Central Air Conditioning Cost in Ontario (2026): AC by Size, Existing Ducts vs New, SEER2, Why a Heat Pump Costs Less Extra Than You Think, the Electrical and What Moves the Price

Heating, Cooling & Ventilation

What Central Air Costs in Ontario, and Why the Better Question Now Is Whether to Buy an Air Conditioner at All

Central air on existing ducts is one of the simpler jobs in the trade: an outdoor condenser on a pad, a coil on top of the furnace, a line set between them and a charge of refrigerant. It is also the job where the quote you get in a July heat wave and the quote you get in October are two different animals. This page has the October 2026 installed ranges for Central Ontario by size, what new ducts add, what SEER2 means on the sticker, and the arithmetic on the heat pump that now sits beside every AC on the showroom floor.

Installed ranges, Central Ontario, checked October 2026, before HST. Researched ranges from Ontario and Canadian price guides and contractor pages, with the default the calculators use; not my subcontractor prices.

The numbers

$6,000central AC, 2 to 3 ton, existing ducts
$10,500furnace and AC together
$9,500standard heat pump in the same spot
$150 to $250annual service allowance
JobRangeDefault
Central AC, 2 to 3 ton, existing ducts$3,500 to $8,500$6,000
Central AC, 3 to 4 ton, 2,000 to 3,000 sq ft house$5,500 to $8,500
Central AC where new ductwork is needed$6,000 to $14,000
Furnace plus central AC together, existing ducts$6,500 to $12,500$10,500
Standard heat pump instead of the AC, on the furnace$7,000 to $12,000$9,500
Cold-climate heat pump instead of the AC$9,000 to $18,000$13,000
Dedicated 240 V circuit and disconnect, first-time AC$500 to $1,500
Duct modification$300 to $1,500

Furnaces are on the furnace replacement cost page; heat pumps in every form are on the heat pump cost page.

Why Ontario prices are all over the map: the contractors and price guides we checked for this page quoted very different prices for the same air conditioner. A home-services marketplace said $3,500 to $7,000 with existing ducts and $6,000 to $14,000 when ducts are needed; the published Ontario range we use runs to $8,500 on existing ducts. The low end is usually a basic single-stage unit swapped onto a coil and line set that are reused; the high end is a variable-speed unit with a new coil, new lines, a new pad and the old unit hauled away. Who is quoting matters, and so does the week: a heat wave adds to every price. Budget $6,000 on existing ducts, and get two or three quotes on the same written scope.

What Moves the Price

The size. A ton of cooling is 12,000 BTU/h. Most 2,000 sq ft Ontario houses on existing ducts end up between 2 and 3 tons, and a tight one needs less than the square footage suggests. Size it from a heat gain calculation, not the old unit’s nameplate; the sizing mistakes page explains why an oversized AC leaves the house cold and clammy at the same time.

The coil and line set. A new condenser on the old indoor coil and old copper is the cheap quote. A matched coil and new lines cost more and are usually what the manufacturer’s warranty assumes. Ask which one you are getting, in writing.

Single-stage or variable-speed. A single-stage unit is on or off, like a light switch. A two-stage or variable-speed unit runs low and long, which pulls more moisture out of the air and is quieter. The price gap is real and so is the comfort gap on a muggy Georgian Bay July night.

The ducts. A house heated by a boiler or baseboard has no ducts, and $6,000 to $14,000 is the AC with new ductwork. At that number, ductless heads deserve a look; see ducted vs ductless.

SEER2, in Plain English

SEER2 is the seasonal cooling efficiency on the yellow sticker, tested to a newer procedure that pushes air through a duct system more like a real house’s. The numbers came out lower than the old SEER for the same machine, so a SEER2 rating and an old SEER rating are not comparable, and a salesman comparing your old unit’s SEER with a new one’s SEER2 is comparing a ruler with a tape measure. Higher is better; compare SEER2 to SEER2 between quotes, and look at the noise rating while you are on the sheet.

In most of Simcoe County the cooling season is short, so the jump from a good SEER2 to the very top rarely pays back on hydro alone. What does pay back is a correctly sized unit with a matched coil, installed by someone who weighs in the charge rather than guessing it.

Why a Heat Pump Costs Less Extra Than You Think

A heat pump is an air conditioner with a reversing valve and better controls. It cools exactly the same way and then heats the house in the fall and spring. On the defaults: a 3 ton AC at $6,000 is $6,780 with HST; a standard heat pump in the same spot at $9,500 is $10,735 with HST. The difference is $3,955 with tax, for a machine that also heats. A cold-climate unit at $13,000 is $14,690 with HST, $7,910 more than the AC, and in an Enbridge gas-heated home it can qualify for up to $500 per ton, $1,500 at 3 tons, if the model is on the NRCan list and a participating contractor gets pre-approval first. Check the program site before you sign.

If the AC is dead and the furnace is young, I would at least price the heat pump. If the AC is dead and the furnace is twenty, read the dual fuel page before you buy either.

Who Can Install It

  1. Refrigerant work is a licensed trade. The mechanic holds a 313A Refrigeration and Air Conditioning Systems Mechanic or 313D Residential Air Conditioning Systems Mechanic certificate, is on the Skilled Trades Ontario public register, and carries an ODP card. The ODP card alone does not allow work on the equipment.
  2. No one vents refrigerant. The old unit’s charge is recovered, not let go into the yard.
  3. The electrical for hire is an ESA licensed electrical contractor with a permit. A first-time AC needs a new 240 V circuit and disconnect.
  4. If the furnace is touched, a TSSA-registered contractor with a certified gas technician does it.
  5. Nobody sells you an air conditioner at your door. Since March 1, 2018, a contract signed at your home for an air conditioner that you did not ask for is void. The licensing page shows how to check each card.

Questions people ask

How much does central air cost in Ontario in 2026?

Installed and before HST, $3,500 to $8,500 for a 2 to 3 ton unit on existing ducts, about $6,000 as a default; $5,500 to $8,500 for 3 to 4 tons in a 2,000 to 3,000 sq ft house; $6,000 to $14,000 when new ductwork is needed.

What size air conditioner does a 2,000 sq ft house need?

Usually 2 to 3 tons, and less in a tight house. The real answer comes from a heat gain calculation, not the square footage or the old unit. An oversized AC short-cycles and leaves the house damp.

Should I buy a heat pump instead of an AC?

Price both. On the defaults a standard heat pump is about $3,955 more than a 3 ton AC with HST and also heats the house in mild weather. A cold-climate unit costs more again but can qualify for a rebate in a gas-heated home, if you qualify.

Is it cheaper to replace the furnace and AC together?

Usually, if both are near the end. Together on existing ducts runs $6,500 to $12,500, about $10,500, against roughly $6,000 each when done in separate years. One crew, one visit, one matched system.

Price the AC against the heat pump

The HVAC system cost comparison calculator puts furnace and AC, ducted heat pump and dual fuel side by side on your house, installed and over 15 years. If you have AC quotes that do not agree on size, coil or line set, the $99 review reads up to three of them and tells you why.

Compare AC and heat pumpReview my quotes, $99

Sources and further reading