Effect of the air intake height on the fresh air load of megatall buildings in the cold region of China

The new generation of tall buildings is going much higher than before. This paper evaluates the effect of air intake height on the fresh air load for the plan of constructing thousand-meter scale megatall buildings in the cold region of China. The central difference from the conventional research is the consideration of vertical variations of outdoor atmospheric parameters around the air intakes at higher levels, and a mesoscale meteorological model, Weather Research & Forecasting Model (WRFv3.4), is introduced into this research to explore the vertical variation trend of atmospheric parameters in the cold region. Additionally, considering the common feature of cold region, the evaluation is illustrated based on the representative coastal and continental locations, as represented by Dalian and Beijing City in the region. The results indicate that the fresh air loads for heating and cooling increase approximately +0.15 W·m−3·100·m−1 and −0.8 W·m−3·100·m−1 with air intake height, respectively. Furthermore, the optimal air intake height is analyzed from the perspective of the minimum fresh air load. It is revealed that the comprehensive fresh air loads with different ratios of the heating period to the whole conditioning period have the minimum value when air intake is placed at the height of 1000 meters (m). The results in this paper can be exploited to reduce the energy consumption of fresh air system in the megatall buildings constructed in the cold region.