Abstract: A high-pressure mercury vapor discharge lamp whose envelope two tungsten electrodes disposed therein of tungsten and a filling containing a rare gas, a quantity of mercury larger than 0.2 mg/mm.sup.3 at a mercury a pour pressure of more than 200 bar and at least one of the halogens chlorine, bromine or iodine in a quantity between 10.sup.-6 and 10.sup.-4 .mu.mol/mm.sup.3. The wall load in operation is higher than 1 W/mm.sup.2.

Abstract: In a gas discharge lamp having a discharge vessel containing an ionizable gas filling and consisting of a translucent material, which is surrounded at a certain distance by a translucent outer bulb, the discharge vessel has a thermally insulating translucent envelope of a microporous aerogel.

Abstract: An air conditioner comprises an air-to-air heat exchanger; a fresh air supply duct, a fresh air by-pass duct, a used air exhaust duct, and a used air by-pass duct, the fresh air supply duct and the used air exhaust duct being respectively connected to the air-to-air heat exchanger, the fresh air supply duct having a part in common with the used air by-pass duct, and the used air exhaust duct having a part in common with the fresh air by-pass duct. Included are a condenser provided in the common part of the fresh air supply duct, and an evaporator provided in the common part of the used air exhaust duct, the condenser and the evaporator being parts of a heat pump. A blower is provided in the common part of the fresh air supply duct and is connected to the used air by-pass duct, and a separate blower is provided in the common part of the used air exhaust duct and is connected to the fresh air by-pass duct.

Abstract: A solar collector for heating a gaseous heat transport medium comprises an open-top housing provided with a transparent cover layer formed of a plurality of adjacently arranged, substantially mutually contacting, sealed and evacuated transparent cover tubes. The inner surface of each cover tube is provided with a selective absorption layer over the half facing the interior of the housing. The surface of the housing bottom facing the cover tubes has a vaulted profile corresponding to the shape of the cover tubes. An inlet and an outlet are respectively provided in the opposite sidewalls of the housing for flow of the gaseous heat transport medium transversely of the cover tubes in direct thermal contact herewith.

Abstract: A wall element, comprising a solar collector which is arranged between two panes and which comprises a number of rotatable absorber plates. One side of the absorber plates is provided with a non-selective black coating and the other side is provided with a selective, heat-reflective layer. The absorber plates are accommodated in evacuated, transparent tubes.

Abstract: A solar collector comprising a heat exchanger having a corrugated surface and an entrance window composed of evacuated transparent tubes respectively in contact with the corrugations.

Abstract: A solar collector including at least one evacuated transparent cover tube provided with means for supplying hydrogen to and extracting hydrogen from the cover tube.

Abstract: A solar collector comprising an elongate solid cylindrical body extending lengthwise into an elongate cylindrical Dewar-type vessel in a manner to form annular-shaped supply and outlet ducts for a heat-transport medium, the sum of the cross-sectional areas of the supply and outlet ducts being less than one-quarter of the inner cross-sectional area of the vessel.

Abstract: A solar collector comprising an absorber and a heat-insulating transparent cover which consists of a number of sealed and evacuated glass tubes adjacently arranged in contact with each other, at least the lower half of the inner surface of each glass tube being provided with an infrared-reflecting layer.

Abstract: A thermal insulating glazing unit comprising a plurality of elongated evacuated sealed glass tubes arranged adjacent each other with their axes parallel, transverse to the light. The inner side of each of the glass tubes is covered by an infrared-reflecting coating.