A facilities manager at a building products plant attended a compressed air efficiency seminar sponsored by his local utility. He learned about optimizing air compressors, filters, dryers, and piping. He discovered how to arrange to have a baseline taken of his compressed air system to assess its efficiency. He discovered the excellent savings he could achieve if he reduced his leaks and changed his compressor control to variable speed mode. But the thing that really caught his attention was a bit he learned about heat recovery.
The biggest output of an air compressor, he discovered, was heat, and plenty of it. And heat was on his mind. It had been a mighty cold winter, and his maintenance workers were constantly complaining about the chilled working conditions they experienced in their drafty, poorly insulated old plant.
Basically, for every kilowatt an air compressor consumes, about the same amount of heat is expelled from the compressor cooling system — in this case, an air-cooled compressor. He was changing his compressor anyway, so he arranged to have the ventilation ducting modified so that waste compressor heat, previously blown outside in winter, was directed right to the area where his workers were complaining.
His staff were thrilled with the nice compressor heat blowing up their backs, just like a fireplace. He was thrilled because the compressor heat reduced his natural gas heating bill. And the power utility was happy too — so much so that they cut him a check to help pay for his new system. A win/win/win arrangement!