Air Distribution and Indoor Climate in a Multipurpose Arena

This study investigated a multipurpose arena located in Malmö, Sweden with a seating capacity of up to 13 000 individuals, and in which a combination of displacement and mixing ventilation was applied. The dimensions of the arena were 100 m (L) x 90 m (W) x 30 m (H) and the interior architecture was comprised of ice rink, seating area, cabinet region and building envelope with structures. The objective was to investigate thermal conditions, indoor air quality, thermal comfort, airflow patterns and ventilation performance. The measured operating conditions were ice hockey game, training session and maintenance situation. The research methods were CFD-simulation and experimental measurements. The measurements were conducted with air speed, temperature and humidity sensors, and by taking thermal images and visualizing with smoke. CFD-simulations were performed to investigate the arena flow field. It was found that the primary air movement is complicated and case-dependent. The temperature rise was only 2ºC during the game and the temperature stratification was small. Furthermore, the temperature level was 13-17ºC at the lower-seating area and 15-17ºC at the upper-seating area. The corresponding air speeds were below 0.25 m/s and 0.3 m/s, respectively. The relative humidity was 30-45% and the carbon dioxide content did rise by up to 300 ppm during the game, increasing the total to nearly 900 ppm. The supply air temperature, variable air flow rates and retractable stands had a notable effect on the principal air movement. The air distribution could possibly be improved by implementing individual ventilation and heating strategies.