Central air conditioning is close to standard in Hamilton-area houses now, and most of the quotes homeowners request are replacements: a 15-year-old outdoor unit that has finally quit, or one on R-22 refrigerant that is too expensive to recharge. This guide gives typical 2026 installed prices, before HST, for the Hamilton, Burlington and Haldimand area, explains what moves them, and covers the question that now comes with almost every AC quote: should it be a heat pump?
Typical installed prices
- Standard central AC, replacing an old one (single-stage, new indoor coil): $4,000 to $7,500
- High-efficiency two-stage or variable-speed AC: $6,500 to $10,000
- Adding central air to a house with ducts but no AC: $5,500 to $9,500
- Furnace and AC replaced together: $8,000 to $14,000
- Ductless mini-split, single room: $4,000 to $7,000
- Heat pump in place of an AC, keeping the furnace: $8,000 to $14,000, before rebates
The standard price includes recovering refrigerant from the old system, removing it, a new pad, the outdoor unit and matching indoor coil, the refrigerant line set connection, electrical hook-up through an outdoor disconnect, a condensate drain and start-up. The HVAC cost calculator adjusts these for house size and equipment level.
What moves the price
Size in tons
Air conditioners are sold in tons of cooling. A typical detached house in the area needs 1.5 to 4 tons, and each half-ton step adds a few hundred dollars. The bigger cost of getting it wrong is comfort: oversized units cool quickly but leave humidity behind. The furnace and AC size calculator gives a starting point.
Efficiency and compressor type
Efficiency is rated in SEER2. A single-stage unit runs flat out or not at all. Two-stage and inverter-driven variable-speed units run longer at lower output, using less electricity and pulling more moisture out of humid summer air. They cost more up front, and the payback in electricity alone is slow in Ontario’s fairly short cooling season, so the case is mostly comfort and noise.
The indoor coil and furnace
The outdoor unit is half the system. The indoor coil sits on the furnace and must be matched to the outdoor unit, and the furnace blower must move enough air for it. An old furnace with a weak blower can limit a new AC. That is why contractors often suggest replacing both at once when the furnace is near the end of its life.
Line set, pad and electrical
Reusing an existing copper line set saves money if it is the right size, in good condition and compatible with the new refrigerant; otherwise it is replaced. A first-time install needs a new line set, a pad, a disconnect and a new circuit, which is why it costs more. Long runs from the furnace to the outdoor unit add labour.
Refrigerant changes
New air conditioners are moving to lower-impact refrigerants such as R-454B and R-32 under Canada’s rules on high-warming refrigerants. Prices of new equipment rose in the transition. The main thing for homeowners is that a new outdoor unit needs a matching coil, so a cheap swap of the outdoor unit alone is rarely the right answer.
The heat pump question
A heat pump is an air conditioner that also heats. Installed the same way, on the same coil and line set, it cools identically. In winter it heats the house through most of the season, with your gas furnace taking over on the coldest days. The extra cost over an AC is often $2,000 to $5,000, and heat pumps qualify for Home Renovation Savings rebates that air conditioners do not. Whether it saves money on heating depends on your fuel and prices; the heat pump vs gas calculator runs your numbers, and heat pump vs furnace explains the trade-offs.
Running costs
A central air conditioner in a typical Hamilton house might use roughly 1,000 to 2,500 kWh in a summer, depending on size, efficiency, how cool you keep the house and how hot the summer is. At Ontario electricity prices that is usually a few hundred dollars a season. Closing blinds on sunny windows, sealing ducts in hot attics and a programmable schedule make more difference than most upgrades.
Noise, placement and the neighbours
On the tight lots of the lower city, east Mountain and older Burlington, where the outdoor unit goes can matter as much as which unit you buy. Ask for the sound rating in decibels, and compare: variable-speed units are usually noticeably quieter at low speed. Keep the unit at least the manufacturer’s clearance from walls, fences and shrubs so it can breathe, and away from bedroom windows, yours and the neighbour’s. Moving an existing unit to a better spot adds line set and electrical work, but it is cheapest to do during a replacement.
Comparing AC quotes
- Make sure each quote names the outdoor unit and the indoor coil model numbers.
- Ask how they sized it and whether they did a heat-gain calculation.
- Check whether the line set is reused or replaced, and whether the electrical work and permit are included.
- Ask for a heat pump price on the same quote.
- Compare labour warranties, not only the manufacturer’s parts warranty.
When to buy
The best time to replace an AC is before it fails: in April, May or September, when contractors have time to quote and install. Once a July heat wave hits, everybody calls at once.
Getting a quote
Send one request and we pass it to one licensed contractor who works your area. They visit, size the house and quote an AC, a heat pump or both. See central air installation for what the job involves, or AC repair if yours might still be fixable.
Questions people ask
How much does central air cost to install in Ontario?
A standard replacement usually costs $4,000 to $7,500 installed. Adding central air to a house that never had it costs $5,500 to $9,500 because of the new line set, pad and electrical work.
How long does a central air conditioner last?
Usually 12 to 18 years in southern Ontario. Skipped maintenance, a dirty outdoor coil and oversizing all shorten it.
Is a heat pump more expensive than an air conditioner?
Usually by $2,000 to $5,000 for a comparable unit, before rebates. It also heats the house, which can cut gas use and qualify for a Home Renovation Savings rebate.
Can I replace just the outdoor unit?
Rarely a good idea. The indoor coil needs to match the outdoor unit and its refrigerant to work properly and to keep the warranty.