Solar heating system multiple layer liq. conveying tube - has semiconductive tube with black outer layer or coating

摘要

A tube for conveying hot water is designed for a solar heating system, and consists of an electrical semiconductor material with a heat resistant layer. The tube may have the semiconductor material tube enclosed by a wound on layer of black material. The inner tube may be of plastics, with a semiconductor coasting. In an alternative design, where the tube may also be electrically heated, e.g. for frost protection, electric resistance wires may be included between the inner and outer layers, or between the layers of a multiple layer tube. The wires may be helically wound around the inner tube, or along it, in parallel paths. Black foil may be wound around the outside.