Acceptable indoor air quality and required make up air.
The purpose of ASHRAE 62 - Ventilation for Acceptable Indoor Air Quality standard is to specify minimum ventilation rate and indoor air quality acceptable to human occupants with intention to minimize the potential for adverse health effects.
ASHRAE 62 recommended minimum Outdoor Air Flow
Range 15 - 60 cfm per person
Most common range 15 - 35 cfm per person
Average range 15 - 20 cfm per person
ASHRAE 62 recommended maximum CO2 Concentration
Outdoor background level 350 ppm CO2 in the air
ASHRAE recommend less than 1.000 ppm CO2 in the air
Human discomfort begins at levels above 800 - 1.000 ppm CO2 in the air
Long term health effects for concentrations above 12.000 ppm CO2 in the air