Compressed Air Heat Recovery
Air compressor heat recovery can make a huge difference to lowering the carbon footprint and reducing energy consumption at a manufacturing site.
Like many socially responsible manufacturers, you may be looking for new ways of reducing your carbon emissions and energy consumption. Obvious steps like the use of low-energy light bulbs and automated heating offer some immediate carbon savings. However, even once these steps are taken, there remains a pressure to reduce further.
Statistics show that compressed air typically accounts for about 12% of the total energy costs for industrial manufacturers - for some facilities, the figure may reach as high as 40%. However, the good news is that between 70-94% of energy consumed by air compressors is recoverable. Without any form of recovery, this energy is lost through radiation to the atmosphere or through cooling systems.
This eBook identifies opportunities to recover waste heat from air compressors
Are heat recovery systems worth it? Do you have any examples at customer sites?
One example of a heat recovery system at a customer is a Midlands-based manufacturer making textiles for the automotive industry. Using an oil coolant in their ER-S5 energy recovery unit, they recover heat from an air compressor outlet. Hot oil from the air cooler transfers energy into the process via a steel plate heat exchanger. This gives them a continuous supply of hot process water without any extra energy purchase. As a result they were able to reduce CO2 emissions by 260,000 tonnes per year and save £37,000/year using this recovery method. A packaging plant in Northern Ireland found a different use for recovered energy. Greiner Packaging uses its excess heat to contribute to the central heating system of a local secondary school. Dungannon Integrated College has 600 pupils and uses £40,000 of heating on an annual basis. In this case, Atlas Copco installed Z-range oil-free screw compressors with water coolers for energy recovery. Up to 80% of the electrical input energy is recovered as hot water. The school also reduced its CO2 footprint by 200 metric tons through reduced energy purchase.
How much of the waste heat of compressors can be recovered?
To illustrate the vast untapped potential of compressed air heat recovery, it is calculated that heat recovery technology could save 1.99% of the total industrial electricity consumption in the UK. If that statistic isn’t compelling enough, it is the equivalent of removing the emissions from 913,000 diesel/petrol cars per year, or recovering the energy required to power 1.544 million households’ electricity consumption per year!
*Calculations are based on total industrial electricity consumption in the UK, and an average of 10% of industrial electricity consumption being used by compressors. (2021)
*Approximately 70% of energy is recoverable from oil-injected screw compressors, and up to 94% from oil-free water-cooled screw compressors.
How does a compressed air heat recovery system work?
Which air compressors offer heat recovery?
We estimate that 90% of all industrial air compressors used in the UK could be equipped with heat recovery systems, including most of Atlas Copco's oil-injected GA range, and our oil-free ZR & ZH compressors. Heat recovery/energy recovery functionality can come either factory-fitted as an option into your compressors or can be installed as a standlone unit.
How much energy can I save with heat recovery?
Use our energy savings estimator below to estimate how much waste heat you can reuse from your compressors.
If you need a more precise answer you can request a bespoke calculation from one of our heat recovery experts!
