Air Changes per Hour Method
Calculate CFM based on room volume and required air changes
Room Volume
3,000 ft³
Required CFM
300 CFM
CFM per sq ft
1.0 CFM/ft²
ASHRAE 62.1 Ventilation Rate Procedure
Calculate outdoor air based on people and area components
People Component (Rp × Pz)
100 CFM
Area Component (Ra × Az)
60 CFM
Total Outdoor Air (Vbz)
160 CFM
CFM per Person
8 CFM/person
Exhaust Air Requirements
Calculate exhaust CFM for restrooms, kitchens, and labs
Total Exhaust CFM
200 CFM
Minimum Makeup Air (80%)
160 CFM
Makeup Air Calculation
Calculate makeup air for exhaust systems
Target Makeup Ratio
100%
Net Makeup Required
2,000 CFM
Makeup Air Unit Size
2,000 CFM