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Ducted vs Ductless Heat Pump in Ontario: Which One When, With Existing Ducts, No Ducts, Radiant Floors and Closed Bedrooms, and What Each Costs
Heating, Cooling & Ventilation
Ducted or Ductless: The House Usually Decides Before You Do, and Here Is How to Read It
Most of the ducted-versus-ductless argument settles itself the moment someone looks in the basement. A house with decent ducts and a furnace gets a ducted heat pump, nearly always. A house with baseboards or a boiler and no ducts gets heads on the walls, unless it is getting a major renovation that opens the ceilings anyway. The hard cases are in between: the radiant floor house that needs cooling, the 1950s storey-and-a-half with bedrooms tucked under the roof, and the addition on a house that already has heat. This page goes through each with October 2026 numbers.
The House, the Choice, the Price
| The house you have | Usually the answer | Ducted, installed | Ductless, installed |
|---|---|---|---|
| Furnace and good ducts | Ducted, on the existing ducts | $9,000 to $18,000, default $13,000 | $8,000 to $17,000 for 2 to 4 heads |
| Baseboard or boiler, finished, no ducts | Ductless | $15,000 to $25,000 with full new ductwork | $12,000 default multi-zone |
| Gutting the house anyway | Either; ducts are cheap with ceilings open | $15,000 to $25,000 | $8,000 to $17,000 |
| Radiant floors, needs cooling | Ductless heads, or a small ducted air handler | quoted per house | $3,500 to $8,000 a head |
| One addition or a bonus room | One ductless head | extending ducts, if they reach | $3,500 to $8,000, default $5,500 |
Each ducted line is taken apart on the heat pump cost page, each ductless line on the mini-split cost page. New ductwork alone in a finished house runs $5,000 to $9,000 partial and $9,000 to $12,000 and up for a full retrofit; the ductwork cost page has the detail.
Why Ontario prices are all over the map: the contractors and price guides we checked for this page gave wildly different numbers for the same ductless job. For a multi-zone system, one national guide said $6,000 to $12,000 for 2 to 4 heads, a heat pump price guide said $8,000 to $16,000 and up, and a mini-split retailer said $14,000 to $22,000 for a 3-zone whole-home system. Ducted quotes spread just as far. Some prices include the electrical, the line set covers, the condensate and the old-unit removal; some leave them for later. Some are planned September installs and some are January emergencies. Budget $13,000 ducted on good ducts or $12,000 for a multi-zone, and get two or three quotes on the same written scope.
Existing Ducts: Use Them, After Someone Checks Them
If the house has a furnace and the ducts reach every room, a ducted heat pump uses what is already paid for. One outdoor unit, a coil on the furnace or a new air handler, one thermostat, and the whole house heats, cools and filters together. It costs about what a 3 or 4 head multi-zone does and covers every room, including the ones nobody would put a head in.
The catch is the ducts. A heat pump delivers air a little cooler than a gas furnace does, and it wants more airflow to move the same heat. Ducts sized for a 1990s furnace, with one return in the hall and undersized runs to the far bedrooms, can choke a heat pump. A good installer measures static pressure before he quotes and tells you if a return or two needs adding. If nobody measures anything, that tells you something as well.
No Ducts: Heads on the Wall, Mostly
Putting ducts into a finished house means opening ceilings, building bulkheads and losing closets, and $15,000 to $25,000 for the heat pump and ductwork together is the honest number. Ductless avoids all of it. The trade is that each head looks after its own room and a little more, so a house with closed bedrooms needs a head in each of them, and five heads is no longer cheap.
The line I draw: if the house opens up on the main floor and has three or fewer rooms that need their own head, ductless. If it has six closed rooms on two floors and you are renovating anyway, price the ducts. Somewhere in the middle are ceiling cassettes and small concealed ducted units that serve two or three rooms from one hidden air handler; they are quoted per house and worth asking about.
Radiant Floor Houses: A Different Question Altogether
A radiant floor heats. It does not cool, ventilate or dehumidify, and no amount of wishing turns warm concrete into air conditioning. Every radiant house we build gets an HRV and a cooling plan, and the cooling plan is ductless heads, a small ducted air handler, or fan coils. For most of our ICF houses, with their small cooling loads, one or two ductless heads on the main floor carry the summer, and the HRV moves the air around.
The ventilating a radiant house page covers the HRV and cooling design in detail, and radiant floor cooling explains why running cold water through the slab is not the shortcut it looks like. The houses themselves are at ICFhome.ca.
Comfort, Noise and Filtration, Side by Side
- Comfort. Ducted gives you even temperatures in every room the ducts reach, if the ducts are right. Ductless gives you very even temperatures in the rooms with heads and whatever drifts to the rest.
- Noise. A good indoor head on low is about as loud as a fridge. A ducted air handler sits in the basement and you hear the air at the registers. Outdoor units are similar; put either one away from the bedroom window and the neighbour’s deck.
- Filtration. Ducted wins. A furnace or air handler takes a deep media filter for the whole house. A head has a washable mesh screen that you have to clean every few weeks in heavy use, and most people do not.
- Fresh air. Neither one ventilates. A tight house needs an HRV or ERV either way; the HRV vs ERV page has the choice.
- Looks. Ducted is invisible. Heads are white boxes high on the wall. Some people do not care, and some spouses care a great deal.
Questions people ask
Is ducted or ductless better for an Ontario house?
With a furnace and good ducts already there, ducted, nearly always: it covers every room, filters better and costs about the same as a 3 or 4 head ductless system. With no ducts in a finished house, ductless, because new ductwork with the heat pump runs $15,000 to $25,000.
Can my old ducts handle a heat pump?
Often, but not always. A heat pump wants more airflow than a gas furnace. Ask the installer to measure static pressure and check the returns before quoting; undersized returns are the usual problem and the fix is usually a return or two, not a whole new system.
Do I need a head in every bedroom?
If you want the room comfortable with the door shut, yes. A head in the hall or the living room does not heat a closed bedroom in January. Size each head from a room-by-room heat loss; bedrooms usually want the smallest head made.
What cooling works in a house with radiant floors?
Ductless heads, a small ducted air handler, or fan coils. In a tight ICF house one or two heads on the main floor usually carry the summer. The house also needs an HRV, because the floor does not ventilate.
See both options priced on your house
The HVAC system cost comparison calculator prices the same house as a ducted heat pump, dual fuel, or gas combi with radiant and ductless cooling, installed and over 15 years. If you have one ducted quote and one ductless quote and they look like apples and oranges, the $99 review lines them up.
Sources and further reading
- Heating and Cooling With a Heat Pump: Natural Resources Canada: how air-source, ductless, ground-source and air-to-water heat pumps work in a Canadian climate, sizing, backup heat and balance points.
- OntarioHeatLoss.ca: the CSA F280 room-by-room heat loss and the HVAC design and drawings a permit needs, and the number every piece of equipment should be sized from.
- What is a heat or energy recovery ventilator and why do I need one?: Natural Resources Canada: HRVs and ERVs in plain language, and why an airtight house needs one.
