Diagnosis of infectious cases and their isolation is a critical intervention, but transmission from asymptomatic persons is believed to play an important role in community transmission. In the U.S. the Centers for Disease Control and Prevention (CDC) has recommended that everyone wear non-medical face covers to reduce spread by respiratory droplets, both large and small. Healthcare workers should wear well fitted respirators designed to exclude airborne particles, in addition to following all contact precautions. For the airborne component, ventilation, social distancing, and other means of air disinfection are expected to have a role. Natural ventilation outdoors and in homes can be highly effective where conditions are optimal in terms of airflow and temperature. Mechanical ventilation can be effective, but 6 to 12 air changes per hour (ACH) are recommended in general for air disinfection or dilution.

According to the IES, upper-room GUV air disinfection is a primary means of safe and highly effective air disinfection, provided it is planned, installed, commissioned, and maintained according to current international standards. GUV in-duct air disinfection has been their recommended secondary approach to treating any recirculated air. However with the advent of new technologies including LED and fiber optic as well as reflective technology we believe this will soon be elevated to a primary means of effective disinfection. A knowledgeable consultant is recommended. Room air cleaners, disinfecting air through HEPA filters, or other methods seem attractive, but their clean-air delivery rate when converted to room ACH is often trivial—no more than 1 or 2 added ACH. GUV in-duct air disinfection is an approach to treating any recirculated air that has largely been underserved.