Most of the electrical energy used by an industrial air compressor is converted into heat and has to be conducted outwards. In many cases, a properly designed heat recovery unit can recover a high percentage of this available thermal energy and put to useful work heating either air or water when there is a demand.
Heat recovery systems are available for most compressors on the market as optional equipment, either integrated in the compressor package or as an external solution. An existing CAS can generally be retrofitted very easily and economically. Heat recovery systems are applicable for both air- and water-cooled compressors.
As much as 80 - 95 % of the electrical energy used by an industrial air compressor is converted into thermal energy. In many cases, a properly designed heat recovery unit can recover approximately 50 - 90 % of this available thermal energy and put it into useful work heating air or water.
The potential energy savings are de pendent on the compressed air system, on the operating conditions and on the utilisation.
Recoverable heat from a compressed air system is normally insufficient to be used to produce steam directly.
Typical air temperatures of 25 to 40 °C above the cooling air inlet temperature and water temperatures of 50 to 75 °C can be obtained.
Energy Efficiency (2009) 3.7.5