Almost immediately, reality began to chip away at Plan A. Some in the HVAC and retail industries observed that mall management must take existing systems into account. Plugging in a filter improper for the existing equipment could do more harm than good. Operators must take a different filter’s properties into account with regard to the system’s overall balance and performance.

Some malls, of course, would not be currently equipped for HEPA media, and accommodating that would require additional money and valuable time.

Merv-13 As The New Minimum

Based on subsequent study and input, the governor’s office revised its filtration requirement a week later as it announced requirements for malls in areas that had met criteria to enter Phase 4. In a July 10 announcement, Gov. Cuomo said that shopping malls of 800,000 square feet or more must have filters with MERV-13 ratings or better.

MORE PARTICULAR ON PARTICULATES: New York Governor Andrew M. Cuomo has adjusted mall HVAC requirements in an effort to balance occupant safety with existing mall system capabilities. At the least, reopening New York malls must use MERV-11 filters and pursue other criteria. Photo by Diana Robinson, CC 2.0.

Furthermore, if a property’s HVAC operation met other “enhanced” protective criteria, then MERV-11 filters could suffice.

Wilmorite owns four malls in the greater Rochester, New York, area, including Eastview Mall in Victor, New York. Its statement following the original June 29 governor’s briefing demonstrated one path for getting ahead of requirements and reassuring the public.

“The individual stores have their own systems, just as they do in strip centers and office parks,” Wilmorite stated. “Each mall property can be disabled from ‘Demand Ventilation Control,’ which controls the levels of CO₂ in the space, and all fresh air dampers will be opened to a predetermined set point. This will allow for a higher rate of outside air to the space.”

The company went on to explain that its BMS programming would adjust accordingly in managing ventilation. Wilmorite also pointed out recent upgrades, its regular preventive maintenance program, and the recordkeeping to support that program.

Increasing ventilation and outdoor air rates, adjusting dampers to reduce recirculation, and disabling demand control ventilation would all subsequently appear on New York’s revised criteria for enhanced ventilation status.

Malls that wanted to reopen July 10 but could not meet the MERV 13 requirement were told to compensate by achieving some of the above steps and/or other steps including: extending system run times (ideally around the clock), considering appropriately designed ultraviolet germicidal irradiation, and sealing filter edges to limit bypass.

The state’s requirement for malls smaller than 800,000 square feet specified that the building’s “HVAC system filtration meets the highest-rated filtration compatible with the currently installed filter rack and air handling systems,” reiterating MERV-11 as the minimum in any case and preferring MERV-13 if not HEPA.

Twenty Percent Is No Solution

New York’s revised guidelines did preserve the chances for many malls to reopen sooner, but practically any mall would still have adjustments to make, according to Omar Tabba. Tabba is vice president of products and solutions at BrainBox AI. His company offers AI solutions to automate HVAC operations. The idea in cases like this is to use artificial intelligence to implement ASHRAE recommended strategies more quickly while also incorporating variables like local weather, any presence of pollutants, and occupancy rates.

ELEVATED EXPECTATIONS: In addition to filter upgrades, extended hours of system operation and more outside air can cut down on the chances of spreading COVID-19.

Tabba noted that each mall starts from a different place — some use central plants, others may use rooftop units — and that 20 percent outdoor air has been “a common minimum that is seen in many jurisdictions.”

Now, malls would need to increase the outdoor air, preferably in conjunction with several other measures. Tabba used a car’s combined effect of seatbelt, airbags, bumpers, and sensors to improve occupant safety to support the idea that proper recirculation should work in tandem with other tactics.

Tabba emphasized the “low-hanging fruit solutions” that owners can employ that “can enable cleaner and safer air in buildings without the need to engage in huge system retrofits.”

Those steps can range from the recommended ASHRAE parameters to incorporating a product like BrainBox’s to reach those targets more quickly and better contain costs.

Where Do We Go From Here?

ASHRAE’S response to the New York requirements highlighted one guideline with some distinct contractor relevance.

“The mandatory guidelines,” ASHRAE summarized, “also require that system filtration requirements are certified and documented by a certified HVAC technician, professional or company, ASHRAE-certified professional, certified retro-commissioning professional, or New York-licensed professional building engineer.”

Opportunity to provide verification may await at properties like these (along with service agreement potential, depending on a given owner’s previous regimen). Contractors may also find that mandated professional attention is an opportunity to take advantage of existing relationships or build new ones.

Cleary Gottlieb Steen & Hamilton LLP has been tracking state actions along these lines for its clients. Litigation partner Jennifer Kennedy Park and Michael J. Albano, partner, created a table surveying the state-by-state situation in late July.

At the least, New Mexico, California, Colorado, and Minnesota have announced their own guidelines regarding HVAC system minimums, including professional consultation in some cases.

“Retail businesses may also want to note that the industry-specific guidelines are advisory, not mandatory, in many states,” said Park and Albano.

“That said, retailers should consider following advisory measures to ensure employee and patron safety, as well as to limit potential legal exposure.”

Back in New York, attention to the data drives exceptions where needed. Rochester is part of the Finger Lakes region, where the COVID positive test rate is just 0.7 percent. However, as much as things have improved in New York City, its positive rate is 1.1 percent. As a result, although the entire state is now technically in Phase 4, Governor Cuomo’s office cited the city’s current positive rates in announcing that indoor malls there would still remain closed until the situation improves.

For some mall owners and contractors, that may translate to more time to ensure that filters and systems can clear a newly raised COVID-era bar for safety, and that still might not be the end of it.

Brainbox AI’s Tabba pointed to a recent open letter in the New York Times from 239 experts.

“The evidence they cite is significant and implies that the virus can be spread via aerosolization and get recirculated via the HVAC system,” he said.

As opposed to transmission via droplets in a fairly established radio, aerosol-based transmission could represent a new degree of challenge for those managing and servicing indoor environments. For the moment, there seems little choice aside from working to reflect current guidance and waiting to see where new findings and larger U.S. trends in containing the disease might lead HVAC best practices.