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: The present device provides an air duct means disposed between the top end of the heat exchanger of a furnace and the entry port into the flue pipe of the furnace. An electrical blower means is coupled to said duct means to draw hot air therethrough which would otherwise go out to the atmosphere through the flue. The hot air drawn by the blower is redirected to heat, or assist in heating, the building to which the furnace is directing heat, or heat some other facility. An electrical control circuit is connected to the blower means and controls the blower means such that if the furnace is burning fuel, the blower cannot be turned on. The blower can only be turned on after a predetermined time has elapsed from the time that the fuel burning has terminated, so that combustion gases which otherwise would pass through the flue and which might contain harmful ingredients therein, will not be redirected to be used as a source of heat.

Abstract: A fuel saving improvement in conventional home, commercial and public building heating furnaces comprising the inclusion of heat absorbing members such as stones on rod mesh trays in the normally substantial amount of unoccupied space above the furnace combustion chamber. The trays carrying the heat absorbing members are held, one above the other, by a metal support frame resting on the refractory material of the combustion chamber. The stones or other heat absorbing members are each at least three inches in cross sectional dimension and in spaced relation to each other. And the heat absorbing members in each tray are positioned above the respective open spaces between the stones in the next lower tray to cause a tortuous path for the heat and energy passing from the heating flame in the combustion chamber to the furnace flue opening. The heat absorbing members thereby absorb heat from the heating flames which would normally be lost to the flue opening during "ON" periods of the heating flame.

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.

Abstract: A recuperative heat exchanger for a gas turbine or similar source of intermittent heat having an auxiliary heating unit that provides heat to maintain the heat exchanger at a substantially constant temperature when heat being exhausted from the gas turbine varies. Included also are controls that vary the supply of heat being given off by the auxiliary heating unit to compensate for changing operating conditions and provide a gradual heating or cooling of the unit to preclude thermal distortion and structural damage from an unstable temperature.

Abstract: Gas fired air heater for a central heating system comprising a heat exchanger in which are arranged a series of parallel rows of vertical heat exchange tubes, the lower ends of which are connected to a joint burner compartment and the upper ends of which are connected to a joint flue compartment. Two opposite lateral sides of the heat exchanger are connected to air supply and discharge compartments respectively for feeding the air to be heated transversely through the heat exchanger. The lateral air supply and discharge compartments have air inlet and outlet connections at their top and bottom walls only. One of said lateral air compartments is closed at one end and is connected to a fan at the opposite end, whereas at least one end of the other lateral air compartment is connected to a main duct for discharge of the heated air.