Room-by-Room Comfort — No Ductwork Required
Mini-splits heat and cool the rooms your central system can't reach — quietly, efficiently, and with independent control in every zone. We design each system around your home and explain your options in plain language.
Room-by-Room Comfort — No Ductwork Required
Some rooms just never get comfortable. A converted garage, a bonus room over the garage, an addition, an ADU, or that one bedroom that's always too hot or too cold. Running new ductwork to reach them is expensive and disruptive. A ductless mini-split solves the problem without tearing into your home.
A mini-split delivers both heating and cooling from one system, runs quietly, and lets you set the temperature independently in each room. At Coast, we design the system around the rooms you actually want to condition — no oversized equipment, no confusing sales pitch, and a single upfront price before any work begins.
A System Designed Around Your Rooms
A mini-split isn't one-size-fits-all. The rooms you want to condition, their insulation, sun exposure, layout, and how you use the space all shape how many indoor heads you need and how large each one should be.
Installing a head that is larger than a room needs doesn't mean better comfort. An oversized zone short-cycles, struggles to control humidity, and wastes energy — while an undersized one can't keep up when temperatures swing.
That's why Coast starts with the rooms — not the equipment catalog. We evaluate your space and determine the zone layout, capacity, and head style that fit how you live.
Ready to move forward?
0% financing for 12 months on qualifying systems — View financing options →
Is Ductless the Right Fit? We'll Tell You Straight.
Ductless isn't the answer for every situation. If your home already has good ductwork and a central system that reaches every room, a mini-split may not be the most cost-effective path. But when you have rooms with no ducts, an addition or ADU that needs its own comfort, or hot-and-cold spots the central system can't fix, ductless is often the better long-term decision.
We'll look at your home, explain what we find, and walk you through your options — what a ductless system would look like and how it compares to the alternatives — before you decide anything.
Our job is to give you the information. The decision stays yours.
Signs a Ductless Mini-Split Makes Sense
Not sure whether ductless is right for your home? One of these alone doesn't settle it — but if several sound familiar, a mini-split is worth a serious look compared with extending ductwork or living with the rooms you have.
Sound like your home? We'll give you an honest assessment — free.
(206) 920-5547Choosing the Right Ductless System
There are a lot of ways to configure a mini-split. You shouldn't have to become an HVAC expert just to choose one. We simplify the decision by focusing on what actually matters for your rooms — and explaining the tradeoffs in plain language so you can compare options confidently.
Single vs. Multi-Zone
A single-zone system pairs one outdoor unit with one indoor head — great for one room. Multi-zone runs several indoor heads off one outdoor unit, each with its own control. We help you match the setup to how you actually use your space.
Head Styles
Wall-mounted heads are the most common and cost-effective. Ceiling cassette and low-wall units are options when a wall mount won't work for the room. We walk through placement so each head looks and performs right.
Sizing Per Zone
Each zone gets its own load calculation — not a one-size-fits-all guess. A head that's too large short-cycles and wastes energy; too small and it can't keep up. We size each room to the room.
Cold-Climate Performance
Modern cold-climate mini-splits hold full heating output well below freezing and keep running when temperatures drop further. We'll confirm the model you're considering handles Pacific Northwest winters.
What Happens During a Ductless Install?
A professional install should feel organized from the moment we arrive. Here's exactly what to expect — no mystery, no vague “we'll figure it out when we get there.”
Assess Your Home
We look at the rooms you want to condition, insulation, layout, and electrical panel so we can recommend a system that actually fits — not just sell you equipment.
Design Your Zones
We map out how many indoor heads you need, where each one goes, and how they connect back to the outdoor unit for balanced comfort in every room.
Mount & Run the Line Set
We mount each indoor head and set the outdoor unit, then run the refrigerant line set, drain, and wiring through a small, tidy penetration — no bulky ductwork required.
Complete the Electrical
We handle the dedicated circuit and disconnect the system needs, keeping everything to code and safe for your panel.
Commission the System
We vacuum and charge the refrigerant lines, power up each zone, and verify heating, cooling, airflow, and drainage before we call it done.
Walk You Through It
We show you how to run each zone from the remote or app, cover filter cleaning and upkeep, and answer your questions before we leave.
You shouldn't be left staring at a new remote wondering what happens next.
Ready to move forward?
0% financing for 12 months on qualifying systems — View financing options →
Why Proper Ductless Installation Matters
The equipment is only part of the equation. Even the best mini-split needs to be installed and commissioned correctly to perform the way it was designed to.
A properly evacuated line set, an accurate refrigerant charge, correct head placement, clean drainage, and a code-compliant electrical connection all determine how quiet, efficient, and reliable your system is. Cutting corners during installation undermines the investment you just made.
Quiet, Efficient Comfort in Every Room
A well-designed ductless system delivers steady heating and cooling, independent control in each zone, and noticeably quieter operation than window units or older equipment — often with lower energy use, since there's no duct loss.
It also gives you comfort in the rooms that never had it — and that matters whether you're heating through a Pacific Northwest winter or cooling during a summer heat wave.
Need help with the upfront cost? Financing is available →
Why Homeowners Choose Coast HVAC
HVAC service should be simple. You should be able to call, get a clear explanation, understand your options, and feel confident about the work being done in your home.
FAQs
Available Across South King County
Based in Kent and serving every city around it — same pricing, same response, wherever you are.
Heat and Cool Any Room Without Ductwork
Mini-splits are the ideal solution for additions, garages, and older homes. We'll assess your rooms, explain your options honestly, and install the right system at a price you knew upfront.
