(a) source means separately containing a first fluid and a second fluid;

(b) pressurizing means structured to separately pressurize the first and second fluids of the source means;

(c) injection means including a plurality of injectors spaced along and permanently affixed to the air distribution system, the spacing between adjacent injectors of the plurality of injectors being determined by the relative internal volume of the air distribution system being served by each respective injector of the plurality of injectors;

(d) a first distribution subsystem structured to convey the first fluid from the source means to the plurality of injectors;

(e) a second distribution subsystem structured to convey the second fluid from the source means to the plurality of injectors;

(f) control means structured to control the pressure and flow rate at which the first and second fluids are conveyed by the first and second distribution subsystems to the plurality of injectors; and

(g) a cleanup means structured to remove at least the first fluid from the air distribution system; and

(h) wherein each of the plurality of injectors is structured to receive and covert the first and second fluids into a foam-like substance and to inject the foam-like substance into the air distribution system until ductwork thereof is completely filled and wherein the cleanup means is structured to subsequently remove at least the first fluid without exposure thereof to the atmosphere.