A generation of research and experience has proven that when properly maintained and operated, heating, ventilation and air-conditioning systems (HVAC) can reduce the spread of viruses. These critical building systems not only provide thermal comfort but, according to the American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE), may also improve resistance to infection.

The American Society for Microbiology (ASM) has recently addressed the issue of COVID-19 transmission in buildings and other indoor settings in which most humans spend more than 90 percent of their daily lives. There are several major transmission factors that promote infection in these environments including occupant density, the amount of social activity and interaction, and human contact with surfaces. The cruise ship industry, nursing homes and prisons have taught us about the risk of transmission. However, we also have learned that proper handwashing, social distancing and wearing masks work to reduce transmission.

Alongside these primary factors, HVAC systems work in an indoor setting to supply comfortable, clean, recirculated air, healthy levels of fresh air, and contain or exhaust contaminants. Air delivery systems can reduce the transmission of viruses through inline filtration that HVAC professionals can assess.

Air-conditioning systems are also critical in maintaining healthy humidity levels. Maintaining a RH (relative humidity) between 40% and 60% indoors may help to limit the spread and survival of viruses the ASM suggests, while minimizing the risk of mold growth and maintaining hydrated and mucosal barriers of human occupants.

The Centers for Disease Control (CDC) echoes these findings, saying that employers can decrease the spread of COVID-19 by maintaining a healthy work environment. “Consider improving and engineering controls using the building ventilation system,” the CDC suggests, including increased ventilation rates and increased percentage of outdoor air circulating through the system.

Well before COVID-19, the Healthy Building Movement had begun to measure and improve air quality in buildings to improve productivity and health. Of the nine foundations for a healthy building, five relate to HVAC, including air quality, ventilation, thermal health, moisture, dust and pests. “There’s just no reason anymore to economize on airflow and filtration,” Harvard Business School says. “It’s a cheap way to help people be healthier.”

Contact our service manager, Alby Rule at albyr@qualityref.com or (310) 549-1532 x215 if you would like more information on improving indoor air quality at your facility.