Dynamic evaluation method for assessing households’ thermal sensation using parametric statistical analysis: A longitudinal field study in the South-eastern Mediterranean climate

Climate change is causing a wide range of impacts, including more frequent and brutal climate events, such as long-term heatwaves while compound effects of extreme weather events can dramatically disrupt indoor thermal conditions, causing increased mortality risks, especially for vulnerable populations with health conditions. Comfort standards do not give clear guidelines to determine the minimum or ideal range of continuous measurements, considering the climate change projections to determine neutral thermal comfort thresholds in 2030s, 2050s and 2080s. The aim of this study is to evaluate the predictive skills of existing long-term thermal comfort indices from the ASHRAE RP-884-II database and to propose new indices based on continuous, in-situ physical environmental measurements and subjective evaluations of social householders in naturally ventilated multi-family houses in the South-eastern Mediterranean basin. A meta-analysis of ASHRAE Global Thermal Comfort Database II showed that the acceptable temperatures extend across a wide range of conditions and vary depending on building type and climate. The results revealed that the Predicted Mean Vote (PMV) is the upper limit in ASHRAE standard-55’s 0.5 clothing value (clo) summer comfort zone stretches all the way to 27°C at 50% relative humidity with air speeds below 0.2 m/s. The results prove that the neutral mid-point of the summer comfort zone is at about 25.5°C regardless the neutral temperature was 28.5°C, and the upper limit of the comfort range in warm indoor air temperature conditions was 31.5°C in the South-eastern Mediterranean region. Our analysis reappraises the scope of applicability of the adaptive comfort standard, assess potential regional differences by considering the detrimental impact of climate change in adaptive thermal comfort responses, and propose mitigation strategies to adaptive comfort theory, the adaptive comfort model and standard and sustainable building design. Finally, we suggest that building operations should better regulate occupant’s psychological behaviour to adapt to warmer indoor conditions by implementing adaptive comfort algorithms to optimise occupants’ thermal comfort against the warming climate conditions. This could lead to improving energy performance of naturally ventilated buildings without sacrificing the occupant comfort.

The work presented has the outcome of the self-funded PhD doctoral research project by the co-author of the paper. Dt. Serife Gurkan provided substantial financial sources to complete this research project at the University of East London – School of Architecture, Computing and Engineering, Graduate School, London, United Kingdom and she provided financial support to the author at the time of writing this research paper.