HVAC · Room airflow arithmetic
Compare room airflow in CFM.
Apply your own ACH and per-person airflow criteria, then see both bases and an equal-outlet planning split.
← Room length →↕ Room height↕ Room widthRectangular room volume
← Planning airflow →↕ Supply outlet countEntered ACH · entered people rate
1 Measure the room
2 Enter planning criteria
Transparent calculation
Volume CFM = length × width × height × entered ACH ÷ 60.
The occupancy comparison multiplies whole occupants by your entered CFM per person. The headline displays the larger arithmetic result without claiming that either criterion is suitable.