How does the combustion system work in the Endurance, compared to standard boilers?
Standard atmospheric boilers have combustion systems that require both primary air and secondary air for operation. The primary air is introduced through the air shutters and mixed with the gas from the gas orifices. The rich gas/air mixture is then introduced into the combustion chamber through the burners and is ignited by an ignitor of some type (standing pilot, interrupted pilot or hot surface ignitor, HSI). Upon ignition, the flame has an insufficient supply of air (primary air) provided with the gas and obtains the additional air (secondary air) required for proper combustion from the area immediately adjacent to the flame. The primary and secondary air are draft induced by a chimney or in the case of side wall vented boilers by a draft inducer or power venter. The Endurance boiler differs from that type of system and has a premixed combustion system that injects all of the air required for proper combustion with the gas and requires no secondary air. A combustion air blower forc
