Fan Energy Saving Calculator
Estimate energy and cost savings when a fan is speed-controlled with a VFD/inverter.
Selected Speed Summary
Power at 100% speed
2.20 kW
Power at selected speed
0.93 kW
Energy saved
57.8%
Money saved per hour
£0.34
| Period | Cost at 100% | Cost at Selected Speed | Saving |
|---|---|---|---|
| 1 Hour | £0.59 | £0.25 | £0.34 |
| 8 Hours | £4.75 | £2.00 | £2.75 |
| 12 Hours | £7.13 | £3.01 | £4.12 |
| 1 Day | £14.26 | £6.01 | £8.24 |
| 1 Week | £49.90 | £21.05 | £28.85 |
| 1 Month | £216.05 | £91.15 | £124.90 |
| 1 Year | £2594.59 | £1094.59 | £1500.00 |
Assumption: this calculator is intended for centrifugal/axial fans controlled properly by a VFD/inverter.
Real-world results vary with motor efficiency, system resistance, operating point, and control method.
Quick Comparison Table
| Fan Speed | Approx. Power Draw | Energy Reduction vs 100% | Cost per Hour | Saving per Hour |
|---|---|---|---|---|
| 100% | 2.20 kW | 0.0% | £0.59 | £0.00 |
| 90% | 1.60 kW | 27.1% | £0.43 | £0.16 |
| 80% | 1.13 kW | 48.8% | £0.30 | £0.29 |
| 70% | 0.75 kW | 65.7% | £0.20 | £0.39 |
| 60% | 0.48 kW | 78.4% | £0.13 | £0.47 |
| 50% | 0.28 kW | 87.5% | £0.07 | £0.52 |
| 40% | 0.14 kW | 93.6% | £0.04 | £0.56 |
| 30% | 0.06 kW | 97.3% | £0.02 | £0.58 |