Air change per hour improvement for positive and negative pressure mechanical ventilation facilities systems

Ventilation reduces indoor pollutants, and this issue has recently received attention. Most scholars adopt ventilation strategies to reduce energy consumption. While natural ventilation does not require ventilation facilities, it also brings many challenges, such as lack of external openings and insufficient air change per hour. Therefore, it is necessary to rely on mechanical ventilation to increase indoor air change per hour. However, mechanical ventilation comes with increased energy consumption, which poses a significant challenge to reducing energy usage at present.To improve energy usage, increase air changes per hour, and reduce the number of fans by half, we propose implementing positive and negative pressure ventilation indoors at the same airflow rate (3000 CMH). The research results showed that positive and negative pressure ventilation increased air changes per hour by 94 % and 62 %, respectively, while also reducing fan energy usage by 50 %. Through visualization, we also discovered the uneven distribution of indoor carbon dioxide levels. This breakthrough is of significant importance for current indoor mechanical ventilation systems and contributes greatly to future near-zero carbon emissions.