We live in a completely redone home with the original part of the house dating back to 1905. We have no idea if/when the ducts have ever been cleaned. The before and after photos were amazing, as were the items that came out of the ducts. We are only the fourth owner, and we know about when the central hear went in. We could guess from the child's drawings, the balls, the coins, etc. the dates. Then there was the dirt, the dust and the rest of what came out! They did a great job. They were clean when they arrived, filthy when they left and worked for several hours nonstop. Well worth what we paid. Highly recommend this service. We had this done previously in another house, and this company was thorough, professional and willing to answer questions.