On Sun, 12 Dec 2004 09:59:17 +0800, Old Nick
wrote:

On Sat, 11 Dec 2004 13:35:42 -0800, Loren Amelang
vaguely proposed a theory
....
- theoretically the same amount of air
through the burner, with 40% as much propane, should give the same
output.
http://www.altenergy.com/propaned.htm

makes sense, and it saved me the trouble....G

Not only have I never reached equal heat output converting from NG to
propane, I've usually run into serious usability issues that forced me
to back off to even lower than maximum possible output.

Anybody out there understand why?

I wonder if it's because propane is _not_ delivered at much higher
pressures. BBQs etc have that regulator that really throttles things
down. You get a propane heating torh that comes straight off the
bottle and it has no trouble with burnback or blowout, and really
belts out the heat. Also I have a propane-based instant gas water
system, and it roars with gas and produces enormous amounts of heat.
Again at a higher pressure, largely letting the orifice do the work.

Standard pressure around here for regulated and piped propane service
is 11" WC. The natural gas service I'm familiar with was between 4"
and 5" WC. Other parts of the world may be completely different...

With a burner designed for propane, it is no problem to get a roaring
fire. And you're right, they tend to make more noise than NG.

Loren