Enhancing outdoor comfort through tensile membrane structures and pavement Surfaces: A case study report in Évora, Portugal

Abstract

The Universal Thermal Climate Index (UTCI), developed in 2009 through collaboration among experts in human thermophysiology, aims to evaluate the relationship between the outdoor environment and human well-being. The case study focused on assessing the impact of shadowing and thermal masses on occupant outdoor thermal comfort as measured by the UTCI. The study specifically examined the effects of various designs of tensile membrane structures (TMS) on a U-shaped patio enclosed by nine maritime containers arranged in three groups of three levels in Évora, Portugal. The model tested fourteen TMS with varying slopes, overlap angles, lengths, repetitions, and four different pavements with distinct thermal mass layouts. The methodology employed dynamic simulation software, the energy engine EnergyPlus 2022, to assess the monthly variation of UTCI temperatures, comparing them to the scenario of an uncovered patio for each pavement configuration. The best-performing patio follows a TMS with a slope of 38.2°, an overlap of 74.4°, a length of 3.88 m, and five repetitions, accompanied by a full-concrete pavement. During winter (>9°C), the best-performing TMS underperforms against the uncovered patio by adding 1.1 °C but during summer (>26 °C), outperforms by reducing user discomfort by 9.4 °C. The global temperature deviation with the best-performing TMS sets at 3.3 °C, where the uncovered patio at 11.8 °C, is out of the comfort gap (9 °C to 26 °C) by 8.3 °C, benefiting user comfort across the year. The study highlights the potential of optimizing outdoor spaces based on UTCI measurements to create comfortable and user-friendly environments.