2025-09-09 –, Audi-Midi
Today's process for designing, specifying, installing and testing building HVAC control is not digitalized, leading to expensive manual workflows and missed operational performance. To digitalize the design-build-operate process for building HVAC control, the authors developed a process, associated tools and initiated the voluntary ASHRAE Standard 231P. This paper describes this process and tools, which are both based on Modelica. Standardization through a proposed voluntary ASHRAE Standard and the existing Modelica Language Specification provides a robust technology foundation for industry investment. It is based on declarative specification of the control logic, and allows reuse of existing technologies for open-loop and closed-loop control testing through coupling with an HVAC system or a whole building energy model. It supports control testing using MIL, SIL and HIL, and export of digital twins for operational support. The process and ASHRAE Standard 231P have been designed to accommodate existing Building Automation Systems product lines, while also enabling direct code generation such as by using FMI or eFMI. Control deployment can be digital or manual and conformance to the digital specification can be tested formally and programmatically at each step of the control delivery.
Michael Wetter is a Senior Scientist at the Lawrence Berkeley National Laboratory.
His research includes integrating building performance simulation tools into the research process, as well as their use for design and operation. He is leading the development of the Modelica Buildings Library, of OpenBuildingControl, and of Platform Based Design for energy systems.
He was the co-operating agent of IBPSA Project 1 and of IEA EBC Annex 60 and he now leads the IBPSA Modelica Working Group, three multi-national projects that led to the Modelica IBPSA Library that is now used as the core of the Buildings, the AixLib, the IDEAS, and the BuildingSystems libraries.
He is a recipient of the bi-annual Outstanding Young Contributor Award of IBPSA, and of the bi-annual Distinguished Achievements in Building Simulation Award of IBPSA-USA. He is the Chair of the College of Fellows of IBPSA, an IBPSA Fellow, and a member of the Board of the Modelica North America Users’ Group. He was Treasurer of IBPSA and President of IBPSA-USA.
