All outdoor furnace systems are closed loop systems
Outdoor heating systems are basically wood fired boilers housed outside of a home. The heat source and the part that has to be heated can be as far apart as a hundred yards. The furnace heats glycol or water where it’s pumped through insulated pipes to your home. The boiling liquid can give heat in several ways such as liquid to liquid heat trading, direct heat, and through a hot air radiator. In a liquid-to-liquid heat trading system, the heated liquid enters a big storage tank containing coils of copper tubing. Water in the tubing is heated and this flows through the hot water system in your home and supplies all your boiling water needs. Direct heat is when heated liquid enters the home, and goes directly into the home’s hydronic system and indirectly heats the boiling water in a separate system. When using a boiling air radiator, heated liquid can be pumped through inside the plenum of a forced-air system. Using the air duct of an existing HVAC system, the radiator transfers the heat to the air which is then distributed by the fans of the furnace when the control component comes on. All outdoor furnace systems are closed loop systems. This means that the cooled liquids return to the heat source via a return tube and then they are reheated once again. Be sure to keep in mind the multiple types of outdoor heating systems that there are and choose the right one based on your specific home needs.