This document specifies the energy performance calculation of water-based distribution systems for space heating, space cooling and domestic hot water (DHW).

This document is applicable to the heat flux from the distributed water to the space and the auxiliary energy of the related pumps.

The heat flux and the auxiliary energy for pumps can be calculated for any time interval (hour, month and year). The input and output data are mean values of the time interval.

Instead of calculating the energy performance of water-based distribution systems, it is also possible to use measurements as long as they follow the time intervals of the whole performance calculation or can be divided into those time intervals.