Thermal-physical behaviour and energy performance of air-supported membranes for sports halls: a comparison among traditional and advanced building envelopes

In the last decade textile architecture has become increasingly popular: fabrics and foils are more and more used as skins for permanent and enclosed buildings. The thermal-physical behavior of air-supported membrane structures, characterized by low thermal inertia and poor insulation, is definitely different from the traditional architectures, although required comfort levels are often similar. While the thermal behavior of the wider spread ETFE foil cushion system is still investigated, a quantitative assessment of the double-layered fabric skin energy performance is still lacking. This paper studies the latter membrane system, focusing on the evolution of air-supported envelopes for sports halls, from single layer to double layer membranes, either based on pneumatic cushions or on continuous air gaps. By performing measurements on running sports halls and dynamic simulations, the winter energy performance, the comfort conditions and the internal surfaces condensation risk of a typical sport hall in Northern Italy are evaluated. An insight is given into the envelopes dynamic behavior and energy balance. Double layers envelopes allow saving from 11% to 18% of the heating energy compared to single layer. Moreover, further energy saving strategies are proposed and quantified, considering low-emissivity coatings, reduction of the cracks areas, modifying indoor air set points.