Same-Day Service
Most service calls handled same-day across Spokane and Coeur d'Alene.
Duct Repair & Replacement
Better ducts, better comfort, lower bills.
Up to 30% of conditioned air in a typical home is lost through leaky, undersized, or poorly routed ductwork — money, comfort, and quiet operation literally going up the attic. The fix isn’t a bigger AC. It’s better ducts.
We diagnose duct problems with proper instruments — Manual D sizing checks, static-pressure measurements, and visual inspection — then quote a flat-rate fix. Repairs include sealing with mastic or aeroseal, sizing corrections, and full replacement when needed. Pair with a tune-up or new install for maximum impact.
- Manual D sizing Industry-standard load calc for ductwork — not "we always use 8-inch trunks".
- Static pressure tested Measure actual restriction across your duct system — find what's undersized.
- Sealing reduces loss Properly sealed ducts cut conditioned-air loss from 20–30% down to 5%.
- Quieter operation Right-sized ducts cut the whoosh-and-rattle of an undersized system.
Symptom Check
Signs your ductwork needs work
Most "AC isn't cooling well" complaints turn out to be duct problems, not equipment problems. Some warning signs:
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Hot or cold rooms
Big temperature differences between rooms almost always trace back to duct sizing or balance.
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Loud or whistling vents
Air noise at the registers is a classic sign of undersized supply or return ducting.
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High energy bills
Conditioned air leaking into attics, crawls, and unconditioned basements drives bills up.
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Weak airflow
Disconnected branches, kinked flex duct, or crushed runs starve registers.
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Dust everywhere
Leaky return ducts pull dust from attics and crawls — distributing it through the home.
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AC freezing up
Restricted airflow from poor ductwork is a top cause of frozen evaporator coils.
What We Do
Full ductwork service
Repair, seal, redesign, or replace — driven by what your house actually needs, not a one-size-fits-all upsell.
- Duct inspection Visual + static-pressure check + Manual D sizing review.
- Manual sealing Mastic and metal-tape sealing of joints, seams, and connections.
- Aeroseal sealing Aerosolized sealant pumped through ducts to seal leaks from the inside.
- Trunk & branch repair Replace damaged sections of trunk, branch, and flex without ripping out the whole system.
- Resize & rebalance Correct undersized supply or return runs — install dampers and balance airflow.
- Full duct replacement Properly designed and installed ducts when the existing system is past saving.
- Zoning systems Two- and three-zone ducted systems with motorized dampers and zoning controls.
- Insulation & support R-8 insulation, proper hangers, and code-compliant duct support throughout.
How It Works
Our 4-step duct service process
Inspection-first. We never sell ductwork without measuring it.
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Call & schedule
Speak to a real dispatcher 24/7. Inspections typically scheduled within 24–48 hours.
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Inspect & measure
Visual inspection, static pressure, and Manual D sizing review with a written report.
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Quote the options
Repair, seal, redesign, or replace — flat-rate quotes for each, no pressure.
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Fix & guarantee
Most repairs done same-day. Larger projects scheduled at your convenience.
Current Specials
Save on the work your home needs most.
Why Choose Mainstream
Upfront Pricing
Flat-rate pricing approved before work begins — no surprises on the invoice.
Licensed & Insured
Fully licensed in Washington and Idaho, bonded, and insured for your protection.
Satisfaction Guaranteed
If it isn't right, we make it right. Period.
Hot or cold rooms? Often it's the ducts.
Same-day service across Spokane & Coeur d'Alene — flat-rate pricing, no surprises.
What Our Customers Say
Don't just take our word for it — hear from our satisfied customers
★★★★★
Ricky Saldana the technician that came out was fantastic. He was so knowledgeable about my plumbing issues and his recommendations were spot on. He was on time and very pleasant to work with. I would highly recommend him for any plumbing work that needs to be done.
Thanks Ricky for all of your input.
★★★★★
Jake was on time and very good about looking at my furnace. I appreciate all his help. I reccomend him and mainstream electric very highly. thank you Sharon Scott
Maintenance Membership
Join the Care Club
Total home service care, on a schedule.
Members get priority scheduling, seasonal HVAC tune-ups, an annual plumbing & electrical safety inspection, and exclusive discounts — for less than the cost of a single emergency call.
- Priority scheduling
- Seasonal HVAC tune-ups
- Annual safety inspection
- Exclusive member discounts
- Free dispatch on repairs
- No long-term contracts
Duct Repair — Frequently Asked Questions
How do I know if my ducts are leaky?
Visual inspection and static-pressure testing are the two main tools. We can also pressure-test the duct system to measure leak rate quantitatively. Most homes have 20–30% leak rate; under 5% is the goal after sealing.
Aeroseal vs. manual sealing — what's the difference?
Manual sealing (mastic + tape) is the standard for accessible joints and seams. Aeroseal injects an aerosolized sealant through the duct system to seal leaks from the inside — best for ducts in inaccessible locations like wall cavities. We use both, depending on the situation.
Do I need new ducts or can existing ones be saved?
Most existing ducts can be repaired and re-balanced. Full replacement is usually only needed if the trunks are severely undersized, the layout is fundamentally wrong, or the existing duct is damaged beyond repair. We’ll show you the inspection findings and quote both options when both are reasonable.
How long does duct work take?
Sealing and minor repairs typically take a single day. Larger redesigns, zoning installs, or full replacements can take 2–4 days. We confirm the schedule when we finalize the quote.
Will I see lower energy bills?
Yes — most homes see 10–20% reduction in cooling and heating costs after a properly sealed and balanced duct system. Comfort improvements (more even temperatures, quieter operation) are usually noticed first.
Is the work warrantied?
Every repair includes a 1-year Mainstream labor warranty. New duct installations include a 2-year Mainstream labor warranty plus manufacturer warranties on materials.
*Offers cannot be combined with other promotions or applied to dispatch fees. No cash value. Must present offer at time of service. Call for details.
