On Thu, 31 Dec 2009 12:05:10 -0800, Larry Jaques
wrote:

On Wed, 30 Dec 2009 20:50:16 -0500, the infamous Ned Simmons
scrawled the following:

On Wed, 30 Dec 2009 10:12:01 -0800, Larry Jaques
wrote:



What burns me up (sorry) is when the tree huggers all use "natural"
wood stoves, buring wood they so often defended. The result is that
they are putting out at least 40 times the amount of CO2 than those of
us who bought high-efficiency gas furnaces.

I've asked you a million times to not exaggerate. If you look only at
the combustion products (which is far from the entire picture), and
make a SWAG for burner efficiency, the CO2 emissions from heating with
wood are perhaps 3-4 times that of gas.

Cite real stats on that, please, Ned.

This looks OK me:
http://www.engineeringtoolbox.com/co...ls-d_1085.html

At 100% efficiency burning wood releases 1.7x as much CO2 as natural
gas. My SWAG is a gas furnace is probably at least twice as efficient
as a wood stove, so 3-4x seems in the ballpark.

Having stood/lived downwind
from a fireplace/woodstove or two, I don't believe a word of it. Whole
valleys are polluted by one single wood fire, fer chrissake. It's
disgusting. I can't work outside when fireplaces are upwind. Catalytic
stovepipe inserts and pellets help for woodstoves, but it's still
lousy breathing downwind of any of those. You'd be hard pressed to
notice combustion downwind of a natural gas furnace.

Plus, everything I've read shows a 25-40x difference. If you have
other stats, show me.

Now you're talking about stuff other than CO2, and I agree. In fact,
I'll bet 40x is way low for particulates when comparing wood and gas.
Wood stoves aren't a problem in that regard here in coastal Maine --
stagnant air conditions are very rare, especially in winter, and
population density is relatively low. But some larger towns have
started to regulate outdoor wood boilers due to their tendency to
smolder and smoke badly when they're damped down. And their short
stacks makes the problem worse because all that smoke is vented close
to the ground.

I did design work about 30 years ago for a company that was building
wood boilers based on a design by a University of Maine ME professor.
The Hill boilers ran full tilt and stored the heat in a large volume
of water. A normal hydronic heating system circulated the stored hot
water between burns. Burning the wood hot and fast resulted in a very
clean burn and pretty high efficiencies.

--
Ned Simmons