Sturtevant produced both Air Preheaters and Fuel Economizers.
The object of the Sturtevant Fuel Economizer was to extract the heat from the waste gases escaping up the chimney in boiler plants and using this to heat the feed water to a high temperature before it entered the boilers. The Air Preheaters operated on the same principle, raising the temperature of the air instead of water.
The feed water is contained in cast iron pipes, arranged vertically in rows and connected by top and bottom connecting headers. The whole apparatus was enclosed in a brick or metal asbestos casing.
Westinghouse ended this product line in 1945