Any thoughts on how often you need to have your ducts cleaned? I have a 7 year old house in a dusty area of Texas. Do I need to have them cleaned? Any symptoms of needing a clean? What should it cost? Thanks in advance.

The general consensus is that it's a waste of time with the potential to damage the inside of your flex ducts. Cleaning the coil in your air handler is a good idea though.

FWIW I checked out a section of ducting that I removed during our huge kitchen-living areas renovation and there was next to no dust in it. It was about 11 years old at that point and had already been through all of the demo and dust that I kicked up for several months of work.