Air duct cleaning cost

Duct cleaning costs $400 to $1,000 for an average house, typically around $600. It is one of the most aggressively marketed home services in the country and one of the least often necessary, so the useful part of this page is the section on when to skip it.

The Environmental Protection Agency's position is that routine duct cleaning has not been shown to prevent health problems, and that it should be done for a specific reason rather than on a schedule.

What it costs

A $79 whole-house special is a bait price. What arrives is a shop vacuum, a walk around, and a quote for the work that was always going to be quoted.

When it is worth doing

There are real reasons, and they are specific:

• Visible mold growth on the inside of ducts or on the coil. Confirm it is mold before paying for remediation; insulation fiber and dust look similar.
• Rodent or insect infestation in the ductwork, with droppings or nesting material.
• After construction or renovation, particularly drywall sanding. Drywall dust is fine, abrasive and gets everywhere.
• After a fire, for the smoke residue.
• Visible debris blowing from the vents, or dust so heavy at the registers you can see it accumulating.
• A new house where the ducts were used during construction, which happens more than it should.
• Moving into a house where a heavy smoker or many pets lived.

When to skip it

• Because it has "been a while". There is no schedule that means anything.
• Because someone in the house has allergies. The evidence that duct cleaning helps allergy symptoms is weak; the filter, the humidity and the sources in the room do far more.
• Because a mailer says the ducts are full of pounds of dust. They are not.
• Because you were offered $99 and it seemed cheap. It is cheap because it is not the product.

What a proper job looks like

The standard is source removal: the system is put under negative pressure by a large truck-mounted or portable vacuum, and each run is agitated with brushes or compressed air so the debris goes into the vacuum rather than into the house.

That means:

• Every supply and return register opened and covered
• Access ports cut into the trunk lines and properly resealed afterwards
• The blower compartment and the evaporator coil cleaned, since that is where the dirt actually accumulates
• Before and after photographs down the runs

A visit with a shop vacuum at each register is not duct cleaning. Neither is "sanitizing", and chemical fogging into ductwork is not something to accept casually: the EPA notes that few products are registered for use inside ducts.

The thing that is usually the real problem

Most complaints that lead people to duct cleaning are actually about airflow: rooms that never get warm, dust settling faster than it should, a system that runs constantly.

Those are almost always leaky ducts rather than dirty ones. A typical house loses 20 to 30% of its conditioned air through gaps at joints and boots, often into an attic or crawl space. Sealing that is a different job with a measurable result, and it costs $300 to $900 for accessible work.

If the ducts run through an unconditioned attic, sealing and insulating them will do more for comfort and running cost than cleaning them ever will.

Frequently asked questions

How often should ducts be cleaned?

There is no interval. Do it for a reason. If you want a rule, look inside a return register with a flashlight every couple of years and judge by what you see.

Will duct cleaning help my allergies?

Probably not much. A better filter fitted correctly, humidity between 30 and 50%, and dealing with the sources in the rooms will do more. If there is visible mold in the system, that is a different matter and worth acting on.

Is the "pounds of dust" claim true?

No. It is a stock line from a marketing template. Ducts in an ordinary house hold a surprisingly small amount of settled dust, most of it in the first few feet of the returns.

Should I have the dryer vent done at the same time?

Yes, and this one is genuinely worth it. A blocked dryer vent is a real fire risk and it is cheap while someone is already there with the equipment.

What about UV lights and duct sanitizing?

UV lights on the coil have a narrow legitimate use in keeping the coil surface clean in humid climates. Sold as a whole-house air purification measure, they are overstated. Fogged chemical sanitizers are best avoided.