Design methodology for combined production and distribution for domestic hot water and space heating

Abstract

As local heat demand is reducing due to an increased insulation rate, investing in sustainable heat production becomes less interesting. Nevertheless a substantial demand of heat remains in which the thermal energy needed for the generation of domestic hot water grows relatively in importance.In the last two years standards to size production and distribution systems were revised and methods based on tap patterns were elaborated. Nevertheless, some aspects were not covered yet, e.g. how to deal with decentralized storage and how to use these results and new insights in combined heating systems, taking into account that modifications in standards for both space heating and domestic hot water installations are reducing the oversizing. In this paper, first some critical points of attention due to this evolution are illustrated with a case example. Next it is shown how different rules of thumb often developed by different manufacturers deal with these aspects, but lacking however compatibility with existing standards and/or new insights. Finally, a methodology is proposed and illustrated how to size distribution and production systems for combined heating systems taking into account central and decentralized storage and different kind of end users. The method can be used to size heating systems in collective housing or in district heating networks.