Paper Conference

Proceedings of Building Simulation 2009: 11th Conference of IBPSA



Olena Kalyanova, Per Heiselberg, Clemens Felsmann, Harris Poirazis, Paul Strachan, Aad Wijsman

Abstract: 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. of buildings with double facades. However, the results of these investigations show considerable variation: the calculated energy efficiency of DSFs varies between significant annual energy savings and major annual increases in energy use for cooling. The design, dimensioning and application of DSFs is particularly important, because poor design can lead to increased energy use (mainly for cooling) and inferior indoor climate, compared to a building with conventional façade. Although there have been many validation studies that have helped to increase confidence in the use of existing design tools for the performance assessment of conventional buildings, their accuracy for prediction of double façade performance has not been tested to the same extent. To be able to design DSF buildings, engineers and architects must have confidence in simulation models for evaluating their thermal and energy performance. To investigate the applicability of various thermal building simulation tools for modelling DSFs, an empirical validation of building simulation software was conducted in the frame of IEA SHC Task 34 /ECBCS Annex 43 “Testing and Validation of Building Energy Simulation Tools”. The main outcomes of this work are presented in this paper. Table 1 Organisations and programs participating in empirical validation exercises Organization Program However, some models showed reasonable agreement with the experimental results for the thermal buffer mode.
Pages: 1107 - 1114