Harnessing Wasted Heat from Air Compressors for Significant Energy Savings  

Countless companies in the industrial sector use compressed air daily. It’s crucial in the manufacturing process, but did you know that compressed air systems are a notorious source of wasted energy? A large chunk of energy used in the compression process is lost as heat. The good news is that there are new, innovative solutions that can harness that wasted heat from air compressors while cutting costs and contributing to sustainability initiatives.   

Lost Energy During Air Compression 

In some manufacturing plants, compressed air systems account for around 12% of the total energy cost; sometimes, it goes up to 40%. It’s often overlooked that up to 94% of the energy supplied to the air compressor is converted into heat, which is then lost into the atmosphere. This wastage increases bills and energy consumption. However, this doesn’t have to be the case. Up to 90% of industrial compressors in the UK could utilise waste recovery systems, showing a lot of untapped potential.  

What is Compressor Waste Heat Recovery? 

The large amount of lost energy that dissipates into the atmosphere through heat can be recovered by capturing it during the compression process. The heat, which is a natural byproduct of the process, can be harnessed to cut down energy usage and operating costs. In air-cooled systems, the warmed air can be used to heat buildings, which is especially useful in the winter months.  

Simple modifications like ducting and fans can redirect the recovered heat to other uses. Adequate heat recovery depends on some factors such as a stable energy demand, and insulating ductwork or relocating compressors can maximise efficiency. This approach reduces operational costs and environmental impact. 

How Much Energy Can You Save? 

A significant amount of energy can be saved when heat is recovered during the compression process. In many cases, the heat recovery can exceed 90% if the energy that’s gained can be effectively utilised. This can depend on factors, such as the function of the cooling system and the distance to the point of consumption. The payback period for heat recovery units is generally short, varying from 1 to 3 years. 

Uses for the Recovered Heat 

The hot water that’s recovered can be utilised in numerous industrial processes, including the following: 

• Food and Beverage: Pasteurisation, scalding, cleaning, sterilising, and drying cooking vessels. 

• Chemicals: Thermal steam crackers, re-boilers, stripping, heat tracing, and humidity control. 

• Pharmaceuticals: Fermentation temperature control, drying, and sterilisation processes. 

• Textiles: Fabric colouring and yarn treatment. 

• Pulp & Paper: Bleaching, digesters, pulp machines, and black liquor evaporators. 

• Electronics: Humidity control in assembly and chip manufacturing. 

• Motive Applications: Steam turbines. 

Return on Investment (ROI) 

Installing an energy recovery system can lead to considerable financial benefits. For example, a central compressor plant consuming 500 kW over 8,000 operating hours per year can consume 4 million kWh annually, in this case the potential to recover up to 94% of this energy as usable heat provides an opportunity to make a significant return on the initial investment. Energy recovery processes can also enhance the air compressor’s performance, reliability, and longevity by preserving its optimal operating conditions.  

Better For the Environment  

Heat waste recovery can be implemented as a sustainability initiative since an air compressor’s typical carbon footprint accounts for 99% of its CO2 emissions. By implementing heat recovery systems, industries can significantly reduce their carbon emissions and contribute to a better future for the planet.  

Recovering wasted heat in the air compression process offers industries an opportunity to reduce energy consumption, cut costs, and lower carbon emissions. Contact our experts at Airia to find out more about how this new technology can help you.