Abstract: In order to improve the transfer of heat within a heat exchanger, one or more tubes (11) for a heat transporting medium are embedded by casting into a block (12a) of an aluminum alloy or some other metal having a high heat-conducting capacity. The block is at its outward faces provided with surface-enlarging flanges (15), and is enclosed in a casing (13) which defines a passage for a second heat-transporting medium flowing around the block (12a). A block can be prismatic or annular, and a number of blocks can be fitted within the same casing. In one embodiment, electric resistance elements are provided within the embedded tubes as a first heat-transporting medium in order to obtain an electrically heated heat exchanger, with the second heat-transporting medium being for example oil.

Abstract: An electric space heater includes an elongated horizontally-disposed hollow metal pipe having opposite open ends and a bottom portion with a longitudinally extending opening; support legs for supporting the pipe at its opposite ends above a surface; an electric heating element mounted substantially centrally within the pipe at the bottom portion; and an electric cord for supplying electricity to the electric heating element to control the latter to heat the ambient atmosphere by radiation from the pipe and by forced air convection through the opposite open ends.