Ductless Mini-Split Installation & Service

Whisper-quiet, room-by-room cooling and heating for additions, sunrooms, garages, and homes without ductwork. Mitsubishi, Daikin, Fujitsu, LG & Samsung.

  • Single & multi-zone systems
  • Up to $2,000 in rebates
  • 12-year parts warranty
  • As quiet as 19 dB

Ductless Mini-Splits

No ducts? No problem. Room-by-room comfort, on demand.

Mini-splits skip the ductwork entirely. A small outdoor unit connects to one or more wall-, ceiling-, or floor-mounted indoor heads through a thin refrigerant line — no large air handler, no ducts to leak, no hot or cold rooms. Each indoor zone has its own thermostat, so different rooms can run at different temperatures.

We’re factory-trained on every major mini-split brand: Mitsubishi, Daikin, Fujitsu, LG, and Samsung. Modern cold-climate models heat down to -15°F and cool down to triple-digit summer days — making them a true year-round solution for additions, garages, sunrooms, and whole homes without ducts.

  • Zone-by-zone control Different temperatures in different rooms — without the cost of a zoned ducted system.
  • Quietly efficient Indoor heads as quiet as 19 dB — quieter than a whispered conversation.
  • Year-round comfort Cooling in summer, heating in winter — one system, one install.
  • Long warranty Up to 12 years parts + 2 years Mainstream labor on every install.

When Mini-Splits Make Sense

Common scenarios where mini-splits win

Mini-splits aren't the right answer for every home — but in these scenarios they almost always are:

  • No existing ductwork

    Older homes with hot-water heat or no central air — mini-splits add cooling without tearing into walls.

  • Additions or remodels

    Adding a room? A single-zone mini-split is cheaper and faster than extending the ductwork.

  • Hot or cold rooms

    Bonus rooms over a garage, sunrooms, third-floor bedrooms — mini-splits solve them.

  • Garage or shop

    Heat the workshop in winter and cool it in summer with a single dedicated unit.

  • Master bedroom too warm

    Add a single mini-split for sleep comfort without overcooling the rest of the house.

  • Want lower bills

    Inverter-driven mini-splits run 25–40% more efficient than older single-stage systems.

What We Install & Service

Single zone, multi-zone, and full-home

From a single bedroom unit to an 8-zone whole-home system — installed and serviced by factory-trained techs.

  • Single-zone systems One outdoor + one indoor head — perfect for additions and single-room comfort.
  • Multi-zone systems Up to 8 indoor heads off a single outdoor unit — independently controlled.
  • Cold-climate models Hyper-Heat and Heat-Pump Plus units rated to -15°F.
  • Whole-home conversions Replace baseboard or radiator heat with mini-splits + supplemental heating where needed.
  • Refrigerant line installs Properly sized line sets, vacuum testing, and EPA-compliant charging.
  • Wired & wireless controls Wireless remote, wall thermostat, smart-home integration — your choice.
  • Mini-split repair Indoor heads, outdoor units, line sets, and communicating controls.
  • Coil & blower cleaning Annual deep-cleaning service to keep efficiency and air quality high.

How It Works

A mini-split install, start to finish

Single-zone installs typically take a day. Multi-zone projects take 2–3 days.

  1. Free home assessment

    A comfort advisor reviews zone needs, line-set routing, and indoor-head placement options.

  2. Fixed-price quote

    System options, line-set runs, financing scenarios, and rebates — all in writing.

  3. Install

    Mount indoor heads, run line set, install outdoor unit, vacuum and charge. Single zone in a day.

  4. Walk-through

    Tech walks you through controls, modes, filter cleaning, and warranty registration.

Why Choose Mainstream

Same-Day Service

Most service calls handled same-day across Spokane and Coeur d'Alene.

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 room? Mini-splits fix it.

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

C Claudia Johnson
Claudia Johnson 4 hours ago
★★★★★
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.
S Sharon Scott
Sharon Scott 5 hours ago
★★★★★
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
S Steve Holding
Steve Holding 8 hours ago
★★★★★
Great work

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

Ductless Mini-Splits — Frequently Asked Questions

Will a mini-split actually heat in Spokane winters?

Yes — modern cold-climate mini-splits (Mitsubishi Hyper-Heat, Daikin AURORA, Fujitsu HSF) are rated to deliver 100% of their heating capacity at 5°F and continue working at -15°F. For most Spokane and Coeur d’Alene homes, that’s the entire winter.

How much does a mini-split cost?

Single-zone installs typically run $4,500–$8,000 depending on size and brand. Multi-zone systems scale based on the number of indoor heads and total tonnage. We quote fixed-price after the in-home assessment — no surprise add-ons.

Can a single outdoor unit serve multiple rooms?

Yes. Multi-zone systems support up to 8 indoor heads off a single outdoor unit. Each indoor head has its own thermostat and runs independently — you can heat one room, cool another, and turn off the rest.

Are mini-splits noisy?

No — they’re among the quietest HVAC equipment available. Indoor heads run as low as 19 dB (a whispered conversation is about 30 dB). Outdoor units are 50–60 dB at typical operation, similar to a quiet conversation.

What rebates are available?

Avista offers heat-pump rebates of up to $1,200 for qualifying mini-split systems. Federal Inflation Reduction Act tax credits provide 30% (up to $2,000) on heat-pump systems. We handle all the paperwork and confirm eligibility before you commit.

What's warrantied?

10–12 year manufacturer parts warranty (registration handled by us) plus a 2-year Mainstream labor warranty. Care Club members get extended labor coverage and priority service.

*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.

Ready when you are.

Same-day service across Spokane and Coeur d'Alene. Licensed in WA & ID, fully insured, satisfaction guaranteed.

(509) 237-6483 Book Now
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