These are just some reasons to have your air ducts cleaned:
1. Smells. A smell from the air ducts could indicate several things, dead mice or other small varmints. Your home or past residents could have had one near a vent.
2. New home . Remodel dust sanding doors, walls and floors. Your dust or the previous home owner who fixed up the home to sell. All this goes into the air duct system. You turn on the AC or Heat and it all goes through the system. Removing the carpet with the old pad.
3. Allergies. We remove the dust, pet dander (past or current).
4. Every 3 to 5 years depending on the size of the home should be air duct cleaned.
5. Pet food, some foods drop into the vents from there dish and slowly decay from you or the past owners.
6. A litter box near a vent can put many different air borne (simply put, things in the air).
7. Home fire, flood or mold issues. These things just happen. Air duct cleaning is a must with these.