GUIDELINES FOR FURNACE INSTALLATION
The engine can be installed on virtually any furnace if the combustion chamber is big enough to host the hot side of the heat exchangers. The furnaces can use solid (biomass and coal), liquid or gas fuel.
Gas or liquid fuel furnaces
Those are the one that usually present less problems. The flame is easier to control and “cleaner”. There are no melted ashes and the heat exchangers don’t get dirty from contact with the flame if the combustion is well calibrated. The constant temperature of the combustion chamber makes the exchange of heat easier.
Wood, pellet and chip wood furnaces are all supported. Even reverse flame boilers or furnaces are supported.
Chipwood or pellet furnaces
Are the easiest to adapt to be used with our engines. The fuel provisioning can be controlled so that the heat is generated at a constant pace. They usually come with a burner at the bottom of the combustion chamber, this allows to position the heat exchangers on top of the burner and the ashes to fall on the side and not to stick to the exchangers. It is often possible to find an easy way to position the exchangers on the hot air flow before it reaches the water radiator. It is recommended to first heat the engine exchanger and afterward the water. Sometimes the pellet furnaces may have an external burner, in this case, the heat exchangers can be positioned in front of the flame so that both can be immersed in the flame at the same time.
The positioning of the engine is equivalent to the pellet/chipwood one, but it requires a bit more planning and customization.
Reverse flame furnaces
With those kinds of furnaces the ashes are usually a bigger concern. The wood is above the combustion chamber and the flammable gas generated from the wood is pushed down in the combustion chamber trough a narrow opening under the wood. The problem is that along with the gas, the ashes are also falling down the opening. For this reason it is recommended to not place the exchanger under the gas opening.
The general rule is that the heat exchangers need to be positioned right in the middle of the hot air flow in the furnace. Both the exchangers should receive as much heat as possible inside the combustion chamber. Is important that the entire body of the exchanger reaches a good operating temperature.
Moreover is important to avoid ashes depositing on the heat exchanger’s pipes. Ash deposits reduce the ability of the heat exchangers to conduct heat inside the engine.