modern wood heaters are attaining emission levels far below the EPA limit,
some as low as 0.9 g/k and this shows the level of commitment the manufacturers
have to their designs and manufacturing standards. Always check when buying
a heater that it complies with these standards. There should be a compliance
plate stating brand, model, serial number, efficiency rating and emission
rating (i.e. passed testing
for AS4012 and AS4013) In the past, when we were not concerned about such
things, the air inlet control allowed for almost full deprivation of air to
the firebox and this was often misused resulting in lots of smoke and creosote
build-up because the fire would smoulder not burning off the solids in emission
like it should.
These days the air is regulated so that even on the lowest setting, you will
still have flame and the unit is burning cleanly for about ten hours or more.