Energy performance assessment of single storey multiple-skin facades

Multiple-skin facades were studied by means of experiments and numerical simulations. Experimental work was done on naturally and mechanically ventilated single storey multiple skin facades. Field experiments showed that good design and excellent workmanship are of crucial importance to obtain the desired performance. The measurements enables an insight into the complex nature of the airflow in naturally ventilated cavities. Measurements on a controlled experimental set-up provided data to develop and validate a numerical model. This model was then implemented in an energy simulation tool. The calculation results for a traditional facade with exterior shading devices, a naturally ventilated double-skin facade and two mechanically ventilated multiple-skin facades were compared. The results show that using multiple-skin facades improves some components of the overall building's energy use, and that evaluating the energy efficiency of such facades can not be performed by solely analysing the transmission losses and gains ; it is imperative to take into account the enthalpy change of the cavity air and to perform a whole building energy analysis.