Let’s Clear the Air: UV-C and HVAC

The idea of healthy buildings (and how HVAC systems contribute to them) existed for decades before the outbreak of the pandemic. But only in recent years did it become the rallying cry for many different sectors. The White House announcement this spring about the launch of the Clean Air in Buildings Challenge represents a call to action for anyone who manages or maintains a building. This challenge also places renewed focus on healthy buildings. As part of the launch, the Environmental Protection Agency released a practical guide for building managers, contractors, homeowners, and business owners to create an action plan for cleaner indoor air.

The healthy buildings movement also picked up steam with the publication of Healthy Buildings.  Written by Joseph Allen and John Macomber, this book’s release in 2020 couldn’t have been more perfectly timed. The world had awakened to the fact that our indoor environments contribute significantly to our health and wellbeing, and that unhealthy indoor air might be contributing to illnesses. In an April 2021 article in JAMA Insights, Dr. Allen identified methods for controlling the spread of airborne microorganisms. He noted, “Controlling concentrations of indoor respiratory aerosols to reduce airborne transmission of infectious agents is critical and can be achieved through source control (masking, physical distancing) and engineering controls (ventilation and filtration).”

The Role of HVAC

Engineering controls are “grounded in the basics of exposure science and inhalation dose risk reduction. Higher ventilation and filtration rates more rapidly remove particles from indoor air, thereby reducing the intensity of exposure and duration that respiratory aerosols stay aloft inside a room.”  Essentially, research indicates that exchanging the air in a room more frequently helps to reduce potential exposure to airborne viruses, germs, and other microbes. 

One of the most recommended weapons for dealing with indoor air quality is improved ventilation via heating, ventilation, and air conditioning (HVAC). Most buildings already have some form of an HVAC system. The standard system recycles the air somewhere between three and eight times per hour. Cycles depend on the building type, occupancy, and other factors. Organizations such as the EPA, the American Institute of Architects (AIA), and the American Society of Heating, Refrigeration, and Air-Conditioning Engineers (ASHRAE) determine these factors. These organizations have played a vital role in the growth of the healthy buildings movement. Consequently, HVAC has been a leading component of healthy buildings strategies and the push for improved indoor air quality.

In recent years, many companies have opted to replace or retrofit their HVAC systems to improve the indoor air quality of their facilities. HVAC air filters receive ratings that measure Minimum Efficiency Reporting Value (MERV). This rating identifies the filter’s ability to trap particles based on their size. ASHRAE developed the testing methodology that informs the rating system. The rating helps determine which system will work best for a given situation.

The MERV rating runs on a scale from 1 to 16. Filter ratings indicate the filter’s ability to capture particles that range in size from 0.3 and 10 microns. For most buildings, filters with a MERV rating between 8 and 13 will sufficiently filter the air. 

Moving Beyond Temperature Control

Humans have long sought to improve the temperature and air quality of their buildings. Even primitive cultures knew the desire to control temperature. Methods of heating a building existed as far back as the Iron Age (around 1200 BC). The modern concept for HVAC began around 1902 when Willis Carrier, a 25-year-old engineer in New York, invented modern air conditioning that moved air through water-cooled coils. 

Today, companies want more than just control over the temperature in their buildings. They want their HVAC to help keep the air free from allergens, odors, and microorganisms in their offices. Unfortunately, upgrading to high-end systems can be out of reach for many businesses. Furthermore, the age of buildings and the expense or impracticality of removing or altering existing equipment can also inhibit change.

When looking at other options for upgrading facilities and protecting occupants in their building, cost tops the list of concerns. Replacing such a large HVAC system can be cost-prohibitive. One estimate puts the expense at $22 per square foot for just materials. Older buildings tend to be more expensive due to their design or complicated issues.

As concern grows over airborne viruses, germs, and other dangerous microbial organisms, business owners and facilities managers continue looking for alternatives to help them fight against these invisible threats. Fortunately, there are options available to help in the fight against dangerous microorganisms that are more practical and less expensive or time-consuming than replacing an entire HVAC system. In fact, these options work in conjunction with HVAC to improve indoor air quality.

Improving Indoor Air Quality

UV-C technology has been proven to destroy or inactivate harmful microorganisms such as E. coli and Staphylococcus aureus. In a webinar hosted by R-Zero, leading researcher Dr. Edward Nardell, Professor in the Departments of Environmental Health and Immunology and Infectious Diseases at the Harvard T.H. Chan School of Public Health, spoke about how UV disinfection can be a valuable tool in indoor air quality. “It’s very important to know that virtually all [microorganisms] from viruses to even mold are vulnerable to germicidal UV because it damages the very core of life, RNA and DNA,” Dr. Nardell explained.

Dr. David Brenner, Director of the Center for Radiological Research at Columbia University, said the sensitivity of a virus to UV-C is due to the genomic size. According to Dr. Brenner, most human viruses have a similar genomic size. Therefore, the understanding is that all human viruses and variants will have a similar sensitivity to UV-C light. 

R-Zero’s Beam is an upper-room ultraviolet germicidal irradiation device (UVGI) that mounts near the ceiling of a room and inactivates airborne germs and viruses. Beam emits ultraviolet light at 265nm. This light inactivates 99.9% of certain airborne viruses and germs. Beam’s continuous, autonomous air disinfection equates to exchanging the air 12+ times per hour in a room. Beam can safely operate in occupied rooms. Beam’s operation can also adjust to accommodate the occupancy of the room, saving energy and money. The device has a built-in safety device that shuts down Beam in the event the light is interrupted.

For businesses and facilities, replacing or retrofitting the HVAC system isn’t the only way to ensure the indoor air quality in their buildings. Using a UVGI device such as Beam could be the answer to solving air disinfection needs without costly HVAC upgrades. R-Zero customizes solutions for each company so your air quality solution is unique to your needs. We invite you to learn more about the UV-C options best suited for your organization.