The short answer: for most homes in Western Massachusetts and Northern Connecticut, every three to five years is a reasonable rhythm, which is the range NADCA generally points homeowners toward. But a calendar is a blunt tool. Some houses need it sooner, and some can go longer. The better question is whether anything has happened to your system since the last time someone looked inside it.
Why There Isn't One Number for Everybody
The EPA's position is that duct cleaning shouldn't be done on a fixed schedule just because a postcard said so. It should be done when there's a reason. We agree with that, and we're the ones who'd make money if you called every year.
What the three-to-five-year range really reflects is how long it takes an ordinary household to build up enough dust, skin cells, and lint in the ductwork that it starts showing up elsewhere: on the registers, on the furniture a day after you dust, in the filter that turns gray faster than it used to. A quiet house with two adults and a good filter can stretch past five years. A busy one can't.
Things That Move You Toward Sooner
A few situations reliably shorten the clock:
- Pets. Dogs and cats shed into the return side of the system every day. Two big shedders can make a two-year house out of a five-year one. More on that in duct cleaning when you live with pets.
- Renovation. Drywall dust is fine enough to go straight through a standard filter. If you sanded, demoed, or refinished floors with the system running, that dust is in your ducts now. See what construction dust does to your system.
- Moving into a house. You don't know what the last owners did, or didn't do. A first cleaning resets the baseline.
- Mold, pests, or water. Any visible growth, droppings, or a flooded basement with ductwork in it is a reason to look now, not in three years.
- Allergies or asthma in the house. Not because cleaning cures anything, but because there's less in the air to set people off.
Things That Let You Go Longer
A newer system with sealed ductwork, a good pleated filter changed on schedule, nobody smoking indoors, no pets, and no projects. If that's your house, you may honestly be fine for a while. A quick inspection will tell you more than any rule of thumb.
What New England Adds to the Equation
Our houses work hard. The heat runs for six or seven months, the air conditioning for two or three, and a lot of systems live in basements and crawl spaces that stay damp. Older homes in places like Holyoke, Chicopee, and Northampton often have ductwork that was added decades after the house was built, with joints that leak and pull in basement air. All of that tends to push homes toward the sooner end of the range.
If you're not sure, the six signs your air ducts need cleaning are a good gut check.
What About Businesses?
Commercial HVAC follows the same logic, just with more people breathing the air. Offices, schools, and medical buildings usually get inspected on a schedule set by the facility manager and cleaned when the inspection says so.
Commercial kitchens are different, because the schedule isn't optional. NFPA 96 sets kitchen exhaust cleaning frequency by cooking volume: monthly for solid-fuel cooking, quarterly for high-volume operations like 24-hour kitchens or heavy charbroiling, semi-annually for moderate volume, and annually for low-volume kitchens like churches or seasonal camps. Our NFPA 96 frequency guide walks through it.
Don't Forget the Dryer Vent
Separate job, separate schedule. A dryer vent should be checked once a year, especially in a house with kids and a lot of laundry. It's a fire safety issue more than an air quality one, and it's not the same job as duct cleaning.
The Practical Version
If it's been more than five years, or you can't remember, have someone look. If something on the "sooner" list happened, have someone look. If neither is true, change your filter and check back next fall. That's really all there is to it.
