EPA compliant woodstoves have a secondary combustion system that
re-burns the combustion gases prior to their release. This is
accomplished with either a catalyst or what are called secondary burn
tubes located immediately below the top baffle (non-catalytic). The
efficiency of these stoves is nearly twice that of a conventional
airtight design (i.e., 75 to 80 per cent) and the amount of
particulate produced is extremely low -- typically in the order of 3
grams per hour.

For a simplified overview, see:
http://www.regency-fire.com/Faq/Wood.php

Cheers,
Paul

On Sun, 16 Dec 2007 22:25:09 -0600, "S. Barker"
wrote:

"epa compliant woodstove"??? You're kidding right? what's to be compliant
about a steel box with a hole in the top?

s