A data-driven ray tracing simulation for mean radiant temperature and spatial variations in the indoor radiant field with experimental validation

A data-driven simulation technique is proposed for the calculation of the 3-dimensional radiant temperature distribution across a room with the aid of a ray tracing method. The proposed simulation accounts for interreflections of radiant heat fluxes from surfaces reflective in the longwave range within the indoor environment. The simulation provides results which include high-resolution spatial radiant field maps for indoor spaces as well as human body mapping for radiant heat fluxes received by different body segments, depending on the bodily position of a person in space. The simulation technique is validated with a physical experiment in a controlled climate chamber, where a heat-flux sensor array is used to measure the mean radiant temperature (MRT) by measuring the average plane radiant temperature in 6 directions at multiple points in space. The results for the experiment show excellent agreement between the simulated and measured results. The simulation allows one to resolve and visualize spatial variations of the radiant field, identify impact of radiant asymmetry and surface materials on the room's irradiation distribution as well as the variations on the human body in different positions and orientations. (c) 2021 Elsevier B.V. All rights reserved.