Modelling of heat generators: technical standards vs detailed dynamic simulation tools

In the last years, international technical standards have introduced several procedures for modelling the heat generation sub-system, both providing new calculation methods and updating the old ones. A still open issue concerns the modelling of these subsystems, by adapting the standard procedure – usually founded on simplified assumptions – to the structure of a detailed dynamic simulation tool. Another major issue is the lack of data from the manufacturers related to part load operation of generators. In this paper, the main procedures introduced by the international technical standards issued under the Mandate M/480 EN of 2010 on the heat generation sub-systems are presented, with a focus on combustion systems, chillers, and heat pumps. Simplifications and assumptions are analysed, by pointing out the limits related to the simplified modelling based on empirical correlations and tabulated values. The heat generation standardised models are compared with the ones used in detailed simulation tools, such as EnergyPlus. The main differences in the input data and in the model options are presented, and advices for the completion of the information commonly found in technical data sheets are provided. The paper is aimed both at promoting an effective application of the standards in the building design field and at contributing to the standardisation activity for the achievement of more accurate calculation models.