Reduced-scale experimental and numerical investigation on the energy and smoke control performance of natural ventilation systems in a high-rise atrium

Natural ventilation (NV) is an effective energy-saving strategy to remove the excessive heat in high-rise atria. The traditional NV system in high-rise atria has inlet openings at the bottom and outlet openings at the top. However, this traditional system may bring fire safety concerns due to the rapid spread of smoke during an atrium fire. To remove the fire safety concern, a new NV system was proposed in this study. This new system applies a segmentation slab to divide the high-rise atrium into upper and lower parts, which can limit the smoke movement. A ventilation shaft is installed to maintain the NV rate and extract smoke. To investigate the energy and smoke control performance of the new and traditional NV systems, a 1:20 small-scale experimental model and CFD numerical model were built. The results indicate that the new NV system with the shaft and segmentation can remove more heat than the traditional NV system. Furthermore, the new NV system can simplify the mechanical smoke exhaust system and improve the smoke control performance, e.g., requires a lower volumetric flow rate and maintains a thinner smoke layer