Ducts carry all the heated and cooled air in your house. When they leak, some of that air ends up in the crawl space or attic instead of the rooms you are paying to condition. Summit Heating & Air tests, seals, and repairs duct systems throughout Boise and Boise, Meridian, Nampa, Eagle, and Kuna. We measure how much air the ducts lose before we recommend anything, and we measure again when the work is done. Sealing options include mastic applied by hand on accessible joints, and an aerosol sealant blown through the system that reaches joints buried in walls and under floors. Repairs cover crushed flex duct, disconnected runs, rusted boots, missing returns, and uninsulated sections. Sealed ducts usually deliver more air to the far rooms, keep crawl space dust out of the system, and shorten furnace and air conditioner run times. We do not promise a specific savings figure. We show you the leakage numbers instead.
Signs your ducts are leaking
- The far bedroom never gets as warm or cool as the living room
- Dust builds up fast even with a good filter
- The furnace or AC runs long cycles but the house lags behind
- A musty or earthy smell from the vents after startup
- Visible gaps, tape, or sagging flex duct in the crawl space
- Heating and cooling bills higher than similar homes nearby
What duct sealing and repair covers
- Duct leakage test with a calibrated fan before and after the work
- Visual inspection of every accessible run in the crawl space, basement, or attic
- Mastic and mesh sealing of joints, boots, and plenum connections
- Aerosol internal sealing for ducts that cannot be reached by hand
- Replacement of crushed, disconnected, or rusted sections and added returns where needed
- Insulation on ducts running through unconditioned space
How duct sealing works with us
- We inspect the duct system, take static pressure readings, and run a leakage test to get a baseline.
- You receive a written report with the leakage number, photos of the problem areas, and a fixed price for the fix.
- Our crew repairs the broken sections first, then seals joints by hand or with aerosol sealant from the inside.
- We retest the system, compare the before and after numbers, and check airflow at each register.
- You get the final report with both test results and the photos, so you can see exactly what changed.
Duct repair and sealing cost in Boise
A duct leakage test starts from $150 and is credited toward sealing work if you go ahead. Hand-sealing accessible ducts in a crawl space or basement starts from $900. Aerosol sealing from the inside, which reaches joints that cannot be seen or touched, starts from $2,000 for a typical single-system home. Repairs to crushed or disconnected runs are priced per section. Cost depends on the size of the duct system, how accessible it is, the number of registers, and whether new returns or insulation are part of the job. We give a fixed price after the inspection and test.
Why Boise ducts leak
Most Boise homes sit on a crawl space, and most ductwork runs through it. Crawl spaces here are dry compared with wetter climates, but they are dusty, and a leaky return pulls that dust straight into the house. Homes on the Bench and in the North End often have original sheet metal ducts from the 1950s and 1960s with joints that were never sealed, or flex duct added when central air was retrofitted. Newer subdivisions in Meridian used flex duct that can sag, kink, or pull off boots as the house settles. Kuna builders used the same material. Boise's hot summers and cold winters both make leaks costly, since air lost to the crawl space in July matters as much as in January.
Questions we get about this
How do you know how much my ducts leak?
We seal off the registers and pressurize the duct system with a calibrated fan, then measure how much air it takes to hold that pressure. The result is a leakage number in cubic feet per minute. We test before and after so you can see the change.
Is duct tape a fix?
No. Cloth duct tape dries out and falls off within a few years, especially in a hot attic or a dusty crawl space. We use mastic, a paint-on sealant that stays flexible, along with foil tape rated for ducts and mesh on larger gaps.
What is aerosol duct sealing?
A sealant is atomized and blown through the duct system while the registers are blocked. The particles collect at leaks and build up until the gaps close. It reaches joints inside walls and under floors that no one can touch. Results are measured on the spot.
Can sealing fix a room that is always cold?
Often, yes. If the run to that room is leaking, disconnected, or crushed, fixing it restores airflow. If the room simply has no return or the duct is undersized, we may need to add a return or resize the run. The inspection tells us which.
Do you insulate ducts?
Yes. Ducts running through an unconditioned crawl space, garage, or attic lose heat through the metal walls even if they do not leak. We wrap them with duct insulation after sealing. Sealing comes first, since insulation does nothing for air escaping through a gap.
Will sealing my ducts make the house dustier or cleaner?
Cleaner. Leaky returns pull dust, insulation fibers, and crawl space air into the system and blow it into the rooms. Sealing the returns stops that. Many homeowners notice less dust on furniture and slower filter loading in the months after sealing.