Rapid Exploitation of Building Energy Design Through Compact TRNSYS Modeling

This paper presents the development of a new modeling support tool able to simulate, with a reasonable workload, 36 integrated building-plant systems with different scales and resolutions, in order to support architects and HVAC designers/engineers in their modeling efforts, providing them with an extremely flexible, guided and accurate tool which does not require specific expertise during its use. The starting point is represented by a detailed model created with the calculation engine TRNSYS, which allows for dynamic and integrated simulation of the building envelope, heating plant subsystems, and plant components related to the production of the domestic hot water. The paper explores the 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, still maintaining a very high degree of accuracy with respect to the computational results and real energy consumptions. The protocols are applied to different case studies, first for the detailed modeling and progressively enhancing the level of simplification. The results show that the accuracy of the most simplified model in terms of heating loads and efficiencies is always below 16% with respect to the most detailed model, but with up to 90% modeling and simulation workload reductions. In this way the dynamic simulations could become an everyday working tool, with a greater amount of outputs in order to avoid plant oversizing and design errors.