It is true that a photocatalytic unit can inactivate microorganisms captured on the catalyst’s surface. However, in reality, existing photocatalytic units have a low rate of capturing (filtering) microorganisms, and a significant number of microorganisms pass through this unit. Hence, it has a low decontamination rate. Many manufacturers avoid this problem by installing devices that have a high capture (filtration) class before the photocatalytic units. But in this case it should be understood that the majority of microorganisms will settle on the filters and remain active, thus not entering the photocatalytic unit and not being inactivated. Thus, existing photocatalytic units either lack inactivation on the filters, which is contrary to SanPiN requirements, or have a low filtration (and air decontamination) efficiency. Additionally, photocatalytic units always contain UV lamps, and this significantly increases power consumption and maintenance service costs. The Tion active HEPA filtering technology is free of these disadvantages, since they always provide high-efficiency filtration in accordance with the regulations, and also inactivate microorganisms on the filters. At the same time, Tion units do not contain UV lamps, which significantly reduces equipment maintenance costs.