Trnsys integrated modeling support tool for a fast building-plant system design

The present thesis stems from the benefits of the application of energy analysis in any stage of building-plant system design. The research highlights the barriers that prevent this integration and finally proposes the development of a dynamic modeling support tool able to simulate, with a reasonable workload, a very large number of integrated building-plant systems with different scales and resolutions, in order to have a guided design support for architects and HVAC designers/engineers, reducing their modeling effort and errors. The starting point is represented by a flexible and detailed model created with the calculation engine TRNSYS, which allow for the dynamic and integrated simulation of the building envelope, all the heating plant subsystems, and all the plant components related to the production of domestic hot water. The research explores then strategies and simplifications that can considerably reduce the number of necessary inputs for the simulations, thus minimizing the modeling, implementation and simulation runtime of the model, while still maintaining an acceptable degree of accuracy with respect to the computational results and real energy consumptions. Those results are achieved by defining a methodology, which consists in developing a sizing protocol and a simplification protocol and applying them to real life, complex case studies, first modeling detailed models and progressively enhancing the level of simplification. At each progressive simplification step, the comparison with the detailed model results is given in terms of building energy needs, power curves, efficiencies, modeling and simulation workloads. In particular results show that the accuracy of the most simplified model is always below the 16% with respect to the most detailed model, with a 90% modeling and simulation workload reductions, able to make the tool easy to be adopted at every stage of building-plant system design.