Equivalent contact temperature (ECT) for personal comfort assessment – definition of comfort limits for winter conditions

This article revisits the Equivalent Contact Temperature (ECT) model by incorporating winter scenarios with seat heating, which were unaddressed in previous studies. The research focuses on enhancing the model's accuracy in evaluating thermal comfort for seated individuals under non-uniform conditions, particularly for the buttocks and back. These contact areas are crucial for both local and overall comfort, especially with Personalised Environmental Control Systems (PECS), like seat heating and ventilation, which operate close to the body. PECS are more energy efficient than traditional HVAC systems, offering customisation to individual comfort preferences while enhancing individual thermal comfort and energy efficiency in buildings and vehicles. A participant study at air temperatures of 17 °C and 18 °C validated the ECT approach, confirming the effectiveness of seat heating and revealing key correlations between ECT values and thermal comfort ratings. Additionally, an equivalent skin temperature and a comfort evaluation scheme for winter conditions were introduced.