On the scalability of equation-based building and district simulation models

Equation-based models are often discussed as the future of building simulation. In fact, the first papers about this date back to the early eighties. In recent years, the development and universal adoption of Modelica has revolutionized the use of equation-based modelling for a broad range of engineering applications. Consequently, several research groups have focused on the mission of applying Modelica to building simulation problems. However, in building simulation as in many other engineering domains, scalability – the ability to work on realistically large models – has proven to be insufficient. Despite the existence of comprehensive model libraries, classical Modelica tools do not seem to deliver results that are useful for widespread industrial adoption. The paper presents a range of representative Modelica benchmark models that have been simulated in IDA ICE as well as in other Modelica environments. Radical differences in scalability are observed.