I have been paying closer attention to the secondary air control on my tarm boiler this year. According to the manual the drier the wood, the more secondary air you need to achieve optimal burn. I have found that increasing the secondary air to achieve an optimal burn also reduced the amount of ash that is produced. As the burn progresses to the coaling stage, more ash is produced if the secondary air is reduced. The manual says adjust secondary air until the flames are just breaking over the front edge of the combustion tunnel. Anybody else adjust the secondary air control as the burn progesses or do you just set it and forget it? Have you noticed any difference in ash production based on secondary air control?