Heat Pump vs AC: Which One Fits Your Canadian Home?
A central air conditioner cools your home and nothing else. A heat pump cools just as well, then reverses to heat your home in winter. For most Canadian homeowners replacing an aging AC or planning to move off oil, gas or electric baseboards, the heat pump is the more versatile system. The air conditioner is the lower-cost choice when you already have a furnace you plan to keep.
Below we walk through how each works, what happens at minus 20, what the numbers look like, and the insulation and thermostat decisions that change the result more than most people expect.
TL;DR
An air conditioner only cools. A heat pump is fully reversible, so it heats and cools with one system.
Cold-climate air-source heat pumps are designed to work down to –30°C, though efficiency drops as it gets colder.
A heat pump costs more upfront than a central AC, but it can replace your heating system too.
Insulation, air sealing and a well-set thermostat decide how hard either system has to work.
Check current rebates and get an energy assessment before you sign a quote.
Table of Contents
How a heat pump and an air conditioner actually differ
Both machines move heat instead of making it. An air conditioner pulls heat out of your house and releases it outdoors. A heat pump does the same job in summer, but a reversing valve lets it run the other way, so it pumps heat into or out of the home depending on the season.
That is why the two look almost identical from the yard: an outdoor unit, an indoor coil, refrigerant lines between them. Natural Resources Canada notes that central air conditioners are cooling-only products, while heat pumps also provide winter heating. The same page states that a heat pump costs more than a central air conditioner, which in turn costs more than a room unit.
In practice, the question is rarely “which cools better.” It is “do I want my cooling system to also be my heating system?”
Heat pump vs AC at a glance
Central air conditioner | Air-source heat pump | |
Cools in summer | Yes | Yes |
Heats in winter | No | Yes |
Needs a separate heating system | Yes (furnace, boiler, baseboards) | Often no, sometimes backup heat |
Upfront cost | Lower | Higher |
Burns fossil fuel | No (the furnace does) | No |
Works with existing ductwork | Yes | Often yes |
Does a heat pump work in a Canadian winter?
Yes, with realistic expectations. Natural Resources Canada says a heat pump can heat when temperatures fall to –30°C and cool above 40°C. The City of Toronto adds that conventional units must switch to backup heating below about –15°C, while cold-climate models are built to keep going much lower.
The reason it works at all is that cold air still holds usable heat. NRCan explains that air at –18°C holds about 85% of the heat of air at 21°C. The catch is efficiency. NRCan reports that the coefficient of performance (COP) of air-source heat pumps typically runs from 2.0 to 5.4 at 8°C, but from 1.1 to 3.7 at –8°C. A COP of 3 means three units of heat delivered for each unit of electricity used.
For comparison, the Canada Home Electrification Toolkit lists seasonal efficiency (SCOP) for air-source heat pumps at 2.08 to 3.87, against 0.82 to 0.98 for fueled furnaces and boilers. Even at the low end of that range, a heat pump delivers more heat per unit of energy than a combustion appliance.
Backup heat and dual-fuel setups
In colder regions, a heat pump is often paired with extra heat. Carrier Canada notes that an electric heat strip can augment the indoor fan coil for enhanced heating capacity. Some homeowners keep the existing furnace as a backup in a dual-fuel arrangement, which lets the heat pump handle most of the season and the furnace cover the deepest cold snaps.
Do I still need an AC if I have a heat pump?
No. The heat pump is your air conditioner. One outdoor unit and one indoor coil handle both seasons, which is also one less machine to maintain and eventually replace.
If you already have ductwork, the swap is often simple. ENERGY STAR says these all-in-one systems use the same ductwork as a current central AC or furnace, so no additional renovations or electrical upgrades are required for installation in the typical case, and that replacing an older central AC with a certified heat pump could save nearly US$600 over the life of the product on cooling costs alone. That is a US figure, so treat it as a sense of scale rather than an Ontario quote.
If your ducts have had moisture trouble, deal with that before any new equipment goes in. Guidance on mold in HVAC systems explains what to do in the first hours and days after you find it, and it matters whichever system you choose, since both heat pumps and air conditioners share the same duct network.
Why is my bill so high with a heat pump?
Three causes come up most often.
You replaced cheap gas heat. Renovate.com notes that electricity bills may rise when a heat pump replaces a cheap natural-gas furnace, because you move part of your heating from one fuel to another. Your gas bill should fall, so compare totals rather than the hydro bill alone.
Deep cold. Trane explains that near freezing and below, standard heat pumps have to work harder to bring heat into the home, and backup electric heat is far less efficient than the heat pump itself.
Heat is leaving the house. A leaky attic or thin walls make any system run longer. This is the most fixable cause, and the next sections cover it.
On the electricity side, our guide to cutting your Ontario hydro bill covers the rebate and credits that apply to Ontario households.
What does each system cost?
Exact prices depend on your home, ductwork, electrical panel and the system size, so get written quotes. Two published reference points help with planning:
NRCan’s ranking is consistent: room AC, then central AC, then heat pump, from lowest to highest cost.
In the US, Renovate.com reports whole-home heat pump systems between US$17,000 and US$23,000, with smaller ductless systems starting around US$10,000 before rebates. Canadian pricing differs, so use this only to understand the relative scale.
A useful way to compare is total cost of ownership. A central AC plus a furnace means two systems to buy, service and replace. A heat pump may let you retire both. For a side-by-side look at upfront cost, operating cost and savings when upgrading residential HVAC, this overview of HVAC upgrade savings and costs is a helpful companion, though keep in mind it describes a warmer climate than ours.
Before you commit, see our rundown of heat pump rebates in Ontario and how the $600 assessment rebate helps you lock in energy incentives. Programs change, so confirm the current terms on the official program pages.
Ducted, ductless or room unit?
Central ducted. Best when you already have good ductwork. A heat pump here replaces the central AC and can take over from the furnace.
Ductless mini split. A wall-mounted indoor head connects to an outdoor unit with no ducts. It suits additions, older homes with radiators or baseboards, and rooms that never feel comfortable. A mini split is a heat pump, so it also heats. Multiple heads let you set different temperatures by room.
Room air conditioner. The cheapest to buy and cooling only. It suits a single bedroom or an apartment where you cannot modify the building.
The choice comes down to what you have now. Ducts in good shape point to ducted. No ducts point to ductless. A single hot room points to a room unit or one mini split head.
Fix the envelope first: insulation compared
The Canada Home Electrification Toolkit makes a point that is easy to miss: heat pumps and fossil systems alike work with the building envelope, and significant envelope upgrades may allow a smaller, less expensive heating system. The same document notes that often big improvements come from simple measures like sealing leaks around vent pipes, replacing weatherstripping and adding attic insulation.
Cellulose vs fiberglass
Both are blown into attics and walls and both perform well when installed properly. A few differences matter:
R-value. For a 2x4 wall, NAIMA Canada shows blown-in cellulose at R-12 to R-13 and blown-in fiberglass at R-12 to R-14.
Settling. NAIMA states dry loose-fill cellulose can settle up to 20% in attics, while blown-in fiberglass sees virtually none. RenoHouse puts cellulose settling at 10 to 15% and loose-fill fiberglass at 2 to 5%. Installers account for settling when they set depth.
Gaps. NRCan notes cellulose’s small particle size lets it fill gaps around nails and wiring, though blowing it creates a lot of dust.
Cost. RenoHouse lists Toronto attic prices of $1.20 to $1.60 per square foot for blown cellulose and $1.40 to $1.80 for loose-fill fiberglass.
Blown-in vs batt
Net 0 Homes describes blown-in as a common Canadian attic retrofit solution, quick to install and good around obstacles, while batts suit unfinished spaces during construction. Advance Insulation adds that blown-in costs more upfront because of equipment and labor, but fills cracks and gaps completely, which suits older homes with irregular spaces. For existing walls, NRCan says contractors can dense-pack loose fill through one to five drilled holes per storey.
Spray foam vs rockwool vs cellulose
Material | Typical strength | Reference cost |
Cellulose | Low cost, fills gaps, tolerates occasional wetting | |
Rockwool | Fire resistant, handles moisture well | |
Closed-cell spray foam | High R-value per inch, water resistant |
The City of Calgary notes that mineral wool is the most fire resistant and spray foam the most water resistant. Spray foam brings a higher R-value per inch and air sealing in one step. Rockwool and cellulose bring lower cost and forgiving moisture behavior. Ontario Building Code requirements, such as a thermal barrier over spray foam, apply, so a licensed insulation contractor should confirm what suits your assembly.
Whichever you choose, get the air sealing done first. A professional energy assessment shows where heat escapes. Our guides to the difference between an energy audit and an assessment and the cost of a home energy audit in Ontario explain what you will get and what you will pay.
Smart vs programmable thermostats
A programmable thermostat follows a schedule you set. A smart or Wi-Fi thermostat also lets you adjust from your phone and can learn your routine. Either one saves energy if you use it, and the biggest gain comes from the setpoints.
NRCan’s ENERGY STAR page recommends programming 17°C when sleeping or away and 20°C when awake and home, and says lowering the temperature two to three degrees is optimal for saving energy while staying comfortable.
With a heat pump, ask your installer how deep a setback to use. Big overnight setbacks can trigger backup electric heat in the morning on some systems, which cancels the savings. Many homeowners get better results from smaller, steadier adjustments. Also confirm that a thermostat is compatible with your equipment before you buy one.
Our perspective
In our work moving families in and out of homes across Niagara, Hamilton and London, we see the same pattern. People hold off on comfort upgrades because the house is in disarray, and then pay more for a system that has to work around a drafty, cluttered, poorly set-up home. We think of a heat pump decision as a whole-home project. Get the assessment, seal and insulate, choose the system, and make the space ready for the crew. Clear access to the basement, the mechanical room and the yard for the outdoor unit is half of a smooth install day. That is where we help. We offer itemized and flat-rate pricing, so you know what a service costs before we start, and our decluttering, delivery and assembly services are built for the busy households that tend to be mid-upgrade. Our Space Reset and Inhome Refresh services help you get areas ready, and Lawn Refresh helps tidy the area around outdoor equipment. Natalie
Get the house ready for the upgrade
Whether you install a heat pump, add attic insulation or replace a thermostat, the work goes faster and costs less in labor time when the crew can reach what they need. We can help with that part.
Space Reset, $75. We help clear and organize a room, basement corner or utility area.
Inhome Refresh, $65. A refresh of the spaces inside your home.
Lawn Refresh, $65. A tidy yard so the outdoor unit location is accessible.
Inhouse Delivery, $125. We move bulky items from one room to another, or bring large purchases inside.
The ATLAS PASS is $312 per year if you expect to need our services more than once. You can see every service and book online in a few minutes.
If an upgrade is part of a bigger plan, such as moving in winter, our winter moving guide explains why a one-day buffer helps. For planning the landscaping side, read how energy-smart landscaping can cut cooling bills.
Which should you choose?
Your AC is failing and your furnace is fairly new. A new central AC or a heat pump both make sense. The heat pump gives you heating backup options and lower fossil fuel use.
Both your AC and furnace are old. A heat pump, possibly with backup heat, is the strongest candidate, because you can replace two systems with one.
You heat with oil, propane or electric baseboards. A heat pump is typically the biggest efficiency change you can make.
No ducts. A ductless mini split heat pump.
One hot room. A room AC or a single mini split head.
In each case, insulate and air seal first when the assessment says to.
FAQ
What are the disadvantages of heat pumps?
The common ones are a higher upfront cost than a central AC, more complex installation, and lower efficiency in extreme cold, where supplemental heat is often needed. You also need outdoor space for the unit and regular upkeep. Choosing a cold-climate model and sizing it correctly addresses most of these.
Do I need an AC unit if I have a heat pump?
No. A heat pump cools in summer by running the same cycle as an air conditioner, so one system covers both seasons. Some homes keep a furnace or add electric heat strips for the coldest days.
What is the $5000 rule for AC?
It is a rule of thumb: multiply the unit’s age by the repair quote, and if the result passes $5,000, replace it instead of repairing. It is not an official standard. If you are replacing, compare a heat pump quote alongside a central AC quote.
Can a heat pump work with my existing ducts?
Often yes. ENERGY STAR says a heat pump uses the same ductwork as a central AC or furnace. A contractor should check that the ducts are sealed and sized for the new system.
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