That should be ducts, haha. Seriously, my wife has been bugging me to get our AC ducts cleaned for sometime so I finally got around to it picking a cleaning company in the Houston area that charged about $250 to do this. Another company charged $450 so I went with the less expensive company- don't say anything. There was however a hitch- a couple of the ducts had mold on them and there was some mold in the same ducts. I asked how much to treat mold and the answer $499 to spray some stuff in the return duct and allow it to blow out through the AC system. I asked why it was so expensive and was told the chemicals were top notch, non-toxic to humans and because a 2 year warranty was offered. The name of the stuff was Mold Maximum Oder Treatment that looked and smelled like a detergent and did not say anything about it being a herbicide (mold remover), but it smelled good. Without proof, deep down I suspect this is a duct cleaning scam, but bottom line I don't know for sure. Anyone have any experience with this? I had not researched this in advance, not even thinking about mold, and was unsure of the effectiveness of this treatment but paid it. I have no clue if this company is performing an honest mold treatment service or they took some detergent and sprayed it in the ducts for $499 and a 2 year warranty. I have done some research and the word is that most houses have some mold in them in the AC duct. What is important is that you not allow it to get out of hand and to avoid the black toxic stuff, although there can be black mold that is not toxic. See this article. My experience cost me a total of $800. Most of my concern is regarding 10 minutes of spraying "something" into my return duct as a means of killing mold. From what I've read, duct cleaning which includes mold can range from $600-$2000.For anyone considering their ducts cleaned, and you live in a hot/humid climate, I suggest you give the company a grilling in advance regarding mold treatment, what chemical they use, what they charge, and check the BBB or Angie's list. I spoke with my brother who works in the building trades afterwards and he tells me companies frequently use scare tactics to get you to buy the mold treatment. Regardless, the bottom line is that mold should not be ignored.