When New York City reopens for indoor dining at 25 percent capacity starting today, diners will see plenty of hand sanitizer, masks, gloves, and plastic partitions to keep them safe from the coronavirus. But there will also be expensive technology that they won’t see, working behind the scenes to combat an invisible threat.
It is widely accepted at this point that COVID-19 is transmitted via droplets and aerosols that cannot be seen by the human eye, thanks mostly to an early report on indoor transmission that is the stuff of restaurant owners’ nightmares. A guest, infected with the coronavirus, sat in the line of fire of an air conditioner at a restaurant in Guangzhou, China. As the virus particles swirled through the air, nine more people were infected. Five of those people were sitting at other tables.
This case study, published in early April by the Centers for Disease Control and Prevention, has become one of the most publicized reports about indoor dining during the pandemic. It is constantly shared, including by New Jersey Gov. Phil Murphy in August, as irrefutable evidence that indoor dining is dangerous.
But the report was preliminary, and a deeper dive into the incident showed that while the virus spread to the nine other guests in the restaurant by droplet and likely aerosol transmission, the culprit was, in fact, a very archaic air-conditioning unit that operated more like a fan, blowing the virus around without bringing in any fresh air.
“This restaurant didn’t have any mechanical ventilation,” says William Bahnfleth, professor of engineering at Penn State University, who focuses on HVAC (heating, ventilation, and air conditioning), thermal storage, and indoor air quality in his research. “So the only way that outdoor air was getting into it was by leakage. There was a toilet exhaust fan running and that was about it.”
New York City restaurants will be relying on much more upscale technology than a toilet exhaust fan to keep their customers safe.
For the past several days, Top Line Hospitality Services owner Scott Bankey has been running around Lower Manhattan, upgrading restaurants’ HVAC units to MERV-13, a rating system for filtration that ranges from window A/C units at 1, up to a max of 20. Hospitals, for context, operate at MERV-15. The air exchange rate of a modern HVAC system alone is several times greater than the unit from the Guangzhou case study.
But on the roof of the Michelin-starred Musket Room in Soho, Bankey installed a bit more: ultraviolet lamps designed to inactivate up to 99 percent of funguses, bacteria, and viruses in the air that’s been vented from the restaurant. The sanitized air then hits the filter, is mixed with fresh air, and is pumped back inside.
Musket Room staff were at first anxious about serving unmasked customers indoors, but owner Jennifer Vitagliano reviewed the additional modifications with them so that they could research it for themselves. “Everyone feels really confident that we’re going above and beyond to create a safe environment,” says Vitagliano, who would not confirm the exact price of the modifications but said that it cost the restaurant “a few thousand dollars.”
“There’s a very good track record for UV, because it’s been used in infection control since at least the 1930s,” says Bahnfleth, who also serves as the chair of the epidemic task force for ASHRAE (American Society of Heating, Refrigerating and Air Conditioning Engineers). “It wasn’t something that most people were aware of, but it’s been around for a long time. I’ve been doing research on it for over 20 years.”
Le Bernardin, the only three-Michelin-starred restaurant to reopen September 30 — the first day indoor dining is allowed again in NYC — advertises on its Resy page that it has installed a Needlepoint Bi-Polar Ionization system, which they say is “proven to eradicate 99.4% of airborne COVID-19 particles within 30 minutes.” The technology sounds like the stuff of science fiction: Charged particles are released into the air to hunt for dust and viruses, deactivating them upon contact. While UV lamps rely on air that’s been sucked into the HVAC unit to be sanitized, bi-polar ionization systems are, in theory, proactive. Their efficacy is still up for debate, since there have been few peer-reviewed studies on the technology.
“What ionizers definitely do is charge particles so that they stick together and they can be removed from the air more efficiently,” says Bahnfleth. “Like UV, ionizers have been around under the radar for quite a while, but they’re just something everyone’s aware of now because of the pandemic. They weren’t invented yesterday.”
The cost of these units is high, especially for restaurants that are already financially strapped as a result of the pandemic. The team at Crown Shy in the Financial District is operating at just 10 percent of their pre-pandemic revenue, but spent $40,000 adding a bi-polar ionization system to the HVAC units that service both the ground-floor restaurant and its soon-to-open restaurant in the sky, Saga.
“It’s expensive, but it’s worthwhile,” says general manager and partner Jeff Katz. “Our first concern is making people feel comfortable in the space, so that they can think as little as possible about the global pandemic. Nothing ruins a meal like the thought of pathogens.”
AtmosAir, which manufactures the units that were installed in Crown Shy, has seen its revenues rocket to five to six times what it was at this point last year. “Demand is very high in New York City,” says Brian Levine, AtmosAir’s vice president of marketing.
Coronavirus preparation, like most other things, is a battle between the haves and have nots. Smaller neighborhood joints are more likely to just buy HEPA air filter units for several hundred dollars. But an organization like Union Square Hospitality Group, which operates restaurants like Gramercy Tavern, Blue Smoke, and Union Square Cafe, can afford to leave no box unchecked, spending tens of thousands of dollars to beef up its filtration systems, adding both a UV light rig and bi-polar ionizer at each of its locations.
While these extra precautions may be helpful to ease the minds of a shell-shocked population, the state reopening guidelines also recommends simple things like a basic ventilation system or even leaving all the doors and windows open. Restaurants in the Northeast and the rest of New York State have been open for indoor dining for months without a surge in coronavirus cases, despite many places lacking the resources to install high-end HVAC systems.
In recent interviews, the nation’s leading infectious disease expert, Dr. Anthony Fauci, stated that dining indoors “absolutely increases the risk,” but stressed the importance of harm reduction in dealing with COVID-19. “There comes a point where you’ve got to accept human nature,” Fauci said of people’s desire to socialize. He added that in addition to a low local positivity rate, “anything that has airflow out, not airflow in the room” was the key to making restaurants safer.
“There’s a lot of evidence that good ventilation is protective,” says Bahnfleth. “And when you add filters to it and air cleaners, things get even better.”