Human–body exergy balance in naturally ventilated buildings in tropical climates: A New thermodynamic perspective on thermal comfort

This study investigates human–body exergy consumption (HBXC) in naturally ventilated building under hot–humid tropical conditions, addressing the critical knowledge gap in applying thermodynamic exergy principles where conventional comfort models often inadequately predict occupant satisfaction. Field measurements were conducted in a prototype naturally ventilated house, combining continuous environmental monitoring with real–time thermal sensation surveys from participants. The methodology applies Shukuya's unsteady–state exergy balance model to quantify radiant, convective, and evaporative heat transfers and the associated exergy flows. Results showed that HBXC rate values ranged between 2.1 and 3.4 W/m 2 , with evaporative exergy playing a dominant role, contributing up to ten times more than convective exergy. Window opening significantly influenced radiant exergy transfer, while fan operation stabilized convective heat exchange. Survey responses indicated that most participants felt comfortable, with minimal desire to change their thermal environment. The originality of this study lies in linking analysis with adaptive thermal comfort through empirical evidence from the tropics, where such exergy–based analyses are limited. Practical implications indicate that passive design strategies enhancing evaporative and radiant heat exchange, including strategic window placement and natural ventilation optimization can reduce dependence on mechanical cooling, improve indoor comfort, and support resilient, energy–efficient building design in hot–humid climates. • Human responses to indoor thermal comfort in hot humid buildings are analyzed. • Human–body exergy consumption is examined in relation to thermal preference. • Indoor airflow influences radiant and convective exergy exchange mechanisms. • Evaporative cooling plays a dominant role in human-body exergy balance.