A multi-stage approach for building and HVAC model validation and its application to a Swiss office building

In the Swiss research project OptiControl (www.opticontrol.ethz.ch), new predictive building control strategies are developed and applied to a fully occupied, well instrumented demonstrator building. Here we report on the development and validation of the EnergyPlus building energy performance simulation model used in the project.  Validation was done in three stages: (i) plausibility testing, (ii) tuning of room temperature dynamics based on HVAC excitation experiments, (iii) comparison of longer-term net energy and room temperature statistics in different operation modes.  The mean and variability of spatially averaged indoor temperatures were generally well reproduced.  Simulated total heating and cooling net energy usage showed however in many cases deviations > 50%.  They were traced plausibly (but not conclusively) to specific modeling and input assumptions.  Validation results depended strongly on incorporation of controller feedback in the simulations.  The used validation strategy helped to improve the model and advanced the understanding of the building.