Recirculating air purification technologies are employed as potential means of reducing exposure to aerosol particles and airborne viruses. Toward improved testing of recirculating air purification units, we developed and applied a medium-scale single-pass wind tunnel test to examine the size-dependent collection of particles and the collection and inactivation of viable bovine coronavirus (BCoV, a betacoronavirus), porcine respiratory coronavirus (PRCV, an alphacoronavirus), and influenza A virus (IAV), by a commercial air purification unit. The tested unit, the Molekule Air Mini, incorporates a MERV 16 filter as well as a photoelectrochemical oxidating layer. It was found to have a collection efficiency above 95.8% for all tested particle diameters and flow rates, with collection efficiencies above 99% for supermicrometer particles with the minimum collection efficiency for particles smaller than 100 nm. For all three tested viruses, the physical tracer-based log reduction was near 2.0 (99% removal). Conversely, the viable virus log reductions were found to be near 4.0 for IAV, 3.0 for BCoV, and 2.5 for PRCV, suggesting additional inactivation in a virus family- and genus-specific manner. In total, this work describes a suite of test methods which can be used to rigorously evaluate the efficacy of recirculating air purification technologies.

中文翻译：

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基于风洞的光电化学氧化过滤器空气净化装置去除和灭活冠状病毒和流感气溶胶的测试


再循环空气净化技术被用作减少接触气溶胶颗粒和空气传播病毒的潜在手段。为了改进再循环空气净化装置的测试，我们开发并应用了中型单通道风洞测试，以检查颗粒大小依赖性的收集以及活牛冠状病毒（BCoV，一种β冠状病毒）、猪呼吸道病毒的收集和灭活。商业空气净化装置可清除冠状病毒（PRCV，一种α冠状病毒）和甲型流感病毒（IAV）。接受测试的 Molekule Air Mini 配备了 MERV 16 过滤器以及光电化学氧化层。结果发现，对于所有测试的粒径和流量，其收集效率均高于 95.8%，其中超微米颗粒的收集效率高于 99%，小于 100 nm 的颗粒收集效率最低。对于所有三种测试的病毒，基于物理跟踪器的日志减少量接近 2.0（去除 99%）。相反，IAV 的存活病毒对数减少量接近 4.0，BCoV 为 3.0，PRCV 为 2.5，这表明以病毒科和属特异性方式进一步灭活。总的来说，这项工作描述了一套测试方法，可用于严格评估再循环空气净化技术的功效。