Ventilation strategy for controlling particulate matter control in moxibustion treatment rooms

Moxibustion clinics suffer from smoke pollution due to the combustion of moxa sticks, which poses a serious health hazard to indoor occupants. It is widely recognised that effective ventilation strategies are essential to reduce indoor pollution. This study aims to systematically evaluate the effectiveness of displacement ventilation (DV) and mixing ventilation (MV) in controlling particulate matter (PM) concentration and to investigate effective ventilation strategies for PM control in moxibustion environments. The results show that the DV system can significantly reduce the PM concentration in the personnel breathing zone (0.8–1.8 m) by thermal stratification compared with the MV system, and air supply (Qv) and the ceiling height (H) have a synergistic effect on PM concentration control in the DV system. In the DV system, the PM concentration is initially reduced significantly with the increase of the Qv, and as Qv continues to increase, the higher the H, the earlier the PM concentration reaches a terminal value, and the stronger the stratification effect. It is recommended to apply the DV system with H ≥ 3 m and hti ≥ 1.8 m for Qv ≥ 80 L/s in a moxibustion environment. This study may be helpful for designing ventilation systems in moxibustion environments.