An energy budget model for estimating the thermal comfort of children

Many children growing up in cities are spending less time outdoors to escape the heat. This is contributing to childhood obesity and the prospect of a range of diseases in adulthood. When landscape architects and urban designers use a human thermal comfort model to test their designs for children's comfort, they would have to use a model essentially designed to simulate healthy adults. Yet there are many differences between the body of a child and an adult. The aim of this paper was to modify the thermal comfort model COMFA into a children's energy budget model through the consideration of the heat exchange of a child. The energy budget of a child can be up to 21 W/m² higher than adults in hot summertime conditions, and 26 W/m² lower in cold conditions. The model was validated through field studies of 65 children (32 boys and 33 girls) aged from 7-12 years old in 9 days from March to June in 2019, in 68 different microclimates ranging from cool to hot. A 5-point thermal comfort scale of energy budget for children was created using multinomial logistic regression, which revealed that children have a different range of thermal acceptability than adults. The frequency distribution of the actual thermal sensation and the predicted thermal comfort was improved using the new scale. The actual thermal sensation responses from children and the predicted thermal sensation using the model was determined to be positively significantly related. The accuracy of the model was 93.26%. This study has provided an effective children's energy budget model to predict children's thermal comfort. Its application can contribute to the design of thermally comfortable children's outdoor play areas by landscape architects and urban designers.