The three situations where it’s worth it
The EPA doesn’t recommend cleaning air ducts routinely, only as needed. Its guidance comes down to three situations:
- Substantial visible mold growth inside hard-surface ducts or on other parts of the heating and cooling system. The moisture problem has to be fixed too, or the mold comes back.
- Ducts infested with vermin, such as rodents or insects.
- Ducts clogged with so much dust and debris that particles are released into the home from the supply registers.
What air duct cleaning won’t do
It isn’t a health treatment. The EPA says duct cleaning has never been shown to actually prevent health problems, that studies don’t conclusively show dust levels in homes rise because of dirty ducts, and that a light amount of household dust in ducts poses no known health risk.
It isn’t a reliable way to cut your power bill either. The EPA says little evidence exists that cleaning only the ducts improves a system’s efficiency. Anyone promising a percentage in savings is getting ahead of the evidence.
When it’s a waste of money
Duct cleaning is usually wasted money when it’s done on a calendar schedule with nothing wrong, when a chemical spray or fog stands in for mechanical cleaning, or when a $99 whole-house special grows into a much bigger bill once the crew is inside.
NADCA warns homeowners about extremely low-cost whole-house specials that clean only part of the system, and the EPA puts typical duct cleaning at roughly $450 to $1,000 per heating and cooling system.
If you do hire someone
The EPA’s advice for choosing a duct cleaner, plus the method NADCA describes for proper cleaning:
- Get written estimates from at least three companies.
- Ask each one to show you the contamination that makes cleaning worthwhile.
- Skip any company that makes sweeping health claims or recommends duct cleaning as a routine job.
- Expect the crew to protect carpet and furniture, use vacuum equipment that exhausts outside or HEPA vacuuming, use soft-bristled brushes on fiberglass duct board, and close and re-insulate any access holes.
- Treat chemical sanitizers as optional, and only after mechanical cleaning.
- Ask whether the system is kept under continuous negative pressure while debris is loosened and collected, the method NADCA describes.
How we approach it
We look first and show you photos before any cleaning starts. If your ducts don’t meet one of the EPA’s reasons, we tell you, and we don’t sell duct cleaning as a health treatment or an energy saver.
When cleaning does make sense, we clean the supply and return runs, protect your home along the way, and show you before-and-after photos of the result.