Purging indoor pollutants requires an air change in 4-5 hours. ASHRAE suggest 7 cfm per occupant for non-smoking space. My take is that the one person in a space requires the space air change rate to purge indoor pollutants.
An example of 10,000 ft.^3 space requires 42 cfm of fresh air. Using the 7 cfm fresh air per person rule suggest that 1-6 occupants will get adequate fresh air. Additional occupants require an additional 7 cfm per occupant.
The fresh air requirement for homes is 7 cfm per design occupants plus 1 cfm per 100 sqft as a minimum.
It is also suggested that fresh air is not required when the space is unoccupied.
CO2 control is able to detect a single occupant in a 1,000 sqft space to activate the minimal .25 ach required to purge the indoor pollutants.
So, even one occupants should require a minimal air change rate to purge pollutants.
I am also curious about the real ASHRAE requirement.
Bear Rules: Keep our home <50% RH summer, controls mites/mold and very comfortable.
Provide 60-100 cfm of fresh air when occupied to purge indoor pollutants and keep window dry during cold weather. T-stat setup/setback +8 hrs. saves energy
Use +Merv 10 air filter. -Don't forget the "Golden Rule"