An aluminum alloy brazing sheet exhibits excellent brazability by effectively weakening an oxide film formed on the surface of a filler metal. The aluminum alloy brazing sheet includes a core material and a filler metal, and is used to braze aluminum in an inert gas atmosphere or in vacuum, the core material including aluminum or an aluminum alloy, the filler metal including 6 to 13 mass % of Si, with the balance being Al and unavoidable impurities, and one side or each side of the core material being clad with the filler metal, wherein the core material is clad with the filler metal in a state in which a sheet material is interposed between the core material and the filler metal, the sheet material including one element, or two or more elements, among 0.05 mass % or more of Li, 0.05 mass % or more of Be, 0.05 mass % or more of Ba, and 0.05 mass % or more of Ca, with the balance being Al and unavoidable impurities.

A retrofittable towel warmer for use with a hot tub preferably comprises a flexible conduit portion which is attachable to one of the jets of the hot tub together with a rigid thermally conductive portion which is detachably mountable on an exterior mast support. There is also preferably provided an exterior housing surrounding the thermally conductive portion designed to provide maximum thermal contact with the cloth material to be heated. The entire unit may be immersed in the hot tub or pool water when not in use. In an alternate embodiment a container having a thermally absorptive medium is provided in a structure which is easily mounted on the mast. In an alternate embodiment a container having a thermally absorptive medium is provided in a structure which is easily mounted on a supporting mast.

An aluminum alloy brazing sheet exhibits excellent brazability by effectively weakening an oxide film formed on the surface of a filler metal. The aluminum alloy brazing sheet includes a core material and a filler metal, and is used to braze aluminum in an inert gas atmosphere or in vacuum, the core material including aluminum or an aluminum alloy, the filler metal including 6 to 13 mass % of Si, with the balance being Al and unavoidable impurities, and one side or each side of the core material being clad with the filler metal, wherein the core material is clad with the filler metal in a state in which a sheet material is interposed between the core material and the filler metal, the sheet material including one element, or two or more elements, among 0.05 mass % or more of Li, 0.05 mass % or more of Be, 0.05 mass % or more of Ba, and 0.05 mass % or more of Ca, with the balance being Al and unavoidable impurities.

Heat exchanger, comprising a series of interconnected modules, each module comprising at least part of a water duct and part of a flue duct, wherein at least the parts of the water ducts of successive modules are interconnected, forming at least one continuous water duct through and/or along a number of said modules, wherein water duct parts of two adjacent modules are interconnected by a connector inserted into an opening in at least one of the modules forming a sealing connection.

Heat exchanger, comprising a series of interconnected modules, each module comprising at least part of a water duct and part of a flue duct, wherein at least the parts of the water ducts of successive modules are interconnected, forming at least one continuous water duct through and/or along a number of said modules, wherein water duct parts of two adjacent modules are interconnected by a connector inserted into an opening in at least one of the modules forming a sealing connection.

A room perimeter heating/cooling radiator with a non symmetrical elliptical transverse cross section, that utilizes low to medium temperature heat transfer fluid (generally water or water/glycol) in a new design with an enhanced primary only heat transfer surface having an internal spiral or helix to circulate the water around the inside of the primary surface to enhance the heat transfer, and an internal conduit that provides both freeze damage protection and the ability to cross connect multiple identical radiators for increased efficiency. The primary intended location is within inches of the building windows.

A retrofittable towel warmer for use with a hot tub preferably comprises a flexible conduit portion which is attachable to one of the jets of the hot tub together with a rigid thermally conductive portion which is detachably mountable on an exterior mast support. There is also preferably provided an exterior housing surrounding the thermally conductive portion designed to provide maximum thermal contact with the cloth material to be heated. The entire unit may be immersed in the hot tub or pool water when not in use. In an alternate embodiment a container having a thermally absorptive medium is provided in a structure which is easily mounted on the mast. In an alternate embodiment a container having a thermally absorptive medium is provided in a structure which is easily mounted on a supporting mast.