How Often Should Air Ducts Be Cleaned? A Treasure Valley Answer | Dirty Ducts Boise
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How Often Should Air Ducts Really Be Cleaned?

The honest schedule for a Treasure Valley home, situation by situation — including the cases where the right answer is "not yet." Written by the guy who turns those jobs down.

Written by Michael Lossing, owner · 4,700+ Treasure Valley homes · QUADCA-certified · 5.0 on Google
The Short Answer

Every 3 To 5 Years For Most Treasure Valley Homes — Sooner In A Few Specific Cases

If your home is average — a family, maybe a pet, no recent remodel, a filter that gets changed most of the time — a full-system cleaning every three to five years keeps the ductwork clean. The valley's air pushes most homes toward the three-year end of that range. Several situations move it to "now." Here is the whole list, honestly, including the cases where the answer is "not yet."

Your situationHow oftenWhy
New construction, first two yearsOnce, soon.Drywall dust, sawdust, insulation and packaging are sealed in the ducts before move-in and circulated ever since. A first cleaning on a 2-to-5-year-old home routinely fills the bag.
Just bought a homeBefore you move in, or soon after.You are breathing the previous owner's pets, smoke and habits. Nearly every resale home in Boise has never had the system opened.
After a remodelRight after.Drywall and tile dust is fine enough to pass a standard filter. It ends up on the coil and in the trunks and comes back out for months.
Pets that shed, allergy or asthma sufferersEvery 2–3 years.Hair and dander load the returns; dust returning within days of cleaning the house is the tell.
Wood-stove or fireplace wintersEvery 3 years.Fine ash circulates through the furnace blower even when the stove does the heating. The smoke smell lives in the trunk lines.
Bad wildfire-smoke summerThat fall.Smoke particulate coats the inside of the system and the coil. It does not leave on its own.
Rodents, water damage or visible moldNow, plus the underlying fix.Cleaning removes the contamination; it does not stop the leak or the entry point. We will tell you which trade you need.
Cleaned within the last 3 years, no changesNot yet.We will camera it if you want, and tell you honestly if it is fine. We turn these jobs down regularly.
Why The Valley Is Different

Four Things Treasure Valley Air Does That Shorten The Timeline

National guidance from industry certification bodies says every three to five years for a typical home. The Treasure Valley is not a typical place to run a furnace, which is why we lean toward three.

Winter inversions

When cold air gets trapped under a warm layer over the valley — which happens most winters for days at a time — particulate has nowhere to go. Your furnace runs the most during exactly those weeks, and the return side of the system pulls that air in.

Wildfire smoke season

Late-summer smoke from Idaho, Oregon and California parks over the valley most years. Smoke particulate is small enough to pass a standard furnace filter and coats the inside of the trunk lines and the coil.

Farm, construction and foothills dust

Meridian, Kuna, Star and Nampa have some of the most active construction in the state; Caldwell, Emmett and Payette sit next to working ground; the north side of Boise gets dry foothills dust on every breeze. All of it comes in on open windows and ends up in the returns.

Cottonwood and pollen

June cottonwood along the river and the canals fills returns with fluff, and sagebrush and grass pollen follow. If someone in the house has allergies, the ductwork is holding a season's worth.

The Honest Part

Why We Will Not Tell You To Clean Every Year

Some companies recommend annual duct cleaning. That is a recurring-revenue plan, not a maintenance schedule. A properly cleaned system with a decent filter does not reload in twelve months, and cleaning ductwork that is already clean does nothing for your air.

What actually protects the system between cleanings is boring: change the furnace filter on schedule (every 60 to 90 days, more often with pets or smoke), keep the returns unblocked, and clean the dryer vent every year — that one really is annual, because lint is a fire risk, not a dust problem.

We camera every system before we quote a cleaning as needed. If it is clean, we say so and leave. One of our most-read Google reviews is from a homeowner we turned down. That is the standard.

Rule of thumb: if you cannot remember the last time the ducts were cleaned, it has been long enough. If it was within three years and nothing on the table above has happened, it has not.
How To Tell

Signs It Is Due Now, Not In Two Years

You do not have to guess. These are the signs we hear most from Treasure Valley homeowners who turned out to need it.

  • Dust back on surfaces within a day or two of cleaning the house.
  • Allergy or asthma symptoms that get worse when the furnace or AC runs, and better when it is off.
  • A musty or "hot dust" smell from the registers the first cold morning of the year.
  • Visible debris, hair or dark streaking at the supply registers or on the return grille.
  • Uneven airflow — one room barely gets air — or a furnace that runs longer than it used to.
  • You just moved in, just remodeled, or just got through a smoke summer.

Full list with photos on our signs your ducts need cleaning page. Still unsure? Send us the address — a camera look costs nothing and we will tell you straight.

What A Cleaning Includes

When It Is Time, This Is What "Cleaned" Should Mean

The reason a proper cleaning lasts three to five years is that it is a whole-system job, not a register wipe. Every one of these is included at one price by the square foot — see the cost guide for the numbers.

Every supply registerEvery room, every floor
Every return & return lineCleaned end to end
Main trunk linesOpened and cleaned — where the debris lives
Both plenumsSupply and return
Furnace evaporator coilIncluded
Camera inspectionBefore and after
Botanical sanitizingHospital-grade, no bleach
Dryer vent, optional$49 while the truck is there
3-month workmanship warrantyEvery job
Straight Answers

Questions People Ask Right After This One

It helps — a MERV 8 to 11 filter changed every 60 to 90 days catches most of the household dust. It does not touch what is already in the trunk lines, and it does not stop fine smoke or remodel dust.

After. Drywall and tile dust gets into the system during the work no matter how well the registers are taped. Cleaning first just means cleaning twice.

Ask for the invoice or the before-and-after video. If there is neither, we will camera it for free and show you.

Every year, regardless of duct cleaning. Lint is a fire risk, and a roof-exit run on a two-story home clogs fast. Details on our dryer vent page.

Fall, before the furnace runs hard and before inversion season — and in farm towns, after harvest. Spring is second-best, after the pollen and before the AC. We work year-round; those are just the times it pays off fastest.

Two to four hours for a single-system home. You do not need to leave or move furniture.

Free, No-Obligation

Not Sure Where Your Home Stands?

Send us the address. A camera look is free, and we will tell you straight whether it needs cleaning or can wait.

No hidden fees. No bait-and-switch. 3-month workmanship warranty. 100% Satisfaction Guaranteed.