An electronic control device includes: a flow rate calculation unit that calculates a flow rate of intake air based on an output signal of a flow rate measurement device assembled to an intake pipe; a flow rate correction value calculation unit that calculates an average value, a maximum value, and a minimum value of the flow rate of the intake air, calculated by the flow rate calculation unit, during a predetermined period, and an amplitude of a signal with one or more frequencies equal to or higher than a fundamental frequency of the output signal of the flow rate measurement device and included in the output signal of the flow rate measurement device, and calculates a correction value for the flow rate of the intake air based on calculation results; and a flow rate correction unit that corrects the flow rate of the intake air based on the correction value.

A sealed chimney damper is provided for preventing flow of air between an interior and exterior of a structure through a chimney. The sealed damper includes a damper body having an inlet aperture and an outlet aperture; an upper flange formed around the outlet aperture of the damper body; a valve plate hingedly secured to the damper body adjacent the outlet aperture, the valve plate sized to substantially cover the outlet aperture when the valve plate is in a closed position; and a gasket secured to the upper flange of the damper body and surrounding the outlet aperture, wherein the gasket is positioned between the valve plate and damper body when the valve plate is in a closed position.

A sealed chimney damper is provided for preventing flow of air between an interior and exterior of a structure through a chimney. The sealed damper includes a damper body having an inlet aperture and an outlet aperture; an upper flange formed around the outlet aperture of the damper body; a valve plate hingedly secured to the damper body adjacent the outlet aperture, the valve plate sized to substantially cover the outlet aperture when the valve plate is in a closed position; and a gasket secured to the upper flange of the damper body and surrounding the outlet aperture, wherein the gasket is positioned between the valve plate and damper body when the valve plate is in a closed position.

A furnace including a combustion chamber for burning fuel can have increased fuel burning efficiency, increased heating efficiency, and decreased harmful emissions of combustion byproducts. A combustion air delivery system delivers primary and secondary combustion air to the combustion chamber. Primary and secondary combustion air may be delivered at amounts that increase burning efficiency. An amount of secondary combustion air can be controlled by a valve system. A heat transfer device efficiently transfers heat from products of combustion for heating an enclosed space.

A furnace including a combustion chamber for burning fuel can have increased fuel burning efficiency, increased heating efficiency, and decreased harmful emissions of combustion byproducts. A combustion air delivery system delivers primary and secondary combustion air to the combustion chamber. Primary and secondary combustion air may be delivered at amounts that increase burning efficiency. An amount of secondary combustion air can be controlled by a valve system. A heat transfer device efficiently transfers heat from products of combustion for heating an enclosed space.

A heat source device including a sheet-metal burner body (30), a fan casing (40) connected to the burner body (30), an annular packing (90) connecting a burner-side connection end surface (340) with a fan-side connection end surface (410) in an airtight state, a sheet-metal connection part (80) disposed between the burner-side connection end surface (340) and the fan-side connection end surface (410), wherein the connection part has an opening (85) and a packing storage portion (84) storing the annular packing (90), wherein the opening (85) is provided in such a manner that an opening edge is positioned outside of those of an inlet port (35) and a blowout port (44) in a state where the connection part (80) is disposed between the burner-side connection end surface (340) and the fan-side connection end surface (410).

A method is provided for controlling airflow into a furnace that employs a velocity type damper. In one embodiment, the method for controlling airflow may include engaging a velocity type damper to an air port opening of a furnace. The velocity type damper includes at least one air controlling surface that is positioned proximate to a wall of the furnace at the air port opening so that air velocity exiting the at least one air controlling surface is substantially equal to the air velocity entering the air port opening to the furnace. The method may further include adjusting a cross sectional area through the velocity type damper to control air velocity into the furnace through the air port opening.

A method is provided for controlling airflow into a furnace that employs a velocity type damper. In one embodiment, the method for controlling airflow may include engaging a velocity type damper to an air port opening of a furnace. The velocity type damper includes at least one air controlling surface that is positioned proximate to a wall of the furnace at the air port opening so that air velocity exiting the at least one air controlling surface is substantially equal to the air velocity entering the air port opening to the furnace. The method may further include adjusting a cross sectional area through the velocity type damper to control air velocity into the furnace through the air port opening.

A furnace including a combustion chamber for burning fuel can have increased fuel burning efficiency, increased heating efficiency, and decreased harmful emissions of combustion byproducts. A combustion air delivery system delivers primary and secondary combustion air to the combustion chamber. Primary and secondary combustion air may be delivered at amounts that increase burning efficiency. An amount of secondary combustion air can be controlled by a valve system. A heat transfer device efficiently transfers heat from products of combustion for heating an enclosed space.

A furnace including a combustion chamber for burning fuel can have increased fuel burning efficiency, increased heating efficiency, and decreased harmful emissions of combustion byproducts. A combustion air delivery system delivers primary and secondary combustion air to the combustion chamber. Primary and secondary combustion air may be delivered at amounts that increase burning efficiency. An amount of secondary combustion air can be controlled by a valve system. A heat transfer device efficiently transfers heat from products of combustion for heating an enclosed space.