I am skeptical about the benefits of duct cleaning as preventative maintenance. Ads that say “your house may be making you sick” appear as fear mongering. What are the risks of never cleaning one’s ducts? How much does it cost for the typical house (none of the sites I went to had pricing information, “call for a free inpsection”)?
If there is a measureable risk and the price is commensurate, how often should ducts be cleaned?
Duct cleaning: saving lives or selling snake oil?