Presents the development of two prototypes of a 10 kW periodically operating absorption heating unit for space heating applications, which can deliver the required heat by monovalent operation in the heat pump mode and at evaporation temperatures below 0 degC in the boiler mode. Describes the working principle and describes and discusses experimental results. In addition deals with the analysis of manufacturing and operational costs of the unit.

KEYWORDS: Heat pumps, absorption heat pumps, Germany, space heating, domestic, prototypes, hot water supply, experiment, costs, cost in use.