Analysis of thermal comfort in a football stadium designed for hot and humid climates by CFD

Qatar is hosting the 2022 FIFA World Cup. In the field of sports architecture, this is a challenging case study for new design solutions that guarantee the comfort and safety of occupants in such a hot and humid climate. This work analyzes the thermal comfort of a stadium designed for international competitions in Doha, Qatar. The stadium has a total capacity of 47,000 spectators. An external facade protects the occupants from exposure to wind and sunlight, and fresh air and daylight enter the stadium through a semi-open roof. An air conditioning system controls the temperature and humidity on each stadium tier and on the football pitch. Air nozzles in the upper tiers exploit the buoyancy effect for the distribution of cool air, thereby saving energy. A steady-state, multi-region conjugate heat transfer model simulates the interaction between the building and environment using computational fluid dynamics. Six simulations are performed to investigate the thermal comfort in the stadium for different climatic conditions and duty cycles of the air conditioning system. All simulations measure the thermal sensation in the stadium's sectors based on the predicted mean vote and percentage of persons dissatisfied. They also assess the wet-bulb global temperature (WBGT) on the football pitch for the safety of the players, as required by FIFA guidelines. The results reveal that, for an external temperature of up to 48 degrees C and relative humidity of 70%, the air conditioning system guarantees a sensation of thermal neutrality, and the WBGT remains within the safety limit. When the cooling load is reduced by approximately 50%, most of the stadium's zones maintain thermal neutrality, and the risk of thermal stress to the players remains acceptable. Our research findings identify the conditions necessary to ensure a neutral thermal sensation in semi-open sport architectures, even in an extreme climate with high risk of thermal stress for the occupants.