My conversation with Douglas Mass was reassuring, too. Mr. Mass, a mechanical engineer and the president of the engineering firm Cosentini Associates, A Tetra Tech Company, has designed airflow systems that were regarded in the field as technical marvels. Yet as an advising member of a restaurant-safety panel convened by the Food & Society Program of the Aspen Institute, he has been advocating some extremely low-tech solutions to lower the risk of indoor dining.
Placing movable partitions between tables, which New York State requires when tables cannot be spaced six feet apart, can help block some of the airborne particles sent flying by a sneezer or loud talker, Mr. Mass said. Opening a window or door will let in fresh air. Yes, in an ideal world a restaurant’s ventilation system would already do that, but the hospitality business is not an ideal world.
If uncontaminated air can’t be brought in from outside, it can be “mimicked,” Mr. Mass said, by filtering the contaminants out of indoor air. Mr. Mass advises restaurants to have their ventilation systems, many of which have been idle for half the year, thoroughly cleaned and then fitted with high-efficiency filters, such as MERV-13 or better. If those systems are too old or weak, he recommends buying free-standing air purifiers using HEPA filters, which can catch airborne particles carrying coronavirus. Some simple models sell for less than $200.
Mr. Mass, who lives in Manhattan, said a restaurant that follows best practices for safety and has good ventilation and widely spaced tables — separated, perhaps, by partitions — is one where he would consider eating in the coming weeks.
“I’m going to be the first one running out to restaurants when they open,” he said. “I’m comfortable. A lot of the restaurants are taking this very seriously.”
Just as Mr. Mass helped me think about indoor air, the architect David Rockwell changed my thinking about indoor space and how it’s used. All summer, the first encounter between diner and server — the one where you ask if they have a table and they say, just a minute, I’ll check — usually took place outside, on the sidewalk. What if it stays there in the fall and winter?