Quick answer
This isn't really an equipment decision — it's an architecture decision. The right layout follows your house: what ducts exist, what condition they're in, which rooms are always the wrong temperature, and what got added after the original system went in. All three layouts can run on efficient heat pump equipment; the question is how the comfort gets delivered to each room.
- Ducted = one indoor unit, invisible delivery, one filter to change — if your ducts are good, it's hard to beat.
- Ductless = no ducts needed, room-by-room control, and no duct losses — but you'll see the heads on your walls.
- Mixed = ducted for the floors that have ducts, heads for the spaces that don't. Very Seattle.
- Duct condition decides more than equipment brochures do — leaky ducts can waste 20–30% of the air they carry (ENERGY STAR estimate).
Last updated: 2026-07-13 · Written & reviewed by the Eco field team
Ducted vs ductless vs mixed at a glance
| Ducted | Ductless (Mini-Split) | Mixed | |
|---|---|---|---|
| How air gets delivered | Hidden ducts to every room | A head unit in each zone | Ducts where they exist, heads where they don't |
| Visible in rooms? | Just registers | Wall/ceiling heads | Both, by area |
| Zoning | Whole-home (or added dampers) | Per head, built in | By area |
| Needs from your house | Good, right-sized ductwork | Wall/ceiling space + line-set routing | Depends on area |
| Best fit | Homes with sound existing ducts | No-duct homes, additions, ADUs | Homes with partial or aging duct coverage |
This is an architecture decision, not an equipment decision
The right layout follows your house: what ducts exist, what condition they're in, which rooms are always the wrong temperature, and what got added after the original system went in. All three layouts can run on efficient heat pump equipment; the question is how the comfort gets delivered to each room.
Why so many Seattle homes end up mixed
Our housing stock is the reason. A 1920s Craftsman with a basement furnace may have decent ducts for the main floor and nothing upstairs, where the attic became two bedrooms in 1978. A rambler with a 1990s addition often has ducts that were never extended. And plenty of older homes have no ducts at all — they grew up on radiators or wall heaters. National comparison guides assume you're choosing one layout for a blank-slate house; here, the honest answer is usually “ducted where the house cooperates, ductless where it doesn't.”
What each layout actually is
Ducted: one indoor unit (furnace or air handler) pushes conditioned air through a tree of supply ducts and pulls it back through returns. Done right, it's invisible, quiet, and filters your whole home's air at one point. Done wrong — leaky joints, crushed flex duct, uninsulated runs through a cold crawlspace — it quietly throws away a chunk of everything your equipment produces. Ductless: an outdoor heat pump feeds refrigerant lines directly to individual indoor heads, each conditioning its own zone with its own thermostat. No ducts means no duct losses and no need for duct space — which is exactly why ductless became the default answer for Seattle's older, duct-free housing stock. The tradeoff is visual (heads on walls) and per-zone cost. Mixed: one outdoor unit (or two) serving both a ducted air handler and ductless heads. The classic Puget Sound version: the main floor runs on the original ductwork, while the converted attic, the addition over the garage, or the basement ADU gets its own head.
Pros and cons, honestly
Ducted
Pros
- Invisible delivery — just registers in each room
- One central filter to change; whole-home air filtered at one point
- Hard to beat when existing ducts are sound and right-sized
Cons
- Comfort depends entirely on duct quality
- Real losses if ducts leak or run unsealed through crawlspaces
- Zoning requires added dampers
Ductless (mini-split)
Pros
- No ducts needed — and no duct losses
- Room-by-room control, built in
- The default answer for no-duct homes, additions, and ADUs
Cons
- Wall or ceiling heads are visible in each zone
- Every head is a small appliance — its own filter, condensate path, and service point
- Per-zone cost: every conditioned room needs a head or a shared solution
Mixed
Pros
- Ducts where they exist and work; heads where they don't
- Duct losses reduced — only where ducts serve
- Fits Puget Sound's partial-duct housing stock better than either pure layout
Cons
- Two delivery methods and one refrigerant system need thoughtful design
- Controls must not fight each other — installer skill shows here
The tradeoffs nobody puts in the brochure
Ductless heads are visible — most people stop noticing them in a month; some never do. If aesthetics matter, say so early: ceiling cassettes and slim ducted units exist for a price. Every ductless head is a small appliance with its own filter to wash, its own condensate path, its own service point — four heads means four of everything. And ducted comfort depends entirely on duct quality: a great heat pump on bad ducts is a great engine in a car with flat tires. Have the ducts inspected before anyone quotes equipment.
Mixed systems live or die on design
Two delivery methods, one refrigerant system, and controls that don't fight each other — this is where installer skill shows. A mixed layout designed room-by-room is the best of both; one assembled from a catalog is a service headache.
The verdict, by situation
Ducted
Hard to beat when the ducts are good
Invisible, quiet, one filter to change. But comfort depends entirely on duct quality — leaky ducts can waste 20–30% of the air they carry (ENERGY STAR), so inspect before anyone quotes equipment.
Ductless
The default for duct-free housing stock
No ducts, no duct losses, room-by-room control. The tradeoffs are visual (heads on walls) and per-zone cost — and every head is a small appliance with its own filter and service point.
Mixed
Very Seattle — and usually the honest answer
Ducted where the house cooperates, heads where it doesn't. It lives or dies on design: two delivery methods, one refrigerant system, and controls that don't fight each other.
Which Washington homes this fits
1920s Craftsman, attic converted in '78
The classic mixed case: main floor on the original ducts, a head for the attic bedrooms the ducts never reached.
Rambler with a 1990s addition
Additions often never got duct extensions — one head serves the addition without touching the working ducted core.
Older home on radiators or wall heaters
No ducts at all means ductless is the natural fit — no duct construction, zoning built in, and heat pump efficiency year-round.
Newer home with sound, right-sized ducts
Keep it ducted — one indoor unit and invisible delivery win when the architecture already cooperates.
How we build this guidance
- We install all three layouts across Seattle and Everett — including the mixed systems national guides skip.
- Layout recommendations start with a duct inspection and a room-by-room comfort conversation, not an equipment catalog.
- We'll tell you when your existing ducts are worth keeping — and when they're the real problem.
Methodology: Duct-loss figures from ENERGY STAR estimates for typical homes; layout guidance from field experience with Puget Sound housing stock.
Ready for the next step?
Get a free estimate for your actual house, not a hypothetical one — honest numbers and rebate eligibility checked before any work begins.
Continue exploring
- Learn: What is a ductless mini-split and when does it make sense? →
- Learn: Which systems fit your Seattle home? →
- Learn: How does ductwork work in your home? →
- Learn: Imbalanced heating & cooling — and a solution for it →
- Evaluate: Ducted heat pump vs ductless mini-split →
- Compare: Do I need to clean my ducts? →
- Compare: Heat pump vs air conditioner →
- Learn: Window AC vs mini-split for single rooms →
- Learn: When to replace the ductwork itself →
- Book: Home comfort estimates →
- Learn: All Heating & Air guides →
Common questions
Is ductless more efficient than ducted?
Head-to-head on paper, often slightly — no duct losses. In practice it depends on your ducts: tight, insulated ducts close the gap; leaky crawlspace ducts hand ductless the win. That's why we inspect before we recommend.
Do I need a head in every room?
No — and this is a common overquote. Open floor plans can share heads, small bedrooms can borrow from hallway units in mild weather, and mixed layouts can duct clusters of small rooms. The right count comes from a load calculation, not a per-room formula.
Can one outdoor unit run both ducts and heads?
Yes — multi-zone outdoor units can feed a ducted air handler and ductless heads at the same time. That's the backbone of most mixed systems.
My upstairs is always the wrong temperature. Which layout fixes that?
That's usually a delivery problem, not an equipment problem — and it's the classic case for adding a ductless head upstairs or rebalancing/upgrading the ducts. Whole-home replacement isn't always the answer; sometimes one head is.
What does each layout cost?
It varies too much by house to give honest flat numbers — duct condition, zone count, and electrical scope move the price more than equipment does. What we can promise: a line-item quote per layout, so you can compare the architectures directly for your home.
Sources & references
Equipment ratings, program details, and industry figures on this page come from manufacturers and primary sources, linked below. Verify program status and requirements for your home where applicable.
Ductless & duct systems
- Ductless mini-split heat pumps: how they work and where they fit — ENERGY STAR — Ductless Heating & Cooling
- In a typical house, 20–30% of duct air is lost to leaks, holes, and poor connections — ENERGY STAR — Duct Sealing
- Residential duct systems are sized to ACCA Manual D — ACCA — Manual D: Residential Duct Systems