When constructing a home office, I tried to calculate the ventilation-airflow requirements to keep the office CO2 below problematic levels. IIRC, I assumed two

When constructing a home office, I tried to calculate the ventilation-airflow requirements to keep the office CO2 below problematic levels. IIRC, I assumed two persons occupying a 1200 ft^3 space, with replacement air coming from the rest of my house. I'm not sure my math was correct, but the required airflow rate was surprisingly high, maybe in the ballpark of 100 cfm? Well above the ASHRAE 62-89 recommendation of >= 20 cfm/person.