Locally-owned since 1977 • Licensed, bonded and insured in Washington (WA Contractor Reg. #HOMECCA785BD) • NATE-certified technicians • Carrier Factory Authorized Dealer
Air Conditioning in Des Moines, WA
Central AC, heat pumps and ductless mini-splits: our Sumner team installs, fixes and services all three in Des Moines. Call (425) 645-0404 or use the form. If you are adding or replacing a system, a comfort advisor measures the house and puts the options, rebates and financing on paper.
Why Des Moines homes get warm
A breeze off the Sound keeps most summer days comfortable, but a few things work against that here:
- West-facing glass. View homes are built to look west over the water, and those big windows soak up the late-afternoon sun.
- Closed windows near the airport. Under the Sea-Tac flight path, a lot of people keep the windows shut for the noise, which traps the heat.
- Top-floor condos. Units under the roof near the marina and along Pacific Highway heat up fast and cool down slowly.
- Heat waves. The late-June 2021 heat dome showed how quickly a house with no cooling becomes hard to sleep in.
Cooling costs around Des Moines
Published estimates, not our prices:
| Work | Typical range | Source |
|---|---|---|
| AC or HVAC repair | About $350 average; $100 to $3,000 | Angi, HVAC repair costs, 2026 data |
| Central AC replacement, Seattle area | $5,098 to $9,785, about $7,377 | Angi, Seattle AC replacement costs, updated August 2026 |
| Ducted heat pump, Seattle area | $3,160 to $20,000 depending on efficiency | Angi, Seattle heat pump installation costs, updated July 2026 |
| Ductless mini-split, one zone | $2,222 to $5,555 | Angi, Seattle mini-split costs, 2026 data |
Which system fits your home
| Option | Good fit for |
|---|---|
| Central AC added to your furnace | Houses with sound ductwork and a newer gas furnace |
| Ducted heat pump | Houses with ducts that want cooling and lower heating bills |
| Ductless mini-split | Condos, apartments, homes with wall heaters or baseboards, and hot upstairs rooms |
| Heat pump with gas furnace backup | Gas homes that want the heat pump to carry most of the year |
Because it is only needed a few weeks a year, we usually steer people toward a system that also heats, like a heat pump, so the equipment earns its keep all year.
Condos and HOAs
Cooling a condo takes some coordination. The outdoor unit needs an approved spot, often a balcony, a roof or a wall bracket, and the line set has to run in a way the building allows. We give you a written proposal with the equipment and placement so you can take it to the HOA, and we plan the install around the building’s rules on work hours and access.
Salt air and outdoor units
Close to the water, salt air eats at aluminum coil fins and electrical terminals. For homes in Redondo, Woodmont, Zenith and along the bluff, we talk through coil coatings, placement out of the direct wind, and a gentle rinse of the outdoor coil each spring. Units near the water that get a yearly service tend to last longer than ones left alone.
Upstairs rooms that stay hot
In two-story houses the bedrooms upstairs are usually the last to cool and the first to heat up. The causes are almost always the same: too few return vents upstairs, leaky ducts in a hot attic, and a single thermostat downstairs. Depending on the house, the fix is balancing the airflow, sealing ducts, or adding one ductless head upstairs.
Keeping it quiet
Neighbors are close on many Des Moines streets, and outdoor units can end up under someone’s bedroom window. We look at where the unit will sit relative to your windows and the neighbors’, pick quieter variable-speed equipment when noise matters, and set units on pads or brackets that keep vibration down.
Simple steps before you buy
Some of the heat can be kept out before any equipment runs. Close blinds on the west side by early afternoon, add reflective window film on the worst glass, run bath and kitchen fans to push hot air out, and make sure attic vents are clear. None of this replaces cooling on the hottest days, but it lets a smaller system do the job.
Common AC problems
| Problem | Usual cause |
|---|---|
| Outdoor fan not spinning, unit humming | Failed capacitor or contactor |
| Air not cold enough | Refrigerant leak, dirty coil or clogged filter |
| Ice on the copper lines | Low airflow or low refrigerant |
| Water around the indoor unit | Blocked condensate drain or failed pump |
| Ductless head dripping or musty | Dirty filter or coil, blocked drain |
| Breaker trips on startup | Compressor or wiring fault |
Smoke days and indoor air
Wildfire smoke has drifted over Puget Sound during several recent summers, often during warm spells. With a cooling system, you can keep the house closed on those days. Pair it with a higher-rated filter and run the fan so air keeps passing through the filter.
Spring tune-up
A spring visit gets the system ready for the first hot week. Expect a coil cleaning, refrigerant readings, a capacitor and contactor test, a clear condensate line, an airflow check and a thermostat test.
Permits and rebates
The City of Des Moines issues mechanical and electrical permits through MyPermits Online (City of Des Moines, permit applications and information), and it inspects its own electrical work (L&I, cities that do their own electrical permits). We pull the permits and book both inspections. PSE, which supplies Des Moines (City of Des Moines, Community Services Directory), rebates heat pumps that replace electric heat or are added to a gas furnace (PSE electric resistance to heat pump rebate; PSE hybrid heat pump rebate). More on our PSE rebates page.
Get an estimateA comfort advisor will call you to set up your visit.
How we install
In Puget Sound homes since 1977, and licensed, bonded and insured in Washington (WA Contractor Reg. #HOMECCA785BD). The advisor sizes the system to the house, and the circuit, equipment and startup stay with our own crew. Read more about cooling installation or see all Des Moines services.
Warranty and Home Comfort Club
We support the manufacturer’s warranty on covered equipment parts, and we stand behind our cooling installations with a 1-year labor warranty from installation.
Join our Home Comfort Club, a monthly membership starting at $15 a month, and a new system we install gets extended labor coverage for as long as your membership stays active, up to 5 years from installation. Ask your technician or comfort advisor for the current plan details.
Des Moines air conditioning FAQ
What does cooling cost to add or replace?
Published Seattle-area ranges: about $7,377 for a central AC replacement (most between $5,098 and $9,785) and $2,222 to $5,555 for a single-zone ductless system (Angi, Seattle AC replacement costs, updated August 2026; Angi, Seattle mini-split costs, 2026 data). Our quote is written and specific to your home.
What is the best way to cool a condo near the marina?
Usually a ductless mini-split: one quiet indoor head in the main room, sometimes a second in the bedroom, and a small outdoor unit where the HOA allows it. It replaces the wall heaters for heating too.
Heat pump or central AC?
For most Des Moines homes, yes. It cools on hot days and heats the rest of the year, and PSE rebates apply when it replaces electric heat or pairs with a gas furnace (PSE electric resistance to heat pump rebate; PSE hybrid heat pump rebate). Central AC by itself does not qualify.
My AC runs but the house stays warm. What is wrong?
Check the filter first. After that the usual suspects are a dirty outdoor coil, a dead capacitor or a refrigerant leak. Ice on the copper lines means shut it off and call.
Do I need a permit for air conditioning in Des Moines?
Usually a mechanical permit and an electrical permit, both from the City of Des Moines through MyPermits Online (City of Des Moines, permit applications and information). We pull them and book the inspections.
How long does an install take?
Adding a coil and outdoor unit to an existing furnace is usually a one-day job. Ductless systems take one to two days depending on the number of indoor heads.
What warranty comes with your work?
We support the manufacturer’s warranty on covered equipment parts, and our labor warranty covers installations for 1 year from installation. Home Comfort Club members (monthly membership starting at $15 a month) with a new system installed by Home Comfort Alliance get extended labor coverage for as long as their membership stays active, up to 5 years from installation.
Why Choose Home Comfort Alliance in Des Moines?
Your Comfort is Our Promise
We promise...
Reliable heating, air conditioning, plumbing and electrical service, all from one trusted company.
To educate and guide you through your options so you’ll find the right solution at the right price.
Knowledgeable and respectful workers who ensure both your own comfort during the installation process, and lasting comfort from your home systems.
Outstanding service, communication, and follow-up, so your home is comfortable now and for years to come.
Get a cooling estimate in Des Moines
A Sumner-based comfort advisor will measure your home and give you written options, incentive help and financing choices.
Get an estimate
A Sumner-based comfort advisor will call you to set up your visit.