STUDIES ON TRANSIENT THERMO-PHYSIOLOGICAL RESPONSE OF PASSENGERS IN AIRPORT TERMINAL BUILDINGS

Abstract

Airport terminal buildings (ATB) have evolved from a simple transit infrastructure into commerce coupled mixed-use facilities. Passengers perform a series of activities while transitioning through the ATBs due to which their body remains predominantly in a transient thermal state. As passengers navigate the terminal building, their metabolic activities intensify over extended periods of walking and standing, leading to a rise in internal heat production. This results in variations of sensible to evaporative heat loss ratios across different terminal zones contributing to differing thermal sensations experienced by passengers. Appropriate desing and operation of HVAC systems for maintaining optimal thermal environment in the terminal building is crucial for passenger satisfaction and well-being. The thesis investigates the dynamic interactions between human body and the indoor thermal environment within ATBs through a rational approach utilising human physiological responses. The study commenced with field studies involving real-time measurement of indoor environmental conditions in ATBs, registering subjective thermal response, and passenger flow & activity surveys. The study formulates an agent-based passenger flow model for establishing the dynamics of occupancy pattern, sequences of passenger movement and the resultant metabolic transience. The outcomes of the passenger flow model was utilised for thermo-physiological modelling of passenger sequence in the terminal building to establish the heat budget. Human heat budget within the ATB is evaluated through coupled thermo-physiological simulations of high-fidelity human models in the thermal environment replicating the conditions of the terminal building. The sensible and latent heat gains across various zones of ATBs during peak and off-peak times are established and compared with the values presented by ASHRAE and CIBSE standards. Further, human subjects simulated the passenger sequence in the climate-controlled chamber, and physiological responses were measured to obtain the dynamics of human heat exchange. Experiments were conducted to investigate the effect of elevated metabolic activities on human heat exchange. Similarly, experiments were performed to test the effect of changes in environmental conditions on the human heat balance. These tests were conducted for various combinations of metabolic activities, duration of activities, and changes in the thermal environment. Skin and core temperature, metabolic rate, and heart rate were measured concurrently with the subjective responses of individual test subjects to obtain the heat balance. The study presents the physiological and thermal sensation responses, heat loss and calorimetric analysis. Based on the empirical data, the study derives mathematical equations to estimate the physiological responses during the transient phases. In addition, the study introduces a novel weighting factor for calculating the physiological response using steady-state data. The application of the findings are discussed in the context of HVAC system zoning and operation in ATBs.