Abstract: A cleaning system utilizes heat from an internal combustion engine to heat cleaning liquid which is sprayed onto a surface to be cleaned. The internal combustion engine drives a vacuum pump which withdraws air and cleaning liquid through a vacuum nozzle for retrieving cleaning liquid and soil. The heated air leaving a vacuum pump is combined with heated exhaust gasses from said engine and heat from the mixture is extracted to heat the cleaning liquid. The cleaning liquid may be further heated by heat extracted from the engine by a cooling system.

Abstract: Multiple side-by-side vacuum nozzles are reciprocated along paths of travel parallel to the preferred path of travel of carpet cleaning apparatus. The vacuum nozzles are propelled through a drive mechanism which moves each vacuum nozzle out of phase with the movement of every other nozzle. Cleaning fluid discharge members associated and movable with each vacuum nozzle direct cleaning fluid onto the carpet adjacent their respective vacuum nozzles.

Abstract: A cleaning system includes a liquid heating system utilizing heat from the cooling air and the exhaust gases of an internal combustion engine. A heat pump driven by the engine is utilized to extract heat from the cooling air and impart that heat to a first heat exchanger. A second heat exchanger is associated with the exhaust gases for extracting heat therefrom. Liquid to be heated is conveyed through said first and second heat exchangers.