Division of Global Health Equity, Brigham & Women's Hospital, Harvard Medical School, Boston, MA, USA.
Photochem Photobiol. 2021 May;97(3):493-497. doi: 10.1111/php.13421. Epub 2021 Apr 5.
Aerosol transmission is now widely accepted as the principal way that COVID-19 is spread, as has the importance of ventilation-natural and mechanical. But in other than healthcare facilities, mechanical ventilation is designed for comfort, not airborne infection control, and cannot achieve the 6 to 12 room air changes per hour recommended for airborne infection control. More efficient air filters have been recommended in ventilation ducts despite a lack of convincing evidence that SARS-CoV-2 virus spreads through ventilation systems. Most transmission appears to occur in rooms where both an infectious source COVID-19 case and other susceptible occupants share the same air. Only two established room-based technologies are available to supplement mechanical ventilation: portable room air cleaners and upper room germicidal UV air disinfection. Portable room air cleaners can be effective, but performance is limited by their clean air delivery rate relative to room volume. SARS-CoV-2 is highly susceptible to GUV, an 80-year-old technology that has been shown to safely, quietly, effectively and economically produce the equivalent of 10 to 20 or more air changes per hour under real life conditions. For these reasons, upper room GUV is the essential engineering intervention for reducing COVID-19 spread.
气溶胶传播现在被广泛认为是 COVID-19 传播的主要途径，通风——自然通风和机械通风的重要性也同样如此。但在医疗保健设施之外，机械通风是为了舒适而设计的，而不是为了控制空气传播感染，并且无法达到控制空气传播感染所需的每小时 6 到 12 次室内空气交换。尽管缺乏令人信服的证据表明 SARS-CoV-2 病毒通过通风系统传播，但仍建议在通风管道中使用更高效的空气过滤器。大多数传播似乎发生在有传染性传染源（COVID-19 病例）和其他易感者共享同一空气的房间中。只有两种已确立的基于房间的技术可用于补充机械通风：便携式房间空气净化器和上送风紫外线空气消毒器。便携式房间空气净化器可能有效，但性能受到其相对于房间体积的清洁空气输送率的限制。SARS-CoV-2 极易受到 GUV 的影响，GUV 是一种 80 年历史的技术，已被证明可在实际生活条件下安全、安静、有效地以经济的方式产生每小时 10 到 20 次或更多的空气交换。出于这些原因，上送风 GUV 是减少 COVID-19 传播的必要工程干预措施。
