Air compressors do more than just provide compressed air. They can also be used as a source of heat - helping businesses save on energy costs and reduce their carbon footprints in the process.
Due to the steep and rapid increase in energy costs, today’s manufacturing and business environments need to employ smart energy cost reduction strategies in order to remain competitive. On top of this, there is an increasing need for businesses to meet sustainability targets, and reduce their carbon footprint. Manufacturing plants and other facilities are doing whatever they can to streamline their operations and improve efficiencies.
This means facility engineers are tasked with optimising the energy efficiency of their operations, and extracting as much productivity out of every unit of energy paid for and consumed, as possible.
Compressed air as an energy source
Historically, compressed air systems have been a major component of industrial energy consumption with energy consumption also representing the majority of a compressor’s total life cycle cost.
However, compressors also generate heat, which must be removed to maintain proper compressor operating temperatures and cool the compressed air to make it useable. It’s this heat that can be harnessed for other uses.
While 100% of the electrical energy used by industrial air compressors is converted into heat, it is mostly lost to the ambient environment through the compressor’s cooling system. However, 96% of this heat can be recovered and put to good use reducing a facility’s energy cost.
Heat recovery applications
Capturing warm air from compressors can be as simple as integrating standard HVAC ductwork, controls and, optionally, supplemental fan to eliminate back pressure. These measures will allow warm air to be used as heating within the building, which can be easily regulated with the use of thermostatically controlled, motorised louvre flaps allowing partial or full flow of the heated air.
Rejected heat can also be used to heat water or other fluids. While water-cooled compressors offer the best efficiencies for this type of heat recovery, discharging water at temperatures reaching 71°C, air-cooled units can also be used. The water can be connected to a continuous process heating application, such as a boiler’s return circuit.
Another application comes in the form of plate-type heat exchangers, which allow the capture of heat for diverse processes such as electroplating, chemical processing, and laundry services. Fail-safe heat exchangers ensure the fluid being warmed is protected from contamination by the coolant and is suitable for the food, chemical and pharmaceutical industries as well as for heating potable water for cafeterias and restrooms.
The multiple benefits of heat recovery
Heat recovery is about more than just utilising rejected heat for other applications. Removing the heat of compression will make compressor room temperatures more bearable for those who work there while maintaining proper ambient conditions will also improve compressor efficiency and facilitate air treatment. Moreover, controlling operating temperatures will extend compressor air equipment life, all of which saves money.
And thanks to the savings on energy usage, there are also benefits to the environment as heat recovery reduces the carbon footprint of a plant. As energy policies and regulations continue to evolve, these considerations are only expected to become more important.
Go yellow. Be green. Save money.
Get in touch for consulting and analysis expertise from an HPC KAESER specialist about optimising your current compressed air system, or to discuss a new system, to optimise heat recovery for your requirements.
HPC KAESER offers a range of products, including blowers and rotary screw compressors supported by experienced and knowledgeable HPC trained engineers and a nationwide network of authorised distribution partners. Contact us to find out more.