Our understanding of the COVID-19 pandemic changes weekly. As we begin to return to our places of business, new guidance from the Centers for Disease Control & Prevention (CDC) indicates that transmission isn’t likely coming from contact with surfaces.
Air transmission is still the primary culprit it seems, and for property managers, beyond the distribution of masks that will be the unwritten law of the land for the foreseeable future, that points the conversation directly at our buildings’ HVAC systems. Justin Davidson, writing in a recent issue of the New York Magazine Intelligencer, puts it plainly: “At some point, we have to go back inside and face the question: Can I trust the air?” The short answer is yes . . . but it falls to property managers to ensure that trust. Davidson quotes Harvard public health professor Joseph Allen, who says that, when it comes to ensuring that trust and the top performance of their HVAC systems, “the building facilities team can and should be doing that, and they should share their plans and protocols.”
But you already knew that, especially if you’ve been keeping up with IREM guidance on the subject throughout the run of the pandemic. The guide is specific and to-the-point when it comes to ensuring indoor air quality:
- Determine current fresh and recycled air mix.
- Increase fresh air as possible.
- Change filters on outdoor and return air systems.
- Determine the highest MERV rating possible with the property’s HVAC system. Install filters with a MERV rating of at least 13 (minimum rating required to trap respiratory particles) if possible. Check the compatibility of HEPA filters (MERV rating 16+) with your system.
- Have duct systems cleaned and disinfected regularly.
- Obtain IAQ testing, including the analysis of particulate matter, for management-controlled areas.
- Explore the installation of IAQ monitoring equipment, including CO2 sensors, which can alert management to malfunctioning ventilation components.
For good measure you can add guidance from the American Society of Heating and Air-Conditioning Engineers (ASHAE):
- Create a strategic plan prior to opening a building. The plan should include measures to make occupants feel safer, including communication plans for building support and safety measures for occupants.
- Review HVAC programming to provide flushing two hours before and post occupancies. This includes operating the exhaust fans as well as opening outside air dampers. For buildings without the capacity to treat large quantities of outside air and when outside air conditions are moderate, open all windows for a minimum of two hours before reoccupation.
- Ensure that the custodial scope includes proper cleaning procedures built from EPA and CDC guidance on approved products and methods:
- Disinfect high-touch areas of HVAC and other building service systems (e.g. on/off switches, thermostats);
- Disinfect the interior of refrigerated devices (e.g. refrigerators, where the virus can potentially survive for long periods of time).
- Run the system on minimum outside air when unoccupied.
- Garage exhaust, if any, should run two hours before occupancy.
The group also recommends the development of a water-management plan to reduce the risk of bacteria growth that could have occurred during the low-usage periods of the quarantine.
“So the issue really is more than just COVID,” says James Scott, IREM’s Innovator in Residence and lead researcher for MIT’s Innovation Lab. “Most office spaces have been unoccupied for the past several months, which may have allowed dust, bacteria or mold to materialize in systems during this extended low-utilization period.”
How new software applications can play into this mix is hard to predict, Scott says, especially given that, as we have seen, our understanding of COVID, and therefore the protocols for dealing with the virus, change frequently. “What we do today may not be relevant in three months’ time and probably won’t be the right thing to do in six months’ time as more data comes through,” he says. “So the best we can do is be mindful of our best practices and current guidance.”
There are two ways to look at those protocols and practices. Rather than viewing the new–and always changing–expectations for our HVAC systems as an added responsibility, ASHRAE sees this guidance as an empowerment of property managers and owners to provide “safer operation of HVAC systems as we cautiously transition into a post-COVID-19 world.”