The main advantage of ABC ROLO furnaces is the fact that the combustion is aided by the regulation of primary and secondary air. Primary air is brought into the lower zone of the furnace below the grate in the furnace and provides a rapid rise in the temperature of the furnace during the fi ring phase. Secondary air is brought into the upper zone of the furnace and supplies the fi rebox with a certain amount of heated air necessary for the complete combustion of the gases released during the burning of the wood.
Secondary air has another role to play, which is to prevent soot buildup on the fi rebox door glass. This means that full combustion is ensured at all times (there are two levers in the lower part of the furnace that are used for said regulation).