I just had my air ducts cleaned. My house was built in 1998 (Tierra del Sol north). I'm sure it was the first time to be cleaned. The technician showed me the fan before they began cleaning. It looked like my dryer lint tray after towels were dried. I have bad allergies and when I turned on the heat earlier this year, I was sneezing and blowing my nose all day. My AC company recommended Advanta Clean. 407-973-6352. Very professional. Not cheap, but worth every penny. My AC is even much more quiet. Highly recommend. They even fogged the ducts after cleaning to prevent mold/fungus. Not sneezing now.