl
> www.propexusa.com

> Robert Stevens <mtbiker62@GMAIL.COM>wrote:
>
> >Based on friend's experiences, I can almost assure you
> that you will be
> >very happy you have what you do on your first very cold
> morning camping.
> >There is a HUGE difference in heat production between
> 6-8K BTU and 12! ;-)
>
>
>