Calibration of Hygrothermal Simulations by the Help of a Generic Optimization Tool

Hygrothermal simulation represents an established method for the performance evaluation of building constructions. Some validation cases are known where the validity of these models was approved in form of a comparison between measured and simulated quantities under controlled boundary conditions. A further step is commonly not explained but also included, the calibration of uncertainly known model settings, e.g. surface exchange coefficients or measured material properties with a relevant uncertainty range. This paper summarizes a calibration procedure, which was carried out for the data analysis of a hygrothermal test stand with two- and three-dimensional junctions, including brickwork and joist ends. The calibration procedure is based on the definition of quantitative criteria (target values) that describe the accordance between measured and simulated data series. Starting with the thermal two-dimensional simulation model, uncertain parameters are defined with their start values, ranges and steps of variation. This is used as an input for the identification of the best-fitting parameter combination via generic optimization algorithm. The final calibrated simulation model shows a remarkably better accordance to the measurement results. The procedure is systematic and reproducible.