In May, I bought an older home in which the previous owners smoked heavily. They also had dogs. We had the carpets cleaned by another company but I still noticed the distinctive odors of cigarette smoke and stinky dog whenever the air conditioner was running. I had Kelly's come out in June to clean the air ducts and what a difference! They did a fantastic job cleaning years of smoke and dust and dog hair out of the vents. They were timely, professional and friendly. The cost for what they did was very reasonable.