According to the EPA (United States Environmental Protection Agency) website, you should have your ducts cleaned if:
- There is substantial visible mold growth inside hard surface (e.g., sheet metal) ducts or on other components of your heating and cooling system.
- Ducts are infested with vermin, e.g. (rodents or insects)
- Ducts are clogged with excessive dust and debris, and/or particles are released into the home from your supply registers.
There is no scientific proof that duct cleaning will prevent health problems, but it certainly will
help with the dust and particles you breathe inside your home.
If you already have an existing health condition, IAQ (Indoor Air Quality) should be a top priority.