Before: Photos document loose debris and attached dust on the floor and walls of the return cavity, plus deposits near the flexible duct opening. Process: We opened the return for access and connected vacuum collection under negative suction. The photos document the collection hose, floor protection, and agitation equipment used for source removal. After: Comparison photos show exposed return-cavity surfaces and flexible duct lining after cleaning. Existing dark coloration and adhered surface marks remain distinct from loose dust and debris removed during service.