Outdoor air supply in winter for large-space airport terminals: Air infiltration vs. mechanical ventilation

Abstract Excessive outdoor air supply in winter due to air infiltration is prevailing in large-space airport terminals, leading to high energy consumption for heating, while mechanical ventilation systems rarely operate to supply outdoor air during the heating season. This study applies a simplified model to analyze the strategies to effectively reduce the air infiltration rate and meanwhile fulfill the demand for outdoor air supply in large-space airport terminals during the heating season. The analysis of main influence factors helps to propose practical methods to reduce the air infiltration rate, i.e., adjust bottom openings, adjust upper openings, use radiant floor. The air infiltration rates can be controlled steadily at a low level (0.14–0.23 h−1) during the heating season by all the three methods. The designed outdoor air ventilation rate is averagely 0.22 h−1 in seven airport terminals without a dramatic difference. An analysis of a real airport terminal indicates that its designed outdoor air ventilation rate (0.20 h−1) largely exceeds the actual maximal demand (0.13 h−1) because of the uneven occupant distributions both in time and space. Therefore, even though the three methods are utilized to decrease the air infiltration rate and its corresponding heating load, the demand for outdoor air in large-space airport terminals can still be fulfilled during the heating season without mechanical ventilation.