The COVID-19 pandemic changed almost everything for institutional and commercial facilities. The impact on HVAC systems in particular was immediate, and three years later, building owners and facility managers are still dealing with the pandemic’s fallout on the technology, products and processes that affect indoor health for facilities and occupants.
No elements of HVAC systems and processes have come under more scrutiny since March 2020 than air filtration and ventilation. The general public took a sudden interest in such issues as MERV ratings for filters and outdoor air ventilation rates, and facility managers took center stage for organizations trying to answer tough questions while creating healthy indoor environments.
“The two key changes that I've seen as a result of the pandemic have come down to the overall public knowledge and awareness and questions about filtration and ventilation or outside air introduction in all of their buildings, whether they're at their office or their kids’ school or elsewhere,” says Benjamin Weerts, associate mechanical engineer with WSP, an engineering, environment and professional services firm. “Everybody seems more interested in learning about that and knowing that their space is being properly filtered and taken care of and they're getting adequate outside air or ventilation into all their spaces.”
Such discussions helped building operators and designers rethink the impact of HVAC system components and operations on human health and on even broader issues.
“I think we've had a much better understanding of the impact on health as related to ventilation and to HVAC systems,” says Laurie Gilmer, president and chief operating officer of Facility Engineering Associates. “It's something that we hadn't really thought of before. Certainly, the design community thinks about this, the sustainability community thinks about it, the O&M community thinks about it but all from different perspectives.
“When we say things like, ‘We'd like more outside air,’ there's an uncomfortable tension that's already there because outside air is inherently expensive to condition. It costs something to do that.”
These discussions often led to an overall reassessment of traditional HVAC system design and management.
"We talked about how to ensure improved indoor air quality, and in that conversation about filtration, everybody got a lot more aware and educated on the impact of filters and what the design might need to be,” Gilmer says. “On the design side and operation side, we used to put in lower grade filters because we were just trying to filter out things like dander and pollen and dust. We weren't as worried about the pm 2.5 and virus particulates because we viewed those as being in more specialized environments.” pm 2.5 refers to inhalable particulate matter with diameters generally 2.5 micrometers and smaller.
Three years later, the results of these discussions are playing out in facilities.
“A lot more buildings now are considering putting in that higher level of filtration, either retrofit or upfront in new designs to provide better air,” Weerts says. “In addition, there's increased ventilation air flow rate, which also can be considered in existing buildings. There are limitations with sizes of air handlers and fan power and what space you actually have. There are tradeoffs to bringing in more outside air and filtration to a higher level. It will cost more energy, but people now understand the higher value of that.”
Managers also have had to account for changes since 2020 in standards that affect air filtration and ventilation, such as ASHRAE Standard 241, Control of Infectious Aerosols. It establishes minimum requirements to reduce the risk of airborne disease transmission, such as SARS-COV-2 virus, which causes COVID-19, the flu virus and other pathogens. The standard applies to new and existing buildings and major renovations and provides requirements for air system design, installation, operation and maintenance.
Beyond ventilation and air filtration, managers also have taken a closer look at HVAC technology applications and advances since 2020 that are designed to address demands for healthier indoor air.
"One of the more prevalent things that I think is gaining popularity is UV-C light technology,” Weerts says. “It was always there, but people are more aware: ‘I can put this in my air handler, or I can mount this unit up high on the wall, and it will have the effect of sterilizing the air as it's moving through.’"
Gilmer offers UV systems as an example of the changing mindset of owners and managers.
“We were much more thoughtful in trying to figure out how to improve air quality when a system might have its own certain special set of limitations,” she says. “It did cause us to look at some emerging technologies like needlepoint bipolar ionization. I still would put it in the emerging technology arena, but the pandemic brought it forward as something to consider and test. The pandemic did cause us to look more broadly than our conventional methods.”
Nikki Hammer, P.E., vice president of market and innovation advisory services with WPS, points to additional examples of evolving technologies that are getting much closer looks.
“The prevalence of the Internet of Things and buildings finally being able to measure things that maybe 10 years ago they weren't able to measure,” she says, adding IAQ sensors to the list. “Indoor air pollution issues are a large part of the conversation. So (sensors) are measuring CO2, TVOC (total volatile organic compounds), all the things that they're set to measure, and more clients want those installed within their buildings. Oftentimes, we'll put one outside of the outside air intake so we understand the baseline outdoor air quality, and then we understand the indoor air quality. With that, we can start to make some decisions about how we're cycling our HVAC within the space.”
As new ideas continue to emerge about filtration, ventilation and HVAC system management three years after COVID struck, perhaps the most important change has occurred in the minds of building owners and managers responsible for providing healthy indoor environments.
“Before the pandemic, air quality was an amenity the same way free food, having a rock climbing wall, offering free yoga classes, and having a healthy building were amenities that they could use to attract the best people,” Hammer says. “What's changed during the pandemic was that everybody started knocking on our door and saying, 'What do we need to do?’ The awareness changed. COVID changed things.”
Dan Hounsell is senior editor for the facilities market. He has more than 30 years of experience writing about facilities maintenance, engineering and management.
