Viola provides biological air treatment to prevent airborne infections in a safe, elegant and easy-to-use device. Viola can drastically reduce the microbial load in both public and residential spaces to create a safe environment for people to meet and work. Where similar devices are mostly based on the use of substances or methods that prohibit the presence of people, Viola works on the basis of a closed-loop ventilation system that cleans the air using UV-C radiation in an internal irradiation chamber. A custom set of grills expels clean air without ozone dispersion making it a safe and noise-free solution.