Coupling Outdoor Heat Stress and Indoor Thermal Exposure in Dwellings: A Human Biometeorology Approach

The frequency and severity of heatwaves are on the rise globally, with several European cities in particular experiencing the most extreme phenomena in recent history. Over the past few years people have become increasingly aware regarding the implications of thermal stress on dwellings and living conditions. However, the links between outdoor weather drivers and indoor stressors are still under investigation. This study aims to shed light on those links, using the "living lab" of the Green Village at TU Delft as a reference site.

The MSc thesis-based research will incorporate field measurements and modelling output from both building physics and atmospheric science. Outdoor meteorological parameters such as air temperature, wind speed, humidity and solar fluxes will be used for the derivation of biometeorological indices from the Rayman modelling platform. The indices of interest are the Physiological Equivalent Temperature (PET) and the Universal Thermal Climate Index (UTCI), which will be used as boundary conditions for the study of the indoor environment. Indoor monitoring will include data for operative temperature, relative humidity and light irradiation. Furthermore, CO2 concentrations will be used as proxies for the study of occupant-driven ventilation. EnergyPlus simulations will quantify heat transfer, thermal storage and radiative exchanges in the building envelope. Results from the monitoring and the modelling campaigns will be complemented with the addition of human-centred research in the form of questionnaires and/or semi-structured interviews, in order to address thermal exposure from a biometeorological perspective.

All in all, this multi-layered research will attempt to quantify the impact of outdoor heat on indoor spaces while taking human perception into account. Enhanced understanding of these dynamics will facilitate future designs for houses in the face of climate change and extreme urban heat.

Keywords: Human biometeorology, Heat stress indices (PET, UTCI), Indoor thermal comfort, Urban climate adaptation, Indoor–outdoor thermal coupling