Quick answerCentral AC installation in Spokane means a load calculation, a new outdoor condenser, a matched indoor coil on the furnace, a line set, a disconnect and the Washington mechanical permit. Replacing an existing system usually takes one day; adding AC to a furnace-only home takes one to two days depending on the coil space and electrical.
Updated September 2026
Adding or replacing central air
Spokane summers are short, but July and August now bring regular 90 degree afternoons and a few near 100.
If the house already has a furnace and ductwork, central AC slots in on top of it. The coil sits on the furnace, the condenser goes outside on a pad or wall bracket, and a copper line set and a thermostat cable connect the two.
What drives the price of a new AC
Planning range: Published 2026 figures put central AC alone at roughly $3,500 to $12,500 installed depending on SEER2 tier and climate, and a full central system at about $3,750 to $12,000. These are published market figures from 2026-07, given for planning, with the on-site estimate as the real price.
Three ways an AC install plays out
Adding central AC to a furnace-only home
This is the most common install we do in older neighborhoods. We check whether the furnace blower can move enough air for cooling, whether the plenum has room for a coil, and whether the return side is big enough. Then we set the coil, run the line set through the rim joist or wall, pour or place a pad, and add a disconnect and a dedicated circuit at the panel. Undersized returns are the usual problem in older houses, and fixing one at install time is far cheaper than living with a noisy, weak system.
Replacing an old condenser and coil
A like-for-like replacement swaps the outdoor unit and the indoor coil together so the refrigerant, metering device and efficiency ratings actually match. We recover the old refrigerant, flush or replace the line set where needed, pressure test with nitrogen, pull a deep vacuum and charge by the manufacturer's method. Mixing a new condenser with a 20-year-old coil is the most common shortcut in this trade, and it costs the homeowner efficiency and warranty coverage. We do not do it.
High-SEER2 upgrades
Higher-efficiency systems with two-stage or variable-speed compressors run longer at lower output, which pulls more moisture and keeps upstairs rooms steadier. In a climate where cooling runs a couple of months a year, the energy savings take longer to pay back than they would in Texas, so we are straight about the math. The comfort gain is real, and a variable-speed system is often the quieter choice for houses with bedrooms near the condenser. We quote a standard and an upgraded option side by side.
Single-stage, two-stage or variable-speed
| Single-stage | Two-stage | Variable-speed | |
|---|---|---|---|
| How it runs | Full output, on or off | Low most of the time, high on hot days | Adjusts in small steps |
| Comfort upstairs | Swings more | Steadier | Steadiest |
| Noise | Loudest | Quieter on low | Quietest |
| Upfront cost | Lowest | Middle | Highest |
| Fits best | Budget replacements | Most Spokane homes | Large homes, bedrooms near the unit |
What Spokane heat and housing mean for AC
July normals in Spokane sit near 84 degrees, but July 2026 ran almost three degrees above that with a 96 degree peak, and August reached 97. Inside the city the median home dates to 1961 and a quarter predate 1940, and in West Central most homes were built before 1940, so we often add cooling to houses with small returns and ducts designed only for heat. Newer 2026 equipment also uses A2L refrigerants, which affects which coils can be paired.
How an AC installation day goes
- 1
Load calculation
We measure the house and run the numbers before choosing a size.
- 2
Written quote and permit
You approve the system and price; we file the mechanical permit.
- 3
Coil and furnace side
Coil set on the furnace, drain line run, plenum sealed.
- 4
Outdoor unit
Pad or bracket placed, condenser set with snow and service clearance.
- 5
Line set and electrical
Copper run and brazed under nitrogen; disconnect and circuit installed.
- 6
Evacuate and charge
Pressure test, deep vacuum, charge by the manufacturer's method.
- 7
Start-up and inspection
Temperatures and pressures recorded, thermostat set, inspection scheduled.
AC installation questions
Can I add central air if my house only has a furnace?
Usually yes, as long as the furnace blower can move enough air and there is room for a coil.
What size AC does my house need?
It depends on insulation, windows, sun exposure and ceiling height, not just square footage. We run a load calculation so the system is not oversized.
Should I replace my furnace at the same time?
If the furnace is 15 years or older, doing both together saves labor and lets the blower, coil and condenser be matched.
Do I need a permit for a new AC in Spokane?
Yes. Washington requires a mechanical permit even for like-for-like replacements. We file it and schedule the inspection.
Is a heat pump a better idea than AC?
Sometimes. A heat pump cools like an AC and also heats on mild days, which can cut gas use. In Spokane it is best paired with a furnace for the coldest weather. We quote both when it makes sense.
Other cooling services we handle
AC Repair
Answered 24/7, parts on the truck.
AC Repair detailsWhole-House Fan Installation
Sized, quoted and permitted.
Whole-House Fan Installation in SpokaneRefrigerant Leak Repair
Answered 24/7, parts on the truck.
How we handle refrigerant leak repairStay cool the next time it hits 95.
Call to schedule central AC installation in Spokane, WA.
