TA-23-C003 – Investigation into the Pertinence of Using Child-Specific Radiation Data for Thermal Comfort Calculations

View factors are dependent on the shape and size of occupants, yet standards rely on the same values for all occupants regardless of their anthropometric measurements. Past research has quantified the impact on projected area factors (f_p) of height and weight differences amongst a specific adult population and between adult populations of different regions. Yet thus far, children’s view factors have neither been calculated nor compared to adults’. To address this gap, we generated a computational manikin representative of a 5-year-old American child of average proportions using data from the US National Health and Nutrition Examination Survey and a human shape generator from the University of Michigan Transportation Research Institute. We calculated view factors between this child manikin and its surroundings numerically using the hemicube method and compared them to those of an adult manikin representing the average participant in Horikoshi et al.’s 1990 experiment. Comparing the numerical results for the adult manikin to those of Horikoshi’s experiment allowed us to verify our computational method. A small room with radiant floor heating was used as a test case to propagate the effect of the view factor differences between adult and child to the calculated MRT. We found that differences between the view factors of the five-year-old child manikin and the adult are sufficient to change the MRT by 0.5°C in the test case studied, indicating using adult view factors to calculate the MRT is inadequate for children. Further work is needed to document view factors of different child age groups and to investigate further implications in the design of spaces occupied by children.