The reasoning I've heard is that greenhouses provide group isolation rather than overall ventilation per se, but there's usually also a trapdoor or partially open roof to vent the air, so it does work in some sense. This is what it looks like in practice in Chicago [0].
Indoor Plexiglass partitions provide isolation too but the level of isolation is more limited. Plus the air in a smaller indoor location is recirculated between partitions, whereas outdoors it is ostensibly exchanged at much higher rates.
Which makes me wonder, can't we build indoor booths?
The catch would be one would also need a HVAC that can exchange air outside the booths at high throughputs like aircraft cabins.
ACPH = air changes per hour = 60 * Q / L where Q = volumetric flow (ft3/min), L = ft3.
Aircraft cabin ACPH are around 20-30 (and through a HEPA filter) [1], while a restaurant dining area is 8-12 [2] (many assumptions here, like airtightness, etc), and no HEPA.
Indoor Plexiglass partitions provide isolation too but the level of isolation is more limited. Plus the air in a smaller indoor location is recirculated between partitions, whereas outdoors it is ostensibly exchanged at much higher rates.
Which makes me wonder, can't we build indoor booths?
The catch would be one would also need a HVAC that can exchange air outside the booths at high throughputs like aircraft cabins.
ACPH = air changes per hour = 60 * Q / L where Q = volumetric flow (ft3/min), L = ft3.
Aircraft cabin ACPH are around 20-30 (and through a HEPA filter) [1], while a restaurant dining area is 8-12 [2] (many assumptions here, like airtightness, etc), and no HEPA.
[0] https://www.timeout.com/chicago/news/dine-and-drink-in-a-pri...
[1] https://www.iata.org/contentassets/f1163430bba94512a583eb6d6...
[2] https://www.engineeringtoolbox.com/air-change-rate-room-d_86...