DIN V 18599-5:2016-10

DIN V 18599-5 determines the energy use of the heating system for the building according to its different subsystems. It is also possible to calculate the delivery of heat to the sectors covered by DIN V 18599-6 to DIN V 18599-8 and vice-versa.
It is also possible to calculate the energy balances of several building zones in which there are several units to be balanced.
Within the framework of DIN V 18599-5, the energy use of heating systems with their various subsystems (delivery, distribution, storage and generation) is described. For this purpose, both the thermal losses and the auxiliary energy of the individual subsystems are determined and, provided these occur within the heated zone, are made available for the ensuing calculations described in DIN V 18599-1 and DIN V 18599-2. Information is given on the possible influence of domestic hot water generation according to DIN V 18599-8. Recourse to the heating system by other systems (for example, ventilation of residential buildings as in DIN V 18599-6, or ventilation and air conditioning systems in non-residential buildings as in DIN V 18599-7), that can make demands on certain subsystems, can accordingly be taken into account and calculated. DIN V 18599-1 acts as the link between the parts.
It is assumed that heating systems are operated as intended and in keeping with accepted best practices. Special guidance, for example, with regard to the hydraulic balance of the hot water heating system, is given in VDMA 24199.
The required energy use can be calculated using either the methods described in clause 6, or by other or deviating calculation methods (for example, DIN V 4701-10, DIN V 4701-12 and PAS 1027), provided these alternative methods deliver equivalent results under comparable boundary conditions (see DIN V 18599-10). The assumptions and boundary conditions on which these calculations are based shall be recorded systematically and shall apply to the annual heating need Q_h,b.
The energy need values calculated using this procedure cannot be used to size individual components. Systems not covered by this document shall be assessed by analogy with DIN V 18599-5 and using other, physically-based algorithms.
DIN V 18599-5 has been approved by NA 005-12-01 GA "Gemeinschaftsarbeitsausschuss NABau/FNL/NHRS: Energetische Bewertung von Gebäuden" ("Joint Working Committee NABau/FNL/NHRS: Energy efficiency of buildings") and published as a prestandard.