A building industry consortium formed to address the COVID-19 epidemic is drawing up a return-to-work checklist for landlords and tenants, including HVAC system upgrades designed to kill or flush out viruses.

Landlords of now-deserted commercial buildings have a menu of options to fight the indoor transmission of COVID-19 as they prepare for a gradual return of tenants’ workforces, but face significant capital costs and no guarantee how effective they’ll be. 

The Boston Real Estate COVID Consortium, or BRECC, is studying how both behaviors and building systems are likely to change in the wake of the pandemic. Changes to HVAC systems are a key recommendation by the group, including more powerful filtration and air exchange systems, and newer innovations such as ultraviolet light fixtures that can kill viruses. 

“HVAC is number one,” said Denise Pied, co-founder of the group and a vice president at Newton-based STV/Diversified Project Management. “Changing outdoor air circulation and filtration systems is tens to hundreds of thousands of dollars for the hardware. If you’re in a high-rise building, that could get very costly, very quickly.” 

Masks, Distance Still a Must 

Even with building improvements, the consortium concluded that occupants will need to wear masks and maintain social distancing. 

The 16-member group which includes engineers, project managers and architects is developing a return-to-work checklist for building owners and tenants as they wrestle with ways to reoccupy buildings safely and instill confidence in those who work in them. New one-way foot traffic patterns, restricted points of entry and new partitions in common areas and tenant spaces will become widespread. 

As office tenants become adjusted to work-from-home routines and hesitate to sign long-term leases, they’ll have more leverage to demand upgrades than in recent years. 

Best practices will vary based upon the design of the existing building systems, but BRECC says landlords should consider multiple strategies due to their various limitations.

“Every lease is different, but if a tenant has a good lawyer they’ll get a third-party review from the engineering side understanding how the building operates,” Pied said. “That’s a good starting point to start that dialogue with the landlord.” 

Some leases already contain language on hours of operation for ventilation systems and specifications for filtration systems, which are rated based upon Minimum Efficiency Reporting Value (MERV). Requirements vary among jurisdictions and building codes, but most existing buildings are required to have MERV ratings from 6 to 8. 

Weighing a Series of Tradeoffs  

Health researchers say the coronavirus can linger as airborne particles for hours in enclosed spaces, making air exchange paramount. As businesses weigh whether and how soon to reopen offices, they should demand higher indoor air quality standards including 30 percent more outside air than required by code, the consortium recommends. 

“The more outside air, the better,” said Ray Doyle, managing principal at WB Engineers in Boston and a consortium member. “The first thing we’re telling everyone is dilution, ventilation and getting as much [outside] air as you can to get the bad particles out of the building and keep air moving.” 

That requires a series of trade-offs, both financial and logistical, building engineers say. In some buildings, increasing outdoor air flow is a simple matter of adjusting control panel settings. But the infusion of hot and humid air in the summer triggers higher energy consumption, Doyle said. 

Upgrading from a MERV-8 to MERV-13-rated filter equates to a 40 percent increase in effectiveness removing airborne flu viruses, the consortium said, but requires HVAC systems to work harder. And energy-efficient chilled beam systems in some newer buildings bring in air changes less frequently than conventional HVAC systems, and could require installation of supplemental air handling units. 

Newer technologies have shown potential for removing pathogens from indoor environments. Photocathotic oxidation systems installed at air handling units use heated layers of titanium wire mesh and ceramic coating, and have been proven effective against viruses and other air contaminants. Ionizers kill viruses and improve the performance of HVAC filters, but have unknown human health effects. And ultraviolet lamps installed at HVAC cooling coils can kill airborne viruses, too, but are less effective in cold weather. 

Steve Adams

Best practices will vary based upon the design of the existing building systems, but BRECC says landlords should consider multiple strategies due to their various limitations. 

Given the costs and drawbacks of capital improvements, the consortium also recommends a series of less intrusive short-term strategies. They include isolated foot traffic patterns, staggered work schedules, enhanced cleaning protocols and reduced office occupancy. 

“The source [of risk] is the people who come and go, and whether they wear masks and maintain six-foot spacing and use hand sanitizing, to prevent keeping the virus airborne in the first place,” said Stephen Rizzo, president of Wareham-based Synergy Consultants.