Extreme Soft Skins: Multi-layered ETFE for Challenging Environments

ETFE has been rapidly expanding its presence in the building industry, finding its application on all parts of the envelope, especially skylights due to the superior light translucence (Monticelli, 2015). Recent technological developments of multi-layered ETFE systems coupled with advanced coatings have altered their performance and boosted their potential for applications across all latitudes. The paper presents the optical and thermal characterization of multi-layered ETFE foils performed at the TextilesHUB - the Interdepartmental Research Laboratory at Politecnico di Milano. Studies include ETFE with advanced silk-screen printed coatings and coating patterns for various real case projects in challenging environments, covering both cold and hot extremes. Special focus is placed on hygro-thermal analyses to inform the design of the frame to eliminate potential condensation caused by the hightemperature difference between both sides and very low thickness at the edge of the ETFE cushions, where all layers converge into framing gasket. Moreover, the paper presents an optimization process for improving performance of ETFE layer compositions to mitigate high environmental stresses, provide optimal indoor comfort and reduce energy demand. Finally, we present achieved performance levels of different ETFE systems implemented in three projects in Sankt Petersburg, Milan and Manama and discuss possibilities for future improvements