I brought these guys in a few years back because they are listed on Mike Holmes site as reliable duct cleaners. I paid a fortune because I thought they were professionals since Holmes listed them. 2 years later I had to get it done again because my filters were dirty and neeeded to be replaced every couple of months. When another company came in this week, they showed me that my return ducts were filthy and NEVER cleaned. i.e. since no access holes were cut in the return ducts, how could they have been cleaned? I would NOT recommend OPADC. I am out close to $500 with little to show for it. There are better companies listed on Homestars that you should use. What does Holmes always say, "Do it right the first time"? Not these guys.