A synoptic analysis of the effect of radiance on human perceived temperature

Abstract

Accurate modeling of local microclimate parameters such as Mean Radiant Temperature ($T_{\mathrm{mrt}}$) is essential for the assessment of indices used to quantify the human experience of the environment. This study presents a high-resolution multiphysics simulation approach to evaluate $T_{\mathrm{mrt}}$ used for the assessment of the Physiological Equivalent Temperature (PET) within a densely built urban area. The simulation incorporates geometry and material properties of roads, buildings and vegetation, as well as incoming airflow and short and longwave radiance. Airborne and terrestrial infrared thermography was used to capture spatially and temporally resolved measures of surface temperature. Simulation results highlight the influence of radiation on PET, particularly in confined urban spaces with limited ventilation, demonstrating the effect of vegetation, $T_{\mathrm{mrt}}$, and airflow. Point by point correspondence of simulation versus the measurement was carried out using best practice guidelines for the application of Longwave Infrared imaging for full field assessment of surface temperature. Results are presented for simulation carried out in an area of downtown Manhattan, where surface temperatures are used for the assessment of PET at 1.5 m above ground level at ¾ million locations.