Estimate supply flow in litres per second and cubic feet per minute from air changes and room volume.
| Flow (L/s) | – |
| Flow (CFM) | – |
Use this calculator when a brief asks for ACH and you need the fan flow. Enter air changes per hour and the room volume in cubic metres.
Flow (m³/s) = ACH × volume ÷ 3600. L/s = that flow × 1000. CFM = L/s ÷ 0.47194745. Volume stays in m³. CFM is a parallel display, not a converted L/s picker.
This is a well-mixed-room conversion. It does not size ducts or a filter.
ACH: Target air changes per hour.
Volume (m³): Room volume in cubic metres.
Flow (L/s): Supply flow in litres per second.
Flow (CFM): Same flow in cubic feet per minute.
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