Patent ID: 7617829

Claim:
A method for cleaning the ductwork of an air distribution system having inlets and outlets, the method comprising the steps of: (a) permanently affixing a plurality of injectors along the ductwork wherein: (1) each injector includes a mixing chamber with a distal end opening directly into the ductwork, and (2) the spacing between adjacent injectors is determined by the internal volume of the ductwork being served by each respective injector; (b) permanently connecting first and second distribution subsystems in flow communication with each of the mixing chambers; (c) blocking the inlets and outlets of the ductwork; (d) connecting: (1) a first source containing a first fluid to the first distribution subsystem, and (2) a second source containing a second fluid to the second distribution subsystem; (e) pressurizing the first and second fluids in the first and second distribution subsystems; (f) controlling pressurization of the first and second fluids in the first and second distribution systems causing: (1) the first and second fluids to be converted into a foam-like substance in the mixing chambers, and (2) the foam-like substance to be injected into the ductwork; (g) continuing conversion of the first and second fluids into the foam-like substance and injecting the foam-like substance into the ductwork until the ductwork is substantially simultaneously completely filled with the foam-like substance wherein all contaminants and debris in, and on internal surfaces of, the ductwork are absorbed and entrapped by the foam-like substance; and (h) subsequently removing: (1) the blocking of the inlets and outlets of the ductwork, and (2) the foam-like substance from the ductwork.