ISO 13612 is applicable to heat pumps for space heating and cooling, heat pump water heaters (HPWH), and heat pumps with combined space heating and cooling and domestic hot water production, in alternate or simultaneous operation, where the same heat pump is used for space heating and cooling and domestic hot water heating.

ISO 13612-1:2014 establishes the required inputs, calculation methods, and required outputs for heat generation for space heating and domestic hot water production and control of the following heat pump systems: electrically driven vapour compression cycle (VCC) heat pumps; combustion engine-driven VCC heat pumps; thermally-driven vapour absorption cycle (VAC) heat pumps.

ISO 13612-1:2014 specifies the design and dimensioning criteria for the heating and cooling systems in buildings using heat pumps alone or in combination with other heat generators. These include the following: water?water; brine?water; refrigerant?water (direct expansion systems); air?air; air?water; combined; systems driven by electricity or gas.

ISO 13612-1:2014 takes into account the heating requirements of attached systems (e.g. domestic hot water, process heat) in the design of heat supply, but does not cover the design of these systems. It covers only the aspects dealing with the heat pump, the interface with the heat distribution and emission system (e.g. buffering system), the control of the whole system, and the aspects dealing with the energy source of the system.