THE SETON WOOD BURNING BOILER From 100,000 TO 200,000 Btu' Net output. The key to efficient and clean wood burning is a long turbulent flame path that does not cool until the burn is complete. The Seton boiler has a crossfire flame path over three feet long with a balanced draft and a 99% combustion efficiency. Once the wood is burned cleanly the heat is transferred to the water. To attain the highest transfer efficiency, it is important for the gasses to exit next to the cold return water and the transfer surfaces to remain clean. The Seton Boiler design does this, it combines a self cleaning water tube pressure vessel with a down draft exhaust. The boiler has a combustion temperature from 1,800° to 2,600° and an exhaust temperature below 400°, maintaining thermal transfer efficiencies of 80 to 86%. This boiler does not need water storage to operate efficiently. This is the only wood boiler design that will turn the fire off and hold the wood until it is needed. The combustion process in the Seton design combines pyrolisation with gasification. After fresh wood is loaded into the combustion chamber and the first cycle is complete, the draft closes and the heat from the refractory dries the wood without air and turns the wood into coke.