Programs that provide labor and/or supplies for people who need to have the air ducts for their heating and cooling system cleaned to improve the quality of their indoor air. Duct cleaning generally involves the cleaning of various heating and cooling system components of forced air systems including the supply and return air ducts and registers, grilles and diffusers, heat exchangers, heating and cooling coils, condensate drain pans (drip pans), fan motor and fan housing, and the air handling unit housing. Cleaning is recommended if there is visible mold on surfaces within the system, an infestation of vermin (rodents or insects), or ducts are clogged with excessive amounts of dust and debris.