Well, after filling the cylinder it ran for 4 hours on low. The 20lb cylinder was at ambient outside temp as was the little 1lb cylinder. I did not weigh it unfortunately, but I'm suspecting because of not following the clear directions to freeze the 1lb cylinder first, I probably only got a 2/3 fill. Based on my seat of the pants method, I am content with my findings of time and claims by Mr. Heater. I would also llike to tell Alistairs wife that he is awesome. :-)
Courtney
(Who's wife is NOT finding him awesome these days) (No kindling again for her morning fire!!) :-}

----- Original Message -----
From: Edward Maglott <emaglott3@GMAIL.COM>
Date: Monday, November 8, 2010 5:29 pm
Subject: Re: Actual burn times with Mr Buddy MH9B (Little Buddy)
To: vanagon@GERRY.VANAGON.COM

> Wow, that is impressive Alistair.  I forgot all that
> chemistry years
> ago but you make is look easy.  Can you calculate BTU
> produced in
> there somewhere?  How many BTU is the little buddy rated?
>
> Refilling propane cylinders: I have several that I refill.
> I weigh
> them empty and write the tare weight on them.  Freeze, refill,
> re-weigh.  If you freeze them, you can get more propane
> into them.  I
> have found by experimentation that filling from the 20# tank
> into the
> frozen to 0 degrees F little tank, it will take just about the
> correct amount.  I usually stop the filling process when I
> can't hear
> fluid movement anymore.
>
> Edward
>
> At 04:39 PM 11/8/2010, Alistair Bell wrote:
> >aha! its an opportunity, not to answer question, but to work
> out just
> >how much water vapour is produced by burning the 1 lb bottle of
> propane.>
> >lets make assumption that no CO is produced, ie the heater is working
> >perfectly, and that there are 16 oz to the lb, or 454 g.
> >
> >combustion equation:
> >
> >C3H8 + 5O2 ----->  3 CO2  + 4H2O
> >
> >so we see for every mole of propane burned, we get 4 moles of water.
> >
> >molecular weight of propane = 44 g/mol
> >
> >moles per 1 lb bottle = 454/44 = 10.3 moles
> >
> >therefore burning the entire bottle would produce 4(10.3) = 41.2
> >moles of water
> >
> >molecular weight of water = 18 g/mole
> >
> >therefore 18(41.2) = 741.6 g of water produced.
> >
> >almost 3 cups of water into the van in 6 hrs.
> >
> >
> >alistair
> >
> >
> >
> >
> >On 8-Nov-10, at 12:16 PM, Courtney Hook wrote:
> >
> >Just hauled out my little Buddy Heater and it claims 6hrs on
> low with
>