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To calculate the required CFM for a room, you need to know the room's volume and the desired air changes per hour (ACH). The formula is:
CFM = (Room Volume in Cubic Feet × ACH) ÷ 60
Use the form above to input the room dimensions and ACH, and the calculator will provide the required CFM.
| Room | Recommended ACH |
|---|---|
| Living room | 3 – 4 |
| Bedroom | 5 – 6 |
| Kitchen | 7 – 8 |
| Bathroom | 7 – 8 |
| Laundry room | 8 – 9 |
| Attic (if cooling) | 12 – 15 |
| Garage (if used for work) | 20 – 30 |
| Area (sq ft) | Required Ventilation (CFM) |
|---|---|
| <500 | 30-60 |
| 500-1,000 | 45-75 |
| 1,000-1,500 | 60-90 |
| 1,500-2,000 | 75-105 |
| 2,000-2,500 | 90-120 |
| 2,500-3,000 | 105-135 |
| 3,000-3,500 | 120-150 |
| 3,500-4,000 | 135-165 |
| 4,000-4,500 | 150-180 |
| 4,500-5,000 | 165-195 |