Abstract: A fuel-burning forced-air-circulating heating system having a thermostatically controlled heavy-duty blower, and a constantly operating or thermostatically controlled relatively low-powered supplemental air-circulating attachment for forcing air from the cold-air-return plenum to the hot-air-feed plenum of a conventional hot-air furnace. The supplemental attachment bypasses the furnace so that the air-flow resistance of the air filter of the furnace minimizes reverses air-flow through the furnace, resulting in a gentle temperature-equalizing (anti-stratification) circulation of air through the rooms being heated. Preferably, a thermostatic switch located close to a floor energizes the supplemental blower when needed to reduce temperature stratification in the heated space. Alternatively, or in addition, an outdoor thermostat can energize the supplemental blower in colder weather (when its operation is most needed).

Abstract: A fuel-burning forced-air-circulating heating system having a thermostatically controlled heavy-duty blower, and a constantly operable relatively low-powered supplemental air-circulating attachment for forcing air from the cold-air-return plenum to the hot-air-feed plenum of a conventional hot-air furnace. The supplemental attachment bypasses the furnace so that the air-flow resistance of the air filter of the furnace minimizes reverse air-flow through the furnace, resulting in a gentle temperature-equalizing circulation of air through the rooms being heated. Preferably, and very importantly, the supplemental attachment may include a heat-exchanger associated with the furnace flue to further improve the thermal efficiency of the system thus modified.