Why Is My House So Dusty? Start at the Floor Register

Aaron, our duct cleaning technician, in a headlamp and respirator, kneels at a return in a living room, right beside a bookshelf. The return is the larger grille that pulls air back to the system. He feeds a red vacuum hose into the duct opening so the loose dust gets pulled out instead of stirred into the room.

Then the camera drops to a floor register, the supply grille where heated or cooled air comes out. Its louvers are caked gray. That's dust around air vents in its most obvious form, and it hints at what's sitting further down the duct.