The ducted vs ductless heat pump choice is about delivery, not technology. Clement Boston Heat Pumps installs ducted systems only, including attic air handlers and small-duct systems, so this is a comparison of how each one fits a Boston-area house, not a pitch for both.
The core difference
A ducted heat pump has one indoor air handler, hidden in a basement, attic or closet, feeding registers through ducts. A ductless system mounts a head on the wall of each room it heats, with refrigerant lines running to each one.
| Ducted heat pump | Ductless mini split | |
|---|---|---|
| Indoor equipment | One air handler per zone, out of sight | A wall or ceiling head in each room |
| Rooms served | Every room with a register | Rooms with a head; doors and walls block the rest |
| Filtration | A central filter, upgradeable | Small washable screens in each head |
| Efficiency rating | Lower on paper, from duct losses and fan power | Higher on paper, no ducts |
| Indoor sound | The air handler is remote; you hear air at registers | A quiet fan in the room |
| Best fit | Houses with ducts, or attics and basements for them | No room for ducts, additions, a few rooms |
| What we install | Yes | No |
Why ductless looks more efficient on paper
Ductless ratings skip a loss ducted systems have: heat leaking from ducts in cold attics and crawlspaces, plus fan energy spent pushing air through them. In a real house that loss depends on the ducts.
Closing the gap
Ducts inside the heated space lose almost nothing to the outdoors. Ducts in a cold attic need sealing and insulation, and sometimes a new route. We test static pressure and leakage at the first visit, and fix what we find on the estimate; see heat pump ductwork.
Our SEER2 and HSPF2 guide explains what the ratings measure.
Comfort and how heat reaches each room
A heat pump sized for the house only helps if the heat gets to the rooms. Ducts move it through every register; a wall head heats the room it’s in and relies on open doors for the rest.
Bedrooms, baths and closed doors
Closed bedroom doors, small baths and back rooms are where a few wall heads struggle. A ducted system with a return path in each room keeps them closer to the thermostat. Ductless solves that by adding heads, which adds cost and outdoor-unit capacity.
Sizing works differently
A ducted system is sized to the zone it serves, from a room-by-room load calculation, and the ducts split the heat by room. Ductless sizing happens head by head, and small rooms often end up with a head bigger than they need.
Why that matters in Massachusetts
Mass Save’s whole-home rebate expects the heat pumps to heat the whole home, which means every heated room needs a way to get heat. A ducted system reaches each room through its register.
A ductless plan reaches the same standard only with enough heads, and even the smallest heads can run oversized in a small bedroom, which leads to short cycles.
Upkeep
Both need the outdoor unit kept clear of snow and a yearly check. Ducted systems add one central filter to change; ductless systems add a screen and coil in every head to clean. Our maintenance service covers ducted systems.
Looks, space and the outdoor unit
Ducted equipment disappears into the house; the visible parts are registers and one outdoor unit per system. Ductless puts a white head on the wall of each room and runs line sets outside to it.
In a house with historic trim or a condo with rules about exterior lines, fewer visible parts matter. Back Bay, Beacon Hill and South End reviews look at what the street can see, so line sets running up a front facade are a problem either way.
Where ducted fits, and where it doesn’t
Most houses with a furnace, central AC or an open attic suit ducted. Houses with no basement, no attic and solid masonry walls may not.
- Furnace or central AC houses: reuse the ducts, often with a larger return; see replace AC with a heat pump.
- Boiler houses with attic and basement space: add ducts from both ends; see boiler to heat pump.
- Plaster walls and tight framing: small-duct high-velocity tubes fit where standard ducts won’t.
- A single addition or a sunroom: often a better fit for a wall unit.
The middle path for old houses
Small-duct high-velocity systems run 2-inch flexible tubes through wall and floor cavities to small round outlets. They give ducted delivery in houses that would otherwise need wall heads.
They cost more per ton than standard ducts and move air faster, with a soft hiss at the outlets. For triple-deckers and plaster-wall Victorians they’re often the best compromise; see heat pumps in older houses.
What the choice means for cost
Ducts set the price of a ducted job. Our typical range for a whole-home heat pump on ducts we can reuse is $15,000 to $28,000 and up before rebates; with new ductwork or a small-duct system, it’s $20,000 to $40,000 and up.
The cost guide breaks down what moves each figure. If your house leans ductless, we’ll say so at the first visit; if it suits ducts, we’ll measure them and price the job in writing.