While some have discussed the benefits, or lack of for having your ducts cleaned, no one answered your question. I too am in the duct cleaning business. My customers often come back to me after cleaning, unsolicited, and tell me how much a difference it has made in their home and in their life to breathe better air in their home. That said, (not knowing where you live), you can find qualified duct cleaners at http://www.nadca.com, put in your zip, and those who are certified will come up in your area. Or, you can check out http://www.ductz.com for a very qualified DUCTZ professional who services your area (there’s a map and zip finder there too). You will want to find a certified, quality duct cleaner, and stay away from the “too good to be true price” coupon guys…It will typically cost between $500 to $1000, and take 5 to 7 hours to complete a typical one-system home, cleaning the ducts, trunks, pans, internal evaporation coils, blowers etc (All air stream surfaces need to be cleaned to get the benefits). If you are in Maryland, I’d be happy to discuss it further with you, just give me a call. -Scott of DUCTZ of the Upper bay Region, 410-692-9775