Before I forget, I had an Aranet #CO2 monitor with me the entirety of #CFASummit. Hallways and main stage was 800-1000, breakout rooms were 1000-1200. Given how crowded it was there, not bad!
(450 is outside, 500-700 inside is amaze level of ventilation, the worst reading I’ve seen is 4500+ inside a car with 3 people with AC blasting and recirculating. 😅)