The buildings sector has a significant impact on the environment, considering that in addition industry and transport among the largest consumers of energy. Preservation of the external appearance of building façades and high standards in terms of thermal comfort have led to the development of systems in which many indoor units can be connected to a single outdoor unit. Such systems are widely known as variable refrigerant volume/variable refrigerant flow systems. However, the constant need to increase energy efficiency has given rise to new technology, named variable refrigerant temperature. Here, the first and Second law approach of an air-source heat pump with modern control strategies which worked in the moderate continental climate was performed. To fully understand the processes, the total exergy destruction for every main component split unavoidable and avoidable part. The results show the biggest negative impact on exergy efficiency of observed system has internal ireversibilities in the speed control compressor with 17.4%. Destroyed work in other main components generated cumulative negative impact of 26.7% and the exergy losses reduced exergy efficiency by 33.5%. If the available modern technologies are applied, the 27% of destroyed useful work in compressor can be avoided, but the bigger part (73%) is unavoidable.