Wall-mounted head
The most common and the least costly per room. Mounted high on an exterior wall, with the lines running out behind it. It is visible and needs clear wall space near the ceiling.
Ductless mini-splits, for houses that were never built for ductwork.
A ductless system heats and cools room by room through a thin line set and one small opening in the wall. For a house heated by radiators or baseboard, it is usually the cleanest way to add heat pumps and air conditioning at the same time.
How a ductless system works
An outdoor unit sits on a stand or wall bracket beside the house. Inside, one or more indoor units hang on the wall, sit on the floor or fit into the ceiling of the rooms that need them. Each indoor unit is connected to the outdoor unit by a line set: two copper refrigerant lines, a condensate drain and a low-voltage communication cable, bundled together and passed through a single three-inch opening in an exterior wall.
In winter the outdoor unit draws heat from the outside air and sends it indoors; in summer it runs in reverse. The compressor is inverter-driven, so instead of switching fully on and off it slows down and speeds up to match the heat the room is losing. That is why a well-sized ductless system runs quietly for long stretches and keeps the temperature steady, rather than cycling between too warm and too cool.
Every indoor unit has its own controls, so each room or zone is set separately.
Indoor units
Four kinds of indoor unit, chosen room by room
A single outdoor unit can often drive a mix of them, so the choice can follow each room rather than the house.
Floor console
Sits low on the wall, often where a radiator used to be, and delivers heat at floor level. Suits kneewalls and rooms with little wall space up high. Fewer models are made.
Ceiling cassette
Recessed between ceiling joists so only a flush grille shows. Needs an accessible attic or unfinished space above, and the attic run must be insulated.
Concealed ducted
A compact air handler hidden in an attic, closet or soffit, with short ducts to grilles in two or three neighboring rooms. Only the grilles show.
Single-zone or multi-zone
There are two ways to connect indoor units to outdoor units, and many houses end up with a mix of both.
| Single-zone | Multi-zone | |
|---|---|---|
| Layout | One outdoor unit for each indoor unit. | One outdoor unit serving several indoor units. |
| Cold-weather performance | Each pair is matched to one room’s load, which generally gives the best efficiency and low-temperature output. | Capacity is shared between rooms; small rooms can be oversupplied when only they are calling for heat. |
| Outdoor equipment | More outdoor units on the house. | Fewer outdoor units, often only one. |
| Best suited to | Main living areas, rooms with large or very different loads. | Groups of smaller rooms such as bedrooms, and houses with limited space for outdoor units. |
Where the lines go
The route of each line set is planned at the assessment and written into the quote, so there are no surprises on installation day.
- Outside the house
- Lines usually drop down an exterior wall in a cover painted to match, run along corner boards and trim rather than across clapboards.
- Through the house
- Where the attic or basement gives a cleaner path, lines run there instead, within the manufacturer’s limits on length and rise.
- Condensate
- Drained by gravity where the house allows it, or by a quiet condensate pump where it does not, and discharged away from paths that freeze.
- The outdoor unit
- Set on a stand or wall bracket above expected snow depth, away from bedroom windows and property lines, with room to service it.
Is ductless right for your house?
Usually a good fit
- Heated by a boiler with radiators or baseboard
- No ductwork, or no room to add it
- Rooms that never quite get comfortable
- Window air conditioners you want to retire
- Additions, finished attics and bonus rooms
Worth comparing with other options
- The house already has well-sized, well-sealed ductwork: a ducted heat pump may serve it better
- You plan to keep the boiler for part of the heating: see heat pumps with your boiler
- Many small rooms off a hallway: a concealed ducted unit can serve several at once
How many indoor units will I need?
One for each room or group of rooms that needs its own control. The room-by-room load calculation decides it: open living and dining areas can often share a unit, while a bedroom over the garage usually needs its own.
Will the indoor units take up wall space?
A wall-mounted head sits high on the wall, above furniture. Where that does not suit a room, a floor console, ceiling cassette or concealed ducted unit can take its place.
How loud are they?
Indoor units on low are typically rated in the low 20s to low 30s dB(A); outdoor units are commonly in the 40s and 50s. Your quote lists the published rating for every unit we propose.
See what your rooms need
The assessment measures every room and ends with a written plan: which indoor unit goes where, how each line set runs, and what it costs before and after rebates.