CFM = room volume × air changes per hour ÷ 60.
Enter realistic numbers from the property, equipment, job record, or company reports. Small input changes can produce large differences, so compare the estimate with actual performance.
Practical answers
What is CFM in HVAC?
CFM means cubic feet per minute. It describes the volume of air moving through a space or duct each minute.
How is room airflow estimated from ACH?
Multiply the room volume in cubic feet by the target air changes per hour, then divide by 60 minutes.
Is this a substitute for system design?
No. Final HVAC design should account for heat gain, heat loss, equipment capacity, duct design, pressure, ventilation standards, and applicable codes.