This document specifies design criteria for heating and cooling systems in buildings using electrically driven heat pumps for heating and cooling alone or in combination with other heat generators. The heat pump systems considered in this document (source system/sink system) are listed in Table 1. For cooling purposes, energy source and energy sink can be reversed. This document also applies to other energy sources such as wastewater, massive absorbers, ice storage systems, as well as heat pump systems using more than one energy source. This document takes into account the heating requirements of attached systems (e.g. domestic hot water) in the design of the heat supply but does not cover the design of these systems. This document covers the aspects dealing with the heat pump, the interface with the heat distribution system and heat emission system, the control of the whole system and the aspects dealing with energy source of the system. Design criteria for reversible heat pump sys
