Upper-room ultraviolet germicidal irradiation (UVGI) is an air-purification technique. The system places special ultraviolet (UV) lamps in the upper region of a space to expose air to their light, while protecting the occupants below from exposure. A building engineer or maintenance supervisor would likely know if and what type of UVGI is being used in a space.
When carefully designed to provide appropriate radiation dosage, upper-room UVGI can effectively deactivate virus in the upper region of the room before being mixed back into the occupied zone below. This technology is most effective with Type 1 or Type 2 mixing type systems. It is less effective for Type 3 or Type 4 displacement or underfloor systems.
Like air-cleaning devices, upper-room ultraviolet germicidal irradiation (UVGI) must be carefully designed to ensure effectiveness. These systems often are brought to market without a universal method of test (MOT) from trusted authorities like ASHRAE. For these products, manufacturers are left to find their own path to demonstrate performance and assure users that they do not produce harmful byproducts. Some of these assessments are scientifically rigorous, while others are not.
For the time being, ParticleOne does not support or endorse innovative broad disinfection of the occupied zone using UVGI, so called “far UVC” systems. In our opinion, these systems are unproven in terms of effectiveness and have the potential for negative consequence or outcomes.