Air Conditioning Buying Guide for Ontario Homes

Ontario summers are getting longer and more humid, and air conditioning has gone from a comfort upgrade to a health and safety feature for many households. If your central AC is ageing or you are adding cooling for the first time, the choices in 2026 look different than they did a few years ago: heat pumps have become a mainstream alternative, efficiency ratings changed, and refrigerants are in transition.

Your main options

Type	Typical installed cost (estimate)	Best for	Trade-offs
Central air conditioner	$5,000–$9,000	Homes with ducts and a working furnace	Cools only
Ducted heat pump (replaces central AC)	Somewhat more than central AC; cold-climate models $12,000–$25,000	Homes with ducts; furnace can stay as backup	Higher upfront; also heats
Ductless mini-split, single zone	$4,500–$8,000	Homes without ducts, additions, hot upstairs rooms	One room or area per indoor head
Window or portable AC	Low hundreds to about $1,000	Renters, single rooms, tight budgets	Noisier, less efficient (portables especially)

All costs are typical 2026 ranges, not quotes.

Should you buy a heat pump instead of AC?

A heat pump is an air conditioner that can also run in reverse to heat. In cooling mode they are equivalent. The questions are cost and benefit:

• Upfront: a basic heat pump may cost modestly more than a comparable AC. A cold-climate model that can carry most of your winter heating costs more.
• Rebates: central AC is not eligible for Home Renovation Savings rebates. A qualifying cold-climate air-source heat pump is: $500 per ton up to $2,000 in gas-heated homes, and $1,250 per ton up to $7,500 in homes with other primary heat, according to Save on Energy's mid-2026 figures. Participating contractor and pre-approval required; confirm on https://saveonenergy.ca (opens in a new tab).
• Heating flexibility: even if you keep your gas furnace, the heat pump can handle spring and fall heating. See our hybrid heating guide.

In many gas-heated homes, after the rebate, the difference between a good central AC and a cold-climate heat pump narrows to a few thousand dollars. It is worth getting quotes for both.

Efficiency ratings: SEER2 and EER2

Since 2023, cooling efficiency is rated with SEER2 (seasonal) and EER2 (at a fixed hot condition). These replaced the older SEER and EER numbers, and the test is tougher, so a SEER2 number is lower than the old SEER for the same equipment.

Rating	What it measures	What to look for
SEER2	Seasonal cooling efficiency	Higher is better; ENERGY STAR models exceed the minimum
EER2	Efficiency on a hot day	Important for peak-time costs
Variable-speed / inverter	Runs at partial output	Better humidity control, quieter, more efficient
ENERGY STAR	Certified efficiency level	Check at https://natural-resources.canada.ca (opens in a new tab) or https://www.energystar.gov (opens in a new tab)

How much does higher efficiency save? Ontario's cooling season is moderate, so a central AC might use roughly 1,000–2,500 kWh a year (estimate; varies widely with home size, insulation and thermostat habits). Moving from a minimum-efficiency unit to a high-efficiency one might cut that by 20–30%, which is often $50–$100 a year. Comfort and humidity control from a variable-speed unit are often the bigger benefits.

Sizing: bigger is not better

An oversized air conditioner cools the air quickly, satisfies the thermostat and shuts off before it has removed enough humidity. The result is a cold, clammy house, more on-off cycling and shorter equipment life.

Rules of thumb such as "one ton per 500 sq. ft." are unreliable. A proper cooling load calculation considers:

• Window area and orientation (west-facing glass adds a lot of heat in summer afternoons).
• Insulation and air leakage.
• Shading from trees and overhangs.
• Occupants and internal heat from appliances.
• Duct location and leakage.

If you are also thinking about a heat pump, the contractor should size for heating and cooling together. See our HVAC sizing guide.

The refrigerant transition

Federal HFC regulations are phasing down R-410A. New central ACs and heat pumps now use A2L refrigerants such as R-454B or R-32, which have much lower global warming potential.

What it means for you:

• If you replace only the outdoor unit, the indoor coil usually needs replacing as well; mixing refrigerants or mismatched components is not acceptable.
• Existing R-410A systems can still be serviced, but refrigerant prices may rise as supply tightens.
• Technicians must hold an ODP (Ozone Depletion Prevention) card to handle refrigerants, and A2L refrigerants have additional handling requirements. Ask about training.

Running costs and Ontario rate plans

In summer (1 May to 31 October), Time-of-Use on-peak is 18.9¢/kWh on weekdays from 11 a.m. to 5 p.m.; mid-peak is 14.6¢ from 7–11 a.m. and 5–7 p.m.; off-peak is 9.1¢ overnight and all weekend. These are commodity prices for 1 November 2026 to 31 October 2027 set by the OEB; delivery and other charges add to your bill.

Tip: Pre-cool the house a degree or two in the morning, then let the thermostat drift up slightly during on-peak hours. Close blinds on south- and west-facing windows. Our summer cooling savings guide has more ideas.

On Ultra-Low Overnight, on-peak is 37.7¢ from 4–9 p.m. on weekdays, which overlaps with hot late afternoons. ULO usually suits homes with EV charging or flexible loads more than heavy air conditioning. Compare with our electricity price plan calculator.

Buying checklist

• Get at least two or three written quotes with model numbers for both outdoor unit and indoor coil.
• Ask for a cooling (and heating, if heat pump) load calculation.
• Ask for an AHRI matched-system certificate or equivalent showing the rated SEER2 for the combination.
• Confirm the refrigerant type and the installer's handling certification.
• Confirm whether an ESA permit is needed for electrical work and who obtains it.
• Check the outdoor unit location: level pad, clearance, away from bedroom windows and the neighbour's property line, noise rating in decibels.
• Ask about a heat pump alternative and the rebate.
• Clarify warranty terms (parts vs labour) and registration.
• Do not sign anything at the door; unsolicited door-to-door contracts for air conditioners are banned in Ontario.

Our contractor guide has more questions to ask.

Frequently asked questions

How long does a central air conditioner last?

Typically about 12–20 years. Coastal corrosion is not an issue in Ontario, but units near dryer vents, under trees or with poor maintenance age faster. See our maintenance checklist.

Is it worth repairing an old R-22 air conditioner?

R-22 production has ended, so refrigerant repairs are expensive. If an R-22 unit needs a major refrigerant repair, replacement is usually the better choice.

Can I install a mini-split myself?

Some "DIY" kits are sold, but electrical work needs an ESA permit, and refrigerant handling requires certification. Warranties often require professional installation. We recommend a licensed installer.

Is a portable AC a good option?

Portable units with one hose are among the least efficient ways to cool a room, because they pull warm outdoor air in through gaps. A window unit or a ductless mini-split is usually better. See our ductless mini-split guide.