空调通风系统对室内微生物气溶胶的影响

Influence of air conditioning and mechanical ventilation(ACMV) systems on indoor microbial aerosols

现代建筑中的空调通风系统不可避免地接触输送到室内环境的空气,而该系统对微生物空气质量的影响直接关系到室内人员的健康.本文通过对大量的相关文献进行总结与归纳,将空调通风系统对微生物气溶胶的影响分为两种:一是空调通风系统的主要组分对微生物气溶胶的影响,具体指其组分直接降低或者增加室内微生物气溶胶的浓度;另一个是空调通风系统在运行过程中对室内微生物气溶胶的影响,既包括通风率、气流组织等参数对微生物气溶胶的影响,也包括该系统作为一条通道可将空气中已有的微生物从某一室内环境扩散到更多的室内环境.另外,本文通过分析空调通风系统污染室内空气的条件(如组分周围的物理和化学环境条件),提出相应的控制措施,如定期清理过滤器和通风管道等组分、及时去除热交换器和加湿器上的水分等,可以减少空调通风系统引起的微生物污染,从而保护室内人员的健康.

It is by now well established that most humans spend 70%–90% of their time in the mechanically ventilated buildings, in which the air conditioning and ventilation（ACMV） systems are commonly employed to provide fresh and clean air for indoor occupants. The air supplied to indoor environments inevitably passes over ACMV system and the interaction between the air and the ACMV surfaces can modify microbial air quality. Therefore, understanding how the ACMV influence biological aerosols can contribute to more incisive research to characterize indoor microbiology and associated health consequences. Such understanding is also essential for designing effective engineering controls to reduce bioaerosol exposure risks. In this systematic review, the content is organized into two main sections. In Part one—Influence of ACMV major components on indoor bioaerosol, commonly means the components could directly reduce or increase the indoor microbial bioaerosol concentrations. Except outdoor bioaerosols, the major components on the ACMV system could be also potential microbe＇s resources. In this part, we summarize how do the major components, such as filters, heat exchanger, cooling tower and ventilation ducts, influence indoor bioaerosols. In the meantime, we emphasized an inspirational consideration that the ACMV system as a direct pathway could also spread the existing indoor microbes into other more indoor environment. Part two（Influence to indoor bioaerosol by operation mode of ACMV） summarizes available information on many important processes of ACMV that could affect the concentrations and fates of indoor bioaerosol. This section begins by reviewing the state of knowledge regarding the factors related to the components themselves（design, material）; following with the factors related to the physical and chemical environment around the components（temperature, relative humidity, and airflow）. Then, the article proceeds to discuss several additional processes that can affect indoor bioaerosol levels： controlling the relative humidity of the ACMV system, selection of the appropriate ventilation rate, periodically cleaning the components such as filters and ventilation ducts, and removing moisture from the drain pan and heat exchanger accordingly. In the conclusion, important challenges facing further studies are described along with several opportunities for near-term progress advancing knowledge about indoor microbial aerosols along with the interaction of ACMV system. Such progress is fundamental to efforts to better understand how the micro biome of indoor environments interacts with human health and wellbeing.