Empty building? Now is the time to upgrade your HVAC system for better air quality

Op-Ed Featured in Daily Journal of Commerce by Gus Simonds:

With COVID-19 surging again, I am hearing from landlords and commercial building owners who want to take the time during the latest shutdown to do all they can to prepare their buildings to safely welcome employees and customers back inside. Many employees have been working from home since March because of COVID-19 fears. Ten months later, companies want to bring them back — to benefit from team collaboration, face-to-face contact and camaraderie. They also are anxious to welcome customers back in.

The key consideration, of course, is safety since we know the virus is airborne and spreads more easily indoors. To make sure inside air is as safe to breathe as clean outside air, the American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE) recommends the following solutions:

1. Adjust building ventilation to bring in more outside air. ASHRAE recommends three changes of outdoor air before people come back into a building. Air should be completely flushed at the end of the workday so that employees or students return to clean air the next morning. When people are in the building, air should be flushed more often than in the past, even if it uses more energy and makes occupants a bit uncomfortable because of temperature and humidity fluctuations.

2. Control humidity. A study published in the journal PLOS One showed that maintaining humidity levels above 43% cuts the ability of viruses like the flu to spread. While few local buildings have humidity controls, another solution is to place portable humidifiers in high-traffic areas such as a lobby or entrance — especially in the drier winter months.

3. Increase filtration to remove as many virus-collecting particles from the air as possible. Replace filters often with the finest ones that a system will allow. Filters are rated MERV 1 to 20. MERV 13+ filters are recommended for COVID-19. For systems that can’t accommodate MERV 13 filters, MERV 11 filters are the next best choice. HEPA filters also work to arrest very fine particles, but retrofitting an HVAC system not designed for HEPA filtration is difficult. Instead of replacing an entire system, consider setting up a smaller, recirculating HEPA filtration system in high-traffic areas such as a lobby or building entrance.

Some businesses, nonprofits and municipalities have already taken the necessary steps to improve their buildings.

The city of Auburn, for example, has been very proactive in making sure the air inside its buildings — from the Justice Center to the Senior Center to the Humane Society to City Hall and even the airport — is as safe as can be for employees and visitors during the COVID-19 crisis. Auburn recently installed new state-of-the-art biopolar ionization units in the 18 buildings it runs.

In addition to using the COVID shutdown to retrofit their HVAC systems with additional filtration, flushing systems and humidifiers, other landlords and building owners are also using “smart building” technology to remotely monitor systems inside unoccupied buildings to make sure the systems are running safely and efficiently.

King County Library System, with 49 branches throughout the county, upgraded the filters in building HVAC systems to a version that traps smaller air particles and droplets. In addition, the interior air is being replaced much more frequently throughout the day with fresh outside air. Each night the air in those buildings is also replaced. And even when buildings are unoccupied, library facilities staff can monitor many of the library system’s buildings remotely to adjust the HVAC systems and keep track of discrepancies in the buildings if something is going wrong, or if the buildings are using too much energy. These efforts have allowed the library system to safely keep staff working in buildings, providing contactless curbside services for patrons.

Many local restaurants have also made changes — doing everything they can to prepare to welcome customers back inside. Schwartz Brothers, for example, installed new filters at its Leschi and South Lake Union Daniel’s Broiler restaurants and installed an entire new HVAC system at its Bellevue location. The air inside the Bellevue restaurant is turned over seven to 12 times an hour or more to help protect indoor diners.

It is true that all of these efforts increase energy use. Building owners have had to make the tough choice to put the safety of their employees and customers above conservation efforts at this time. But being able to monitor building systems remotely can help mitigate the cost.

All of these solutions, used in conjunction with face masks and proper social distancing, will increase the safety of working indoors. They offer ways for landlords to visibly show tenants and employees that they are being proactive in reducing the risk for workers and customers to come inside to help get our economy humming again.


Learn more about MacDonald-Miller’s services here: Indoor Air Quality during COVID-19.

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