A method of operating a heating device includes heating air in a heating device chamber. The method further includes exhausting outgoing air from the heating device chamber via a first flow path through which the outgoing air flows in a first direction, and supplying incoming air to the heating device chamber via a second flow path through which the incoming air flows in a second direction opposite to the first direction. The latent heat in the outgoing air in the first flow path is transferred to the incoming air in the second flow path thereby condensing water vapor contained in the outgoing air to produce liquid water.

A fireplace system can comprise a firebox and a heat exchanger. The heat exchanger may be in fluid communication with ambient air and may comprise an inlet configured to draw air into the front of the heat exchanger. Operation of a fireplace system comprising a heat exchanger may produce airflow through the heat exchanger by natural convection. The airflow through the heat exchanger may reduce heat transmission from the firebox and the fireplace system.

A combustion device includes a body defining a firebox, a viewing window in front of the firebox, an upper plate adjacent to a top side of the firebox, a first air passage extending from an end adjacent to a rear end of the body to a second end adjacent to a front end of the body, and a second air passage adjacent to a back side of the firebox. The second air passage has a communication opening at an end communicated with the firebox. The communication opening is at a height higher than a height of a bottom side of the firebox and lower than a height of the top side of the firebox. A burner is disposed within and adjacent to the bottom side of the firebox.

A high efficiency wood burning furnace assembly includes an internal firebox having a door positioned therein to access an interior of the internal firebox. An exhaust throat extends through an upper wall and a grate is mounted in the internal firebox and is spaced vertically above a lower wall. A primary diffuser is mounted within the internal firebox and is positioned adjacent the front wall and the grate. A primary air supply is in fluid communication with the primary diffuser to supply air to the primary diffuser such that the air is released along an upper surface of the grate. An air conduit is mounted in the internal firebox and extends upwardly from the primary diffuser. The air conduit releases air vertically above the grate and the primary diffuser. A front wall of the internal firebox has inlets extending therethrough that are fluidly coupled to the air conduit.

A high efficiency wood burning furnace assembly includes an internal firebox having a door positioned therein to access an interior of the internal firebox. An exhaust throat extends through an upper wall and a grate is mounted in the internal firebox and is spaced vertically above a lower wall. A primary diffuser is mounted within the internal firebox and is positioned adjacent the front wall and the grate. A primary air supply is in fluid communication with the primary diffuser to supply air to the primary diffuser such that the air is released along an upper surface of the grate. An air conduit is mounted in the internal firebox and extends upwardly from the primary diffuser. The air conduit releases air vertically above the grate and the primary diffuser. A front wall of the internal firebox has inlets extending therethrough that are fluidly coupled to the air conduit.

An appliance comprising a firebox, a first air duct and a room air chimney. During operation of the appliance heated room air adjacent to a viewing pane or the screen and heated room air from the first air duct is received within the chimney. The heated air within the chimney rises toward an open upper end causing the chimney to draw additional room air from adjacent to the viewing pane or screen.

A combustion device includes a body defining a firebox, a viewing window in front of the firebox, an upper plate adjacent to a top side of the firebox, a first air passage extending from an end adjacent to a rear end of the body to a second end adjacent to a front end of the body, and a second air passage adjacent to a back side of the firebox. The second air passage has a communication opening at an end communicated with the firebox. The communication opening is at a height higher than a height of a bottom side of the firebox and lower than a height of the top side of the firebox. A burner is disposed within and adjacent to the bottom side of the firebox.

A fireplace system can comprise a firebox and a heat exchanger. The heat exchanger may be in fluid communication with ambient air and may comprise an inlet configured to draw air into the front of the heat exchanger. Operation of a fireplace system comprising a heat exchanger may produce airflow through the heat exchanger by natural convection. The airflow through the heat exchanger may reduce heat transmission from the firebox and the fireplace system.

A fireplace system can comprise a firebox and a heat exchanger. The heat exchanger may be in fluid communication with ambient air and may comprise an inlet configured to draw air into the front of the heat exchanger. Operation of a fireplace system comprising a heat exchanger may produce airflow through the heat exchanger by natural convection. The airflow through the heat exchanger may reduce heat transmission from the firebox and the fireplace system.

An appliance comprising a firebox, a first air duct and a room air chimney. During operation of the appliance heated room air adjacent to a viewing pane or the screen and heated room air from the first air duct is received within the chimney. The heated air within the chimney rises toward an open upper end causing the chimney to draw additional room air from adjacent to the viewing pane or screen.