Hospitals use both UVC and HEPA filters to reduce viral infections (can use at home as well)
HEPA Filters in Hospitals
HEPA filters are the primary filtration technology in hospitals. These medical-grade filters (typically H13 and H14 ratings) capture 99.97-99.99% of airborne particles at 0.3 microns or larger. While influenza viruses themselves are tiny (0.08-0.12 microns), they don't travel alone through the air—they attach to larger respiratory droplets ranging from 0.5 to 5 microns, which HEPA filters effectively trap. medicair
In hospital settings, HEPA filters are essential components of Airborne Infection Isolation Rooms (AIIRs), where the filtered air prevents pathogens from escaping and contaminating other hospital areas. The CDC has recommended supplemental portable HEPA filters in high-risk hospital areas since at least 2003. hepacart
UV-C (Not UVB) Light in Hospitals
Hospitals also use UV-C germicidal ultraviolet (GUV) light, which is different from UVB. UV-C operates at wavelengths around 254 nm and 222 nm. Research shows UV-C is highly effective against influenza—studies demonstrate 99.999% reduction of influenza A (H1N1) virus when properly exposed to UV-C. light-sources
The CDC recognizes upper-room GUV systems as a supplemental ventilation intervention that inactivates airborne viral particles without removing them from the air. UV-C is particularly valued because it works continuously and can be used in occupied spaces when configured as upper-room systems (installed near the ceiling where direct human exposure is minimized). cdc
Clarification on "UVB"
To address your specific question: hospitals do not use UVB for flu control. UVB is a different wavelength (280-315 nm) associated with skin damage and is not used in medical air disinfection. What hospitals use is UV-C (100-280 nm), which is germicidal and safe for indoor use in properly designed systems.
Combined Approach
Hospitals typically deploy these technologies together: HEPA filtration as the primary air cleaning method, supplemented by UV-C systems for enhanced pathogen inactivation, particularly in high-risk areas. This combined approach, used alongside ventilation improvements and infection control practices, provides comprehensive protection against airborne respiratory pathogens including influenza. hepacart