Optimizing thermal comfort in an atrium-structure library: On-site measurement and TRNSYS-CONTAM co-simulation

Atrium structures have been widely used in libraries to improve daylighting and architectural aesthetics. However, the possible greenhouse and chimney effects associated with an atrium may result in a large vertical temperature gradient and reduce the comfort of the indoor environment. In this study, on-site thermal measurements and a questionnaire survey on indoor satisfaction (2200 questionnaires in total) in four seasons at a library with two atriums were conducted. The experimental results revealed an uneven vertical distribution of air temperature. In winter, the average temperature difference between the warmest and coldest floors of the library was 4.7 °C and the thermal environment dissatisfaction rate was 27 %. In other seasons, the dissatisfaction rate was 9–12 %. To address the above problem, a coupled TRNSYS-CONTAM method was further developed to accurately obtain the distribution of temperatures and annual load for each floor of the atrium building. For the measured and simulated temperature values in winter, an RMSE of 0.56–0.81 °C was achieved. An air supply volume migration coefficient K_i was introduced to reduce the vertical temperature difference by adjusting the supply air volume at each floor. Under the guidance of accurate simulation calculations, the temperature difference between the top and bottom of the library would be decreased by approximately 1.5 °C in summer and 2 °C in winter. This study demonstrates a viable approach to enhancing thermal comfort and energy efficiency in atrium buildings.