Abstract: A method of primarily testing and performance controlling heat pumps, refrigerating installations or corresponding systems, at which system thermal energy from at least one heat source (K) is supplied to an energy-carrying medium (1), a refrigerant, which circulates in the system and is advanced therein by at least one, preferably electrically driven compressor (2) and is caused to pass through at least one condenser (VVX) where thermal energy is emitted and exchanged to a thermal energy carrying medium, a thermal sink, where the control comprises the determining of real performance, such as thermal output (Q.sub.1) and so-called coefficient of performance (COP) against the background of measurements. The method is especially characterized in that performance, such as thermal output (Q.sub.1,f) or refrigerating output (Q.sub.1,f) and coefficient of thermal performance (COP.sub.f) or coefficient of refrigerating performance (.epsilon..sub.