How long can you stay in a 50-ft dome if you shut off the air exchange during wildfire smoke?

Quick question for the group:

A 50’ × 17.5’ ellipsoid dome has a known internal cubic volume (calculator link: Ellipsoid Dome Calculator - Monolithic Dome Institute ). But what I’m trying to figure out is how much of that is actually breathable air, and how long could two adults stay inside if the air exchange system had to be shut down—say, during wildfire smoke?

Anyone with experience in ventilation math, CO₂ load, or sealed-enclosure modeling—your insight would be great.

I thought about this after posting. My wife and I have a CO2 meter that a workshop attendee got me interested in. We love it. Battery lasts a long time, and it data logs! Very cool

https://www.amazon.com/Aranet4-Home-Temperature-Ink-Configuration/dp/B07YY7BH2W/ref=sr_1_4_pp?crid=3CJFXUWYCXYQZ&dib=eyJ2IjoiMSJ9.XY4AeSfPlzOfB1JL87gN1Mfd8id1ieTKlDovgWhUQsagWJDt9Ko3ldP30PaDRPZ_yNe1dz_W1QkVdRtOT-rtT7zTZkCnGP4KM0dcDxWQIq4h15sl03exJKIhX7wC4ouHoF1VFWW4HJV2bLP80TKevyovq1caO3X8ew1xP7sZmJ8hC6Lv1Q9-1V_RAGGX54OHzRdQQ5lPC3UNDRhGNbqxFu_Z2n1zdYC2FoYpQS0jGo4.k7yb-KPNShoVXYIQbXVpRZ8d4zFgCIXye8tDUlejlnA&dib_tag=se&keywords=co2+meter&qid=1763994094&sprefix=co2+meter%2Caps%2C162&sr=8-4

Couldn’t vent tubes have filters on them that would filter out at least a large part of the smoke particles?

Or could a generator be used solely to power a really great air filter (venting the generator out of the dome, of course)?

I would think you could fab a water bubble or filtration, like they used in a paint booth..?

@Mike

Now, come on, that monitor is “Made in the European Union."

It is just as easy to search on Amazon and find something made in the USA. Here’s an example to search for:

Indoor Air Quality Monitor Made In Usa