I don't believe the air duct cleaner guy cleaned the system thoroughly. The first day he came, he didn't clean because he said, he had the wrong equipment as my house requires a different equipment. The next time he came, he said he cleaned downstairs but I he didn't because he left without turning the vacuum/machine. Anyway, he suctioned the one in living room and the hallway hall, but it was only two ducts he cleaned. 10 mins top he was out, that included bringing the vacuum and turned on for one minuted and left. But he was respectful.