How Much Does AC Installation Cost in Seattle?
Adding central air conditioning to an existing furnace and ductwork typically runs $5,100–$9,800 in the Seattle area, with Angi's Seattle average around $7,377. Washington's roughly 10% sales tax applies to equipment, and electrical work is the most common extra in older homes. Before you commit, price a heat pump too — for many Seattle homes it cools identically in summer, replaces gas heat in winter, and unlocks utility rebates an AC can't.
Typical Seattle-area ranges
Central AC installation
$5,100 – $9,800 typical ~$7,400
New central air conditioner added to an existing furnace/ductwork
Angi's Seattle data averages $7,377. Washington's ~10% sales tax applies to equipment.
Sources: Angi — AC replacement cost, Seattle WA (2025–2026) · HVAC Project Cost — Seattle, WA (2026)
Ducted heat pump installation
$8,000 – $16,000 typical ~$10,200
All-electric heating + cooling using your existing ductwork
Angi's 2026 Seattle average is $10,218; complex retrofits and larger homes trend toward the top of the range. Utility rebates can take $1,500–$6,000 off — see rebates below.
Sources: HVAC Project Cost — Seattle, WA (citing Angi 2026) (2026) · WattFax — 113 WA homeowner quotes (2026)
These are typical Seattle-area market ranges compiled from published cost guides (Angi, HomeGuide, and Seattle-area 2025–2026 cost studies) — market context, not a quote from Glendale Heating & Air Conditioning. Your home's size, equipment, ductwork, electrical, and permits change the number. National figures are marked; Seattle-area labor typically runs above national averages.
AC or heat pump — which should a Seattle homeowner price?
Both, usually. A central AC and a heat pump are the same machine in summer — the heat pump just runs in reverse all winter, displacing gas or electric heating costs. Utility rebates apply to qualifying heat pumps, not straight AC, which can close most of the price gap between the two.
If your furnace is newer and you only need summer cooling, a straight AC keeps the project simpler and cheaper. If the furnace is also aging, pricing the combined heat-pump project is almost always worth the extra quote — we'll run both numbers side by side.
Why did AC become standard in Seattle homes?
Heat waves that used to be rare are now annual, and most of Seattle's housing stock was built without cooling. That's why AC retrofits are one of our most-requested projects — and why sizing matters so much: an oversized unit cools fast but never dehumidifies properly, and an undersized one runs flat-out through every heat dome.
What moves the price up or down?
Tonnage (capacity)
Correct capacity comes from a load calculation using your home's measurements, insulation, and windows — not square footage alone. Sizing mistakes cost comfort and money for the unit's whole 15–20 year life.
Efficiency (SEER2)
Higher-SEER2 equipment costs more up front and less every summer. The right tier depends on how many cooling hours you actually run.
Electrical service
AC condensers need a dedicated circuit and disconnect; older panels sometimes need upgrades. Our technicians hold WA 06A electrical licenses, so this is assessed in the same visit.
Ductwork condition
Cooling pushes more air than heating in many systems — duct leaks that were tolerable with a furnace can undermine a new AC. We test rather than guess.
Permits and tax
Mechanical and electrical permits apply, and Washington's ~10% sales tax applies to equipment. Both belong on the quote, not on a change order.
An honest quote includes
- A load calculation for correct tonnage — in writing
- Exact equipment model numbers with SEER2 ratings
- Electrical work, permits, and refrigerant line details priced up front
- A heat-pump alternative quote when it makes sense for your home
- One total with warranty terms spelled out
Cost questions Seattle homeowners ask
How much does it cost to add AC to a house in Seattle?
Typically $5,100–$9,800 installed for central AC added to an existing furnace and ductwork, with Angi's Seattle average around $7,377. Electrical upgrades and duct repairs are the most common extras in older homes.
Is it cheaper to install AC or a heat pump?
Straight AC usually costs less up front ($5,100–$9,800 vs. $8,000–$16,000 ducted), but heat pumps qualify for utility rebates of $1,500–$6,000 and reduce winter heating bills — over the equipment's life, many Seattle homes come out ahead with the heat pump. We quote both so you can compare.
What size AC does my home need?
The honest answer comes from a Manual J load calculation, not a rule of thumb. Oversized ACs short-cycle and leave rooms clammy; undersized ones can't keep up in a heat wave. We size from your home's actual measurements.
How long does an AC installation take?
Most straightforward add-on installs are done in one to two days, including the electrical work and inspection scheduling. Complex ductwork or panel upgrades add time — your written quote includes the schedule.
Ready for comfort you can count on?
Whether it's a furnace that quit on a cold morning or a whole new system, the Glendale team is ready. Honest pricing, expert work, and 87+ years behind every visit.
Hours & Emergency
- Mon–Sat: 8:00 AM – 7:00 PM
- Sun: Emergency On-Call Only
- Emergency line: (206) 243-7700