Abstract: A geothermal heat exchanger, a geothermal heat arrangement and to a method in connection with a geothermal heat arrangement. The geothermal heat exchanger includes a piping arrangement having a rise pipe and a drain pipe, and a first pump arranged to the piping arrangement. The rise pipe and drain pipe are arranged in fluid communication with each other for circulating the primary working fluid. The rise pipe is provided with a first thermal insulation surrounding the rise pipe along at least part of the length of the rise pipe and the first pump is arranged to circulate the primary working fluid in a direction towards a lower end of the rise pump.

Abstract: A method and arrangement for conditioning a building space of a building includes extracting heat energy from the building space to heat pump working fluid with a primary heat exchange connection of a heat pump and releasing heat energy from the heat pump working fluid with a secondary heat exchange connection of the heat pump to geothermal working fluid of a geothermal heat exchanger. The method further includes releasing heat energy from the geothermal working fluid to ground at lower part of the ground hole having depth at least 300 meters, producing solar energy with a solar energy apparatus provided to the building, and supplying the solar energy to the heat pump or to the geothermal heat exchanger.

Abstract: A system, an arrangement and method for heating and cooling of several building spaces-or buildings includes two or more building spaces or buildings, and a secondary thermal network including a supply line and a return line. The arrangement further comprises two or more building connections arranged parallel to each other and between the supply line and provided in connection with the two or more building spaces or buildings, a ground hole and a geothermal heat exchanger provided to the ground hole and arranged in connection with the secondary thermal network.

Abstract: A geothermal heat exchanger, a geothermal heat arrangement and to a method in connection with a geothermal heat arrangement. The geothermal heat exchanger includes a piping arrangement having a rise pipe and a drain pipe, and a first pump arranged to the piping arrangement. The rise pipe and drain pipe are arranged in fluid communication with each other for circulating the primary working fluid. The rise pipe is provided with a first thermal insulation surrounding the rise pipe along at least part of the length of the rise pipe and the first pump is arranged to circulate the primary working fluid in a direction towards a lower end of the rise pump.

Abstract: A heating apparatus for preparing an optical fiber from a preferably vertical fiber preform in a draw furnace, in which draw furnace the fiber preform is heated with the heating apparatus in the heating zone of the draw furnace in such a way that a molten, downwards tapering zone is formed in the preform, from which a thin fiber is produced by means of gravity and/or drawing the fiber downwards, which heating apparatus comprises at least a preferably tubular heating element, placed around the fiber preform in the draw furnace, for heating the fiber preform, and a heating means placed around the heating element in the draw furnace, for heating the heating element, as well as an insulator element around the heating element. The heating element and the insulator element are surrounded at least partly by a radiation shielding to reflect thermal radiation from the heating element to the insulator element back to the heating element.