Experimental study on the control effect of the coupling effect of micro-differential pressure and ventilation system on indoor particulate matter migration

Abstract

The creation of micro-pressure differences (MPDs) is an important strategy in indoor environments control, especially in medical isolation wards and residential buildings. To better understand the role of MPDs, this study systematically investigated the effect of MPDs on the control of particulate matter (PM) exposure in a full-scale experimental chamber, taking into account the pollutant source location, door opening and closing, and human walking factors. A negative pressure (NA) combined with positive pressure (PA) system was set up to further investigate the coupling effect of MPD and the ventilation system. Results showed that the creation of MPD significantly reduced the dispersion of PM, where the cumulative exposure level (CEL) was reduced by 61.5 % from the baseline when the source was located in NA. When the source was located in PA, the form of airflow organization had a significant effect on the performance of the coupling system. The side supply and side return airflows performed best, with relatively lower CEL value (6.06–7.29 × 10⁷ particles cm⁻³) and the highest robustness (DR: 0.88) for door opening and closing and walking cases. In addition, the traditional metric (CEL, Welly-Riley equation) and new metric (robustness analysis: both PM removal efficiency and walking disturbance control effects) for evaluating ventilation systems were compared, and the Welly-Riley equation was used to correct the weights assigned to PM removal and walking disturbance in the robustness calculations. The highly stable ventilation configuration derived from the above metrics can provide design references for medical isolation wards and residential buildings.