Abstract: A range for sealed combustion of a gaseous fuel has a hob assembly and an oven. The hob assembly comprises a glass ceramic cooking surface sealed to a support box and one or more burners. The hob assembly and oven are connected to a fresh air intake/exhaust manifold, such that there is no air exchange between the range and the room in which it is located. Narrow heat transfer passageways are defined between the cooking surface and an internal surface around each burner.

Abstract: There is provided a range for sealed combustion of a gaseous fuel comprising a hob assembly and an oven. The hob assembly comprises a glass ceramic cooking surface sealed to a support box and one or more burners. The hob assembly and oven are connected to a fresh air intake/exhaust manifold, such that there is no air exchange between the range and the room in which it is located.

Abstract: A sealed combustion, low profile gas-fired baseboard heater has a heat exchanger which is U-shaped, and which has upper and lower horizontal sections. Appropriate inlets are provided for air and combustion gas, and a gas valve. The air inlet may be coaxial with an exhaust for combustion gases. The heater may include a combustion blower, in which case the heat exchanger can include fins and other features to improve heat transfer. A natural draft version includes a larger bore tubular heat exchanger. Ignition can be by way of a pilot. Alternatively, a hot surface igniter, with safety lockout-timing device, can be used.

Abstract: Improved furnaces are described in which secondary and tertiary heat exchanges are incorporated into new and existing hot-air furnace systems for controlled cooling of hot combustion products by co-current and countercurrent heat exchanges. Hot combustion products are cooled to a temperature at which latent heat of water vapor contained in combustion gases are substantially recovered.In one embodiment of our invention, a secondary heat exchanger comprises inter alia a closed hollow annular drum concentric with and spaced from a cylindrical combustion chamber, said annular drum having an upper annulus preferably filled with randomly packed refractory material.A second embodiment of our invention comprises a closed double-annuli drum heat exchanger concentric with and spaced from a cylindrical combustion chamber.Finned tube or thermosiphon heat exchangers can be arranged sequentially with the primary heat exchanger combustion chamber to function as a secondary heat exchanger or as a tertiary heat exchanger.