dave1949
Super Star Member
Dave, your comment regarding forced convection only applies to previously exempted heaters like the outdoor boilers. Excess air as an emission control strategy was what we had prior to catalytic converters - so about mid 80s technology. It still gets used for cold start on gasoline vehicles. But that alone would not suffice to meet the new standards which are only met by the very best catalytic or secondary air stoves today.
Burning off particulates requires a temperature of 1000F. Thats what it takes to ignite carbon - period. Burning off HC can be done at lower temperatures, but then only in conjunction with platinum or palladium. Secondary air stoves do everything at the same time at 1000F and so the efficiency is reduced due to hot stack temperatures. So it is fairly safe to say that there is going to be a big re-introduction of catalysts and an increase in price accordingly. Whether the next limit can be met by these methods is hard to say.
I see.
I was picturing a typical pellet stove that burns only a little bit of fuel at any given moment, but has a fan forcing air into the fire pot. Pellet stoves are pretty clean burning. It would be difficult to scale that design concept to regular firewood dimensions.