Only about 10–20% of the electrical energy input to an air compressor is converted into useful work for air compression, while 80–90% is transformed into heat and dissipated through various components. More than half of this waste heat can be effectively recovered.
For large-scale air compressors, a water circulation system can be used to capture the waste heat. The recovered hot water can then be reused for process preheating, cooling, or upgraded via heat pumps for further utilization.
Below is a reference chart showing the heat dissipation distribution across components for screw-type and centrifugal air compressors.
| Component | Screw-Type Compressor | Centrifugal Compressor | Remarks |
| Main Motor Cooling | 5%–10% | 5%–10% | Not recoverable |
| Oil Cooler | 30%–40% | 10%–15% | Heat can be recovered |
| Aftercooler | 30%–40% | 20%–30% | Outlet temp. for single-stage: ~120–200 °C; multi-stage: ~120–150 °C; heat can be recovered |
| Intercooler | N/A | 30%–40% | |
| Other Losses | 5%–10% | 5%–10% | Mechanical loss, casing heat dissipation, not recoverable |
For large air compressors or blowers, additional energy savings can be achieved through inlet air cooling. By pre-cooling the intake air, the system can operate more efficiently with the following benefits:
- Reduced energy consumption
- Increased air output (flow rate)
- Lower maintenance costs