i have either spoken to or corresponded with many stove manufactures over the past two years or so. i have been looking for a small air tight wood stove around 4-5 kw output, around 20k BTU plus or minus (these are quite common in the UK). by and large they have all told me to pass emissions in US/CA you need to have the small stove run hot. with the air controls featured to quiet the stoves output, as a user would want, would negate the ability to pass EPA particulate emissions. this is also somewhat true of larger stoves. that is all stoves burn most efficiently at at least 80% rated output continuously. therefore it is best for the environment to buy a small stove, and stoke it often. most consumers in the US don't want to do that, and no stove will burn all night like with the air controls opened up like that.
as far as i know the navigator stove works stoves are not air tight models.
a small stove has a harder time keeping the chimney gases hot enough. andrew mentions creosote build up and that will certainly occur if you stove is not hot enough and does not have a large enough bed of coals in it before you dampen it down. a stack themometer is valuable here.
i think it is well known that wood stoves require stoking in the 4-6 hr range. if you want 12 hr burn times you should be burning hard coal. that will do that no trouble at all.
