WILL EQUATION-BASED BUILDING SIMULATION MAKE IT? -- EXPERIENCES FROM THE INTRODUCTION OF IDA INDOOR CLIMATE AND ENERGY

In building simulation, as in several other domains, traditional monolithic simulation codes are still in dominance over simulators based on symbolic equa- tions in a general modeling language. Introduced in 1998, IDA Indoor Climate and Energy has become the first widely spread thermal building performance simulator based on the new technology. Developing a full-fledged dynamic whole-building simulation pro- gram is a formidable endeavor in any setting and since the first beta version in 1997 a number of les- sons have been learned. The paper shares some of these experiences concerning general program struc- ture and GUI design as well as issues specifically linked to equation-based modeling using a variable timestep differential-algebraic (DAE) solver.