Modeling heat loss through sweating: Towards improved heat load prediction from child occupants

• Developing a specific heat balance model for child occupants. • Children’s heat loss through sweating differs significantly from that of adults for the same activity. • No significant difference in skin temperature between children and adults. • Sweating response might be more significantly influenced by environmental conditions than by metabolic heat production. The design of HVAC systems requires correct estimation of both sensible and latent heat gains from occupants in order to assess cooling loads. Children differ significantly from adults in their heat production and thermoregulation in part due to variations in body mass, height, and sweat gland development, resulting in a unique sensible heat ratio for children. Though in spaces such as school classrooms and gymnasiums or daycares, children are the dominant occupant group, they are absent from load tables documenting the rate of net heat production by occupants and their sensible heat ratio. This study presents a steady-state, child-specific heat balance model, developed by modifying existing first-order thermodynamic equations from the literature to account for children’s unique anthropometric characteristics. Through a comprehensive search process, experimental data on children’s heat loss through sweating was gathered and analyzed. Statistical analysis of this data revealed the shortcomings of adult-based models in calculating the rate of evaporative heat loss through sweating per body surface area of children, even in mild environmental conditions. A novel regression model of the evaporative heat loss through sweating as a function of the air dry bulb temperature and net heat generation is proposed. This research lays the groundwork for the creation of comprehensive child-specific heat load tables, essential for optimizing HVAC systems in spaces designed for children.