Ductless vs ducted HVAC: which system fits your home?

Ductless vs ducted at a glance.

Prices are installed ranges from our estimator, reviewed August 2026.

What ducts do, and what they lose.

A ducted system uses one central unit (a furnace, an air handler, or a heat pump with an air handler) to make warm or cool air and pushes it through sheet metal or flex duct to registers in every room. ENERGY STAR estimates that about 20 to 30% of the air moving through a typical duct system is lost to leaks, holes and poorly connected ducts. The usual culprits:

• Leaky joints. Joints that were never sealed with mastic, or tape that has failed, leak conditioned air into the crawlspace or attic.
• Uninsulated runs. A metal duct through an unconditioned crawlspace or attic loses heat before the air reaches the room.
• Undersized trunks. Ducts sized for a smaller original furnace can't move the air a larger new system needs, which means noise and weak airflow.
• Too few returns. A single return can't keep every room balanced, so some rooms always run hotter or colder.

On the site walk we measure static pressure and check duct sizing and returns; a duct leakage test measures the leaks themselves.

What ductless does differently.

A ductless (mini-split, or non-ducted) system skips ducts entirely: one outdoor unit feeds one or more indoor heads on walls, in ceilings or near the floor through refrigerant lines, so no air travels through leaky ducts. ENERGY STAR describes ductless mini-splits as built for homes, or parts of homes, that have no ductwork.

Every indoor head has its own setting, so different rooms run at different temperatures. The heads are quiet: some Mitsubishi wall units are rated as low as 19 dB(A) on their quietest fan setting (see our heat pump noise guide).

When ductless is the better choice.

Ductless is the better choice when the ducts are leaky or missing, for an addition, ADU or garage, when rooms need different temperatures, when you want the highest efficiency, and when the home heats with electric baseboard today.

1. Your ducts are leaky, undersized or missing.

If a leakage test shows the ducts are losing a lot of air, or the trunks are too small for a modern system, you can fix the ducts or skip them. Fixing them can mean opening ceilings and crawlspaces, so get both options priced in writing before you decide. Homes that never had ducts (many older homes with electric baseboard) are the clearest case for ductless.

2. You're adding a room, an ADU, a garage or a shop.

Extending ductwork to a garage conversion, a finished basement or a detached ADU is expensive and often performs poorly. A single-zone mini-split is the usual answer.

3. Different rooms need different temperatures.

Upstairs bedrooms hot at night and the downstairs cold in the morning? Ductless puts each area on its own setting. Ducted systems can zone too, but with motorized dampers and a zone controller, which means more parts that can fail.

4. You want the highest efficiency available.

Single-zone ductless units carry the highest efficiency ratings we install: Mitsubishi's H2i sumo FX-Series is rated up to 35 SEER2, against 20.5 SEER2 for the American Standard AccuComfort Platinum 20, our top ducted heat pump.

5. Your home heats with electric baseboard or wall heaters.

Clark Public Utilities (Clark PUD) pays a flat $900 rebate for a ductless heat pump, single or multi-head, limit one per home, on a home that heats with electricity today, and any Washington-licensed contractor can file it. The ducted rebate requires an installer in Clark PUD's Contractor Network, which we have not joined. Details are in our Clark PUD rebate guide.

When ducted is the better choice.

Ducted is the better choice when your ducts test tight and are sized close to right, when you don't want visible heads on the walls, and when an open floor plan gains little from zoning.

1. You already have good ductwork.

If your ducts test tight and are sized close to right, replacing the central equipment is the fastest, cleanest upgrade, and it heats and cools every room from one system. A whole-house ductless retrofit would mean a head in every room for little gain.

2. You want HVAC you can't see.

Ductless heads are visible on the wall; registers in the floor or ceiling disappear. Ceiling-cassette and ducted mini-split heads exist, but they cost more and take more work to install.

3. You have a large, open floor plan.

An open main floor is one space with one temperature, so zoning adds little, and a ducted system with well-placed registers usually covers it more evenly than several wall heads.

4. You want a cold-climate heat pump but like your ducts.

The Mitsubishi SVZ air handler with a SUZ Hyper-Heat outdoor unit uses your existing ducts and keeps full heating capacity at 5°F.

Is ductless cheaper to run than ducted?

Ductless is often cheaper to run than ducted, but the ducts decide it. Both are heat pumps, so the difference in running cost comes from two places: duct losses and zoning. A ductless system has no duct losses, and you can turn off the rooms you aren't using. A ducted system with tight, insulated ducts inside the heated part of the house loses little, so the gap narrows. A ducted system with leaky ducts in a cold crawlspace can lose a large share of what it makes, which ENERGY STAR puts at about 20 to 30% of the air in a typical duct system.

If you heat with electric baseboard today, either kind of heat pump will cut your heating bill substantially; our heat pump cost guide has a savings calculator.

The hybrid answer.

A hybrid system keeps the ducted central system for the main living areas and adds a ductless head for the problem room, such as a bonus room over the garage, a finished basement, or a bedroom that's always hot.

Ducted vs ductless mini-split: the in-between option.

A ducted mini-split uses the same inverter heat pump as a ductless system, but the indoor unit is hidden in an attic, a ceiling or under the floor and feeds rooms through ducts instead of hanging on the wall. You get the mini-split's heat pump and zoning without a visible head; you give up some of the install simplicity.

Mitsubishi's ducted lineup includes these three:

• Low-static horizontal-ducted units heat and cool one or two rooms through a short duct run, mounted in the attic, in the ceiling, under the floor or behind a bulkhead. A concealed slim-duct head costs more per zone than a wall-mount.
• Mid-static horizontal-ducted units serve larger spaces or several rooms from a longer duct run.
• The SVZ multi-position air handler replaces a furnace on existing ductwork, installed horizontally or vertically, and pairs with a Hyper-Heat outdoor unit.

Mitsubishi's multi-zone outdoor units connect to up to eight indoor units, ducted or ductless, so one system can run a ducted unit over the bedrooms and a wall head in the living room. Two cautions: the ducts still need sealing and insulating, and Clark PUD's ductless rebate page describes single or multi-head systems without saying whether concealed ducted units count, so confirm with the utility before you count on the $900. See our ductless cost guide for pricing.

What a good quote should include.

If you're comparing quotes for ductless and ducted, make sure each one:

• Includes a Manual J load calculation, not a rule-of-thumb guess
• Names the outdoor unit, the indoor units and the AHRI-matched combination
• Shows the SEER2 and HSPF2 for the matched set, not just the outdoor unit
• Lists the permit fees separately
• If it keeps your ducts, says what condition they are in and what was tested
• Shows which rebates apply, and which installer files them

Want a number for your home first? The estimator shows the installed range for your home after a few quick questions and your contact details, and our ductless installation and heat pump installation pages show the equipment we install.

Questions homeowners ask.