An empirical validation of building simulation software for modelling of double-skin facade (DSF)

Double-skin facade (DSF) buildings are being built as an attractive, innovative and energy efficient solution. Nowadays, several design tools are used for assessment of thermal and energy performance of DSF buildings. Existing design tools are well-suited for performance assessment of conventional buildings, but their accuracy might be limited in cases with DSFs because of the complexity of the heat and mass transfer processes within the DSF.  To address this problem, an empirical validation of building models with DSF, performed with various building simulation tools (ESP-r, IDA ICE 3.0, VA114, TRNSYS-TUD and BSim) was carried out in the framework of IEA SHC Task 34 /ECBCS Annex 43 “Testing and Validation of Building Energy Simulation Tools”. The experimental data for the validation was gathered in a full-scale outdoor test facility. The empirical data sets comprise the key-functioning modes of DSF: 1. Thermal buffer mode (closed DSF cavity) and 2. External air curtain mode (naturally ventilated DSF cavity with the top and bottom openings open to outdoors).  By carrying out the empirical tests, it was concluded that all models experience difficulties in predictions during the peak solar loads. None of the models was consistent enough when comparing simulation results with experimental data for the ventilated cavity. However, some models showed reasonable agreement with the experimental results for the thermal buffer mode.