The Coronavirus and the Future of Restaurants

CC BY 2.0. Almost empty restaurant in Beijing/ Lloyd Alter

In those parts of China where the lockdown has been lifted, restaurants are open again, but nobody is going to them; everybody is still worried and fearful of infection. They may well have good reason to be worried; a new study of an early outbreak in a restaurant in Guangzhou shows that the virus was not transmitted by contact but through the ventilation system.

As noted in a recent post, it was previously thought that ventilation was not a big part of the problem; the thinking was that "air is not the vector by which the virus spreads." But that thought is changing fast, and has big implications.

The Guangzhou Case Study

According to the study, COVID-19 Outbreak Associated with Air Conditioning in Restaurant, Guangzhou, China, 2020, a family traveled from Wuhan to Guangzhou before the lockdown and had lunch on the third floor of a five-story windowless restaurant in Guangzhou on January 23. There were 91 people in the restaurant, and ten became ill. This was early enough in the pandemic that the researchers could identify and check all the diners, and were pretty confident that nobody else in the restaurant was carrying the virus.

Table layout in restaurant in Guangzhou, china

Lu J, Gu J, Li K, Xu C, Su W, Lai Z, et al. COVID-19 outbreak associated with air conditioning in restaurant, Guangzhou, China, 2020./CC BY 2.0

The carrier from Wuhan, a woman labeled A1 on Table A, could have contaminated everyone at her table by sharing food, as is common in Chinese restaurants. But the people eating at tables B and C are too far away for that, or so it was thought.

Virus transmission in this outbreak cannot be explained by droplet transmission alone. Larger respiratory droplets (>5 μm) remain in the air for only a short time and travel only short distances, generally <1 m (2,3). The distances between patient A1 and persons at other tables, especially those at table C, were all >1 m. However, strong airflow from the air conditioner could have propagated droplets from table C to table A, then to table B, and then back to table C.

So basically, the air conditioner beside table C blew air, and the virus, across all three tables, with it somehow bouncing back to table C, all a distance way beyond 2 meters or roughly six feet, which is how far big droplets travel. However, smaller droplets have been found to travel farther (as we noted in the previous post about HVAC systems), so the researchers have concluded that the aerosols followed the airflow.

We conclude that in this outbreak, droplet transmission was prompted by air-conditioned ventilation. The key factor for infection was the direction of the airflow.

Preventing the Spread of COVID-19 in Restaurants

To prevent spread of COVID-19 in restaurants, we recommend strengthening temperature-monitoring surveillance, increasing the distance between tables, and improving ventilation.

No big deal at all, right?

Retail and marketing consultant Piers Fawkes notes that patios will be a big deal this year, but then throws in, "Inside AC units will need to be all swapped out for systems that don’t spread infections." Do we even know what kind of AC unit that is? Do we know if it is airflow just blowing the virus around the room or is it actually being circulated in the system through ductwork? It's not so easy to re-engineer every restaurant's ventilation system.

Cano restaurant

Restaurant in Toronto/ Lloyd Alter/CC BY 2.0

What happens in the neighborhood restaurant, where they put so much money into building it, and your customers are sitting there wondering what's blowing out of the sides of that big duct? It's not going to be easy at all.

Restaurant patio in vancouver

Restaurant patio in Vancouver/ Lloyd Alter/CC BY 1.0

I suspect that Piers Fawkes is right about patios coming back first, but even there, nobody is going to want to sit too close.

Fancy restaurant in Porto, Portugal

Restaurant in Porto, Portugal/ Lloyd Alter/CC BY 2.0

Traditional formal restaurants with tablecloths and full plated service will let the wealthy sit far apart. Private dining rooms may even make a comeback.

Dinner in Beijing Restaurant

Dinner in Beijing/ Lloyd Alter/CC BY 2.0

The way we eat in restaurants may change; people are going to want plated food. Family style dining will probably be the last to come back.

Bar in Toronto

Bar in Toronto/ Lloyd Alter/CC BY 2.0

But the local restaurant and bar, even if it has been around for 35 years, may not reopen after this. They probably can't afford to take out any tables, and they certainly can't afford to change their mechanical systems. These are the places that we will probably lose, the places that give our neighborhoods their charm and character. They are what Michael Hickey called the "third space." Kaid Benfield described their green virtues:

What does this have to do with sustainability? Well, quite a bit, in my opinion. The more complete our neighborhoods, the less we have to travel to seek out goods, services and amenities. The less we have to travel, the more we can reduce emissions. People enjoy hanging out in bars and, especially if they are within walking distance of homes, we can also reduce the very serious risks that can accompany drinking and driving.

Demolition man

Taco bell in Demolition Man/Video screen capture

Instead, I suspect we will be like Sandra Bullock in Demolition Man, with every restaurant being a Taco Bell or some equivalent corporate restaurant; it will be new, it will be clean, it will be expensive and it will not be in your neighborhood. That may well be the restaurant scene after the coronavirus.