What Retailers Need to Know About COVID-19 and HVAC

Under the pandemic’s ongoing public health and economic impact, retailers are being challenged to do everything possible to lower the risk of COVID-19 transmission in their indoor shopping areas and work environments.

HVAC – heating, ventilation and air-conditioning – systems can be a powerful tool to help minimize the risk of airborne pathogens. Upgrading and enhancing these systems can be one of many measures retail managers can take to bring a safer shopping experience to their customers and staff.

As the scientific and medical community learns more about COVID-19 every day, the consensus remains that airborne transmission is the primary mode by which the disease is spreading. In addition to requiring masks and taking other precautionary sanitization measures, retailers can also upgrade their HVAC systems with emerging technologies shown to amplify their effectiveness in cleaning the air.

Every retail environment will have its own unique needs and opportunities to upgrade and equip HVAC systems to aid in the fight against COVID-19. The type of existing HVAC system that is being used, as well as the size, layout, coding regulations, and structure of the retail space, are all factors that must be considered. 

Fortunately, there are a range of existing and emerging HVAC technologies that can be added to existing HVAC systems to improve indoor air quality. Ideally, these technologies should be evaluated in consultation with a trained HVAC professional to ensure that they will work for the individual needs of each retail store environment.   

Air Ionization

Also known as bipolar ionization, air ionization is gaining greater adoption as a tool to remove airborne pathogens from indoor air.  On a molecular level, air ionization works by using high-voltage electrodes that separate oxygen molecules into negative and positive ions.  As these destabilized ions circulate through the air, they attach themselves to airborne pathogens, and neutralize them.  Within a continuously circulating HVAC system, these enlarged molecules are trapped in an air filter and removed from the air. 

Air ionization units can be a cost-effective and relatively easy-to-integrate into most existing commercial HVAC system. 

UV-C Lighting

Ultraviolet (UV) light can be a powerful tool in not only disinfecting surfaces, but also in purifying the air with the proper equipment and installation methods. UV-C light at a  germicidal wavelength of 260nm is considered the most effective in destroying pathogens. 

While it is harmful to human when direct exposure occurs, HVAC engineers can design and install equipment that will maximize its disinfecting power while keeping humans safe from its negative effects.  A newer version of UV-C light termed FAR-UVC is emitted at a wavelength that does not cause harm to humans and is still very potent in destroying virus particles.

Expert HVAC technicians can position and install the UV-C lighting within the HVAC ductwork, where the airborne particles that contain the virus will recirculate and become irradiated.  Maintenance is key to ensuring that ultraviolet lights are functioning efficiently and they generally should be replaced on an annual basis.

Air Filtration

Proper air filtration is fundamental to healthy indoor quality and may help lower the risk of airborne transmission of COVID-19.  Standard air filters have varying degrees of filtration efficiency, based on their minimum efficiency reporting value (MERV), which is a numerical value ranging from 1 to 16. The higher the number, the higher level of filtration it will provide as part of the HVAC system. 

The American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE) recommends air filters with MERV of 14 or higher in order to block airborne viruses.  Higher grade filters such as HEPA (high-efficiency particulate air) and ULPA (ultra-low particulate air) filters can provide stronger air filtration to remove viruses and bacteria from indoor air.  It’s important to consult with an HVAC professional before upgrading filters to ensure that the existing fan and motor systems can handle increased air pressure. 

Humidity Control

Humidity levels fluctuate throughout the year and vary dramatically region-by-region. Controlling humidity is important not only for the comfort of shoppers and staff.  It may also help to minimize the possibility of airborne transmission of COVID-19. 

Based on recommendations from the American Society for Microbiology, maintaining indoor relative humidity in between 40% and 60% creates an environment that is less conducive to airborne transmission of COVID-19, and it can help the body to ward off the virus by hydrating mucous membranes which help filter inhaled air. 

Depending on the needs of the indoor space, retailers can increase humidity, particularly during the winter months, by installing a humidifier within their HVAC system, or they can explore how best to lower humidity by consulting with a qualified HVAC professional. 

High Ventilation

While proper ventilation cannot prevent COVID-19 transmission on its own, it can serve as one of many key contributors to healthy indoor air quality. Published research has shown that indoor air quality is greatly enhanced when a higher than normal amount of conditioned outdoor air is circulated into an indoor air environment. 

Retailers can improve indoor ventilation by having an air economizer installed within the building’s HVAC system or they can add a dedicated outdoor air system (DOAS) to their system, also commonly known as a make-up air unit.  Experienced HVAC contractors can reprogram the HVAC controllers to increase the quantity of fresh air permanently, or through frequent flushing cycles.  If the outdoor temperatures, air quality and humidity levels are appropriate, they may also be able to enhance ventilation by opening windows and doors to allow outdoor air to circulate inside.

As the pandemic continues to bring challenges to retail operations across the country, HVAC systems can provide a powerful tool to help protect their customers when they are used as a secondary measure and environmental control in tandem with other CDC-recommended protocols to reduce COVID-19 transmission. Retailers can make a difference with meaningful improvements and additions to their existing systems that can pay off significantly with enhanced safety and peace of mind. 

Clive Samuels is president at CoolSys Energy Designs, a division of CoolSys, a parent company of HVAC and refrigeration companies nationwide.