HVAC Best Practices During A Pandemic

Mar 17, 2020 10:31:00 AM | 3 minute read


Written by Rick Watts

Customer facing businesses, like retailers, restaurants, convenience stores and grocery stores, across the U.S. are ramping up their sanitation efforts to keep their facilities safe and clean during the COVID-19 pandemic. Many have established strict directives for dealing with this unique crisis, including implementing personal sanitation protocols, increasing their delivery and take-out options, and taking extraordinary efforts to deep-clean all surfaces and equipment.

One potential vulnerability that is being overlooked, however, are the facilities’ HVAC systems. Yes, COVID-19 is largely a physical contact threat that is primarily spread by coming in contact with someone who is sick or by touching contaminated surfaces. But recent research from a number of universities and research institutions indicates that the virus can survive in the air for hours. In enclosed environments like a convenience store or fast-casual restaurant, ventilation systems that cannot adequately prevent or filter pathogens before being inhaled may contribute to the contagion’s spread.

There are three fast, simple and relatively affordable remediation steps that store and restaurant owners can implement right away to allay consumer and employee fears about potential airborne pathogens in their facilities.



The spread of contamination is influenced by particulate size. Larger droplets will fall to the floor or on surfaces due to gravity. But smaller particulates – typically under 20 micrometers – can stay airborne for long periods.  

Increasing dilution of the air aims to diminish the concentration of smaller airborne particulates entering and circulating within the building. It can be achieved by introducing more outside air in a controlled way, supplemented with increased exhaust flow. We recommend increasing the rate of outside air to up to 50% to increase air movement and turn over the volume more quickly, continuously refreshing old air with fresh. 

Diluting the air reduces a person’s exposure time to potential infectious particulates. The less concentration of infectious particulates, the less chance of exposure. Business owners should continuously monitor their facilities for changes in air movements and changes, and adjust as necessary.



Any air filter that removes particulates from the air has the potential to reduce exposure to COVID-19. As businesses increase the air turnover in their facilities, they should also filter the airflows more aggressively.

The first step is to increase the filtration rating. The current industry standard for commercial HVAC systems in stores and restaurants is to use filters with a MERV 8 rating. We recommend replacing these with MERV 13-rated filters, which are designed to filter airborne viruses and bacteria when people cough and sneeze.

Using even higher-rated filters than MERV 13 could cause unintended circumstances. For instance, HEPA filters, which are commonly used in healthcare facilities because of their exceptional ability to trap very small particles, would be impractical for a commercial HVAC system because they would increase the static pressure and workload on the motors, leading to premature failure.

Beyond upgrading the filters, businesses should also increase the frequency at which they replace filters during this pandemic. If a business typically changes filters on a quarterly cycle, it should increase it to every 30 days, for example.



Ultraviolet disinfection for HVAC systems would typically be considered excessive for a retail or restaurant operation. But in these unusual times, they might be worth considering upon thorough research as to whether it’s an option for your business.

UV disinfection systems use germicidal wavelength irradiation to destroy infectious pathogens that collect on HVAC air ducts, evaporator coils and other components. They have the potential to destroy microbes that escape through air filters.

But UV treatment may not be practical for all businesses. You need to weigh cost and installation trade-offs. For example, equipping a multi-store chain with hundreds or even thousands of locations with UV disinfection capabilities could take a year or more to implement, along with a huge capital investment.

So far, retail and restaurant businesses have been admirably proactive in their efforts to keep ill employees away, implement more rigid personal hygiene protocols, and take extra steps to disinfect their facilities. But the air is out of sight and, thus, often out mind. Addressing airborne contamination will be an essential step in turning fearful consumers back to loyal patrons.

Explore Topics in FM: COVID-19 HVAC Rapid Response Planning