Ductwork Installation in SeaTac, WA
Custom sheet metal ductwork fabricated and installed serving Angle Lake, McMicken Heights, Bow Lake, and all of SeaTac. No subcontractors, all permits pulled, built to exceed WA code. Served by Puget Sound Energy or Seattle City Light depending on the address — we confirm which before quoting a rebate.
Your SeaTac Ductwork Specialists
SeaTac homeowners in Angle Lake, McMicken Heights, and Bow Lake often discover that ductwork is the silent culprit behind comfort and efficiency problems. Many homes in SeaTac were built when furnaces were oversized, fuel was cheap, and ductwork was sized for low static pressure. Modern high-efficiency equipment — variable-speed furnaces, two-stage ACs, heat pumps — needs properly sized ducts and tight seals to deliver rated performance. Original ductwork in older SeaTac homes is often undersized, leaky at every joint, and missing insulation in unconditioned spaces.
SeaTac is the code table station — the 24°F design temperature every neighboring city borrows is measured at the airport here — and many homes were re-insulated under the Port sound-insulation program, which changes the load calculation. Because the boundary runs through SeaTac rather than around it, the first thing we do is read your power bill — quoting a rebate you cannot claim is not a favour.
The Washington State Energy Code lists SeaTac at a 24°F winter design temperature (WAC 51-11C-80100, Table C-1). That is the number a Manual J load calculation for your home is run against, and it is the difference between duct runs sized for the real load and duct runs sized for a guess. Natural gas here comes from Puget Sound Energy. In SeaTac we most often find electric baseboard and wall heaters in the 1950s–70s ramblers, gas forced air in split-levels, and Port of Seattle sound-insulation-program windows and insulation that changed the original load — so we quote what your house actually has, not what the average Puget Sound home has.
Ductwork Services for SeaTac Homes
Why SeaTac Homeowners Choose Us
Fast Response
Based in Federal Way, we reach SeaTac quickly for ductwork inspections and estimates. Most ductwork projects are scheduled within a week of approval.
Know Local Codes
The mechanical permit for your duct system is issued by the City of SeaTac Community & Economic Development Department. We pull it, pay the fee, book the inspection and meet the inspector on site.
Understand Local Homes
In SeaTac we usually find electric baseboard and wall heaters in the 1950s–70s ramblers, gas forced air in split-levels, and Port of Seattle sound-insulation-program windows and insulation that changed the original load. We size to your house at the 24°F design temperature the state energy code sets for this area — not to a rule of thumb.
Ductwork Challenges for SeaTac Homes
Who bills you for power decides what you can claim. SeaTac is served by Puget Sound Energy or Seattle City Light depending on the address. PSE's current heat pump incentive is if PSE is the name on your power bill, up to $4,400 toward a qualifying heat pump replacing an existing electric or fossil-fuel system — the exact amount depends on what you are replacing and the equipment you install. PSE pays $1,500 for an electric-resistance conversion plus a $2,400 income-based boost; Seattle City Light runs its own program. We confirm which one you are on before quoting. Both programs pay only through their own approved installer lists — PSE has required a Trade Ally or Registered Energy Professional since April 2, 2026 — so the utility on your bill decides both the amount and who is allowed to earn it for you.
SeaTac does not share Seattle's weather, and the code says so. The Washington State Energy Code lists SeaTac at a 24°F winter design temperature (WAC 51-11C-80100, Table C-1). That is the number a Manual J load calculation for your home is run against, and it is the difference between duct runs sized for the real load and duct runs sized for a guess. Kent is 21°F — a real gap for towns this close together. SeaTac is the milder side of that line, and equipment sized for the colder neighbor is equipment you paid too much for.
What we expect to find in a SeaTac home. The local stock runs to 1950s-1970s ramblers and split-levels, apartment complexes, and moderate-density housing near the airport. That usually means electric baseboard and wall heaters in the 1950s–70s ramblers, gas forced air in split-levels, and Port of Seattle sound-insulation-program windows and insulation that changed the original load. Gas service here comes from Puget Sound Energy. Whether reworking a duct system is the right answer for your house is something we tell you after we look at it, not before.
The parts of the job that are specific to this address. In SeaTac, the mechanical permit is issued by the City of SeaTac Community & Economic Development Department, and we pull it, pay it and meet the inspector; burn bans and wildfire-smoke advisories here are called by Puget Sound Clean Air Agency, which is the season that makes filtration worth specifying properly.
Quick Facts
Local details that change a duct system job in SeaTac
SeaTac is split between two power utilities running two different rebate programs, so half the table below depends on your address rather than your city. We check the bill before we quote.
- Electric utility
- Puget Sound Energy or Seattle City Light depending on the address (check your bill — the boundary runs through town)
- Natural gas
- Puget Sound Energy
- Winter design temp
- 24°F WSEC Table C-1, WAC 51-11C-80100
- Mechanical permit
- City of SeaTac Community & Economic Development Department
- Rebate program that applies
- PSE or Seattle City Light
- Burn bans & smoke advisories
- Puget Sound Clean Air Agency
- Heat we usually find
- electric baseboard and wall heaters in the 1950s–70s ramblers, gas forced air in split-levels, and Port of Seattle sound-insulation-program windows and insulation that changed the original load
“Vlad and his team were extremely professional. Constant communication, clean workmanship, and reasonable pricing.”
— Darius T., Federal Way, WA
Ductwork Questions from SeaTac Homeowners
Ductwork projects in SeaTac typically range from $3,000 to $8,000, depending on scope. A partial replacement of a few crushed or leaking runs is at the lower end. A complete custom-fabricated duct system for a 2,000-3,000 sq ft home with all-new trunk lines, mastic sealing, and R-8 insulation is at the higher end. We provide free in-home assessments with written, itemized estimates.
Yes. The mechanical permit is issued by the City of SeaTac Community & Economic Development Department, and Washington State requires one for this work. We handle the whole thing — application, fee, and meeting the inspector for the final — so you never contact the permit desk yourself. Every install meets or exceeds the current Washington State mechanical and energy codes.
Most ductwork projects in SeaTac take 1-3 days. A targeted replacement of a few problem runs is often a one-day job. A complete duct system replacement paired with a new furnace or heat pump install runs 2-3 days, including commissioning and balancing. We schedule to minimize disruption and always leave your home clean.
Almost always, the cause is ductwork: undersized supply, missing or unbalanced damper, kinked flex duct, leaky takeoff, or no return air path. We diagnose the actual cause with manometer readings and airflow measurements — not guesses — and propose the smallest fix that actually solves the problem.
We fabricate our own galvanized sheet metal trunk lines, plenums, and transition fittings. We use rigid metal supply runs wherever possible and limit flex duct to short, properly supported connections at registers. All joints are sealed with mastic (not tape). All ducts in unconditioned space (attics, crawl spaces) are insulated to R-8 minimum. No subcontractors and no shortcut materials.
Often, yes — at minimum, you should have it inspected. A new high-efficiency furnace or variable-speed heat pump can lose 20-30% of its rated performance through leaky, undersized, or improperly sealed ductwork. If your existing ducts are 25+ years old, leaking visibly, or were sized for a smaller previous unit, it's almost always worth replacing or modifying them as part of the equipment install.
The Washington State Energy Code lists SeaTac at a 24°F winter design temperature (WAC 51-11C-80100, Table C-1). That is the number a Manual J load calculation for your home is run against, and it is the difference between duct runs sized for the real load and duct runs sized for a guess. A cold-climate heat pump holds its rated capacity well below that, which is why heat pumps genuinely work here rather than being a compromise. Gas here comes from Puget Sound Energy, and for some homes a hybrid — heat pump for most of the year, gas furnace for the coldest mornings — is the right answer. We will tell you if it is.
Ductwork Near SeaTac
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Honest pricing on ductwork installation, replacement, and modification — fabricated by our own sheet metal crew.