Thermal comfort conditions in airport terminal buildings

Airport terminals are characteristic for the large and open spaces with diverse and transient population. They are designed predominantly as indoor spaces while the overwhelming majority is people in transient conditions. Dressing code and activity, along with dwell time and overall expectations are differentiating factors for variations in thermal requirements between passengers and staff. The diversity of spaces and the heterogeneous functions across the different terminal zones further contribute to this differentiation, which results in thermal comfort conflicts and often in energy wastage.

Understanding such conflicts and the comfort requirements can improve thermal comfort conditions while reducing the energy consumed for the conditioning of these energy-intensive buildings. Through extensive field surveys, the study investigated the thermal comfort conditions in three airport terminals of different size and typology. The seasonal surveys included extensive environmental monitoring across the different terminal areas and over 3,000 questionnaire-guided interviews with passengers, staff, well-wishers and other short stay visitors.

The findings demonstrate a preference for a different thermal environment than the one experienced and that thermal neutrality lies at lower temperatures. The comfort requirements for passengers and staff are evaluated and shown to differ significantly. Neutral temperature for passengers is lower by 0.6 - 3.9 °C. In accordance with the neutrality discrepancies, passengers prefer cooler temperatures than staff by 0.4 - 2.0 °C. Employees have limited adaptive capacity that leads in a narrower comfort zone, whereas passengers consistently demonstrate higher tolerance of the thermal environment and a wider range of comfort temperatures. Furthermore, the findings highlight the complex nature of thermal comfort in airport terminals, where the desired thermal state for more than half the occupants is other than neutral and a multitude of design and operational characteristics influence the indoor environment.