If you're shopping for a new air conditioner in Ontario, you've probably seen the term "SEER" on every spec sheet. It stands for Seasonal Energy Efficiency Ratio, and it's the single most important number for understanding how much your AC will cost to run — not just to buy.
Here's a practical breakdown of what SEER means, what the tiers look like in real dollars, and which range makes the most sense for most Ontario homeowners.
What SEER Actually Measures
SEER measures the total cooling output (in BTUs) divided by the total electrical energy input (in watt-hours) over an entire cooling season. Think of it like fuel economy for your car — a higher number means more cooling per dollar of electricity.
The minimum SEER allowed for new installations in Canada is 14 SEER. You can't legally install anything lower. From there, units go up to 26 SEER or higher, with price increasing at every step.
The SEER Tiers
| SEER Rating | Tier | Approx. Annual Cost* | Best For |
|---|---|---|---|
| 14–15 SEER | Standard | $480–$540 | Budget-conscious, moderate use |
| 16–18 SEER | High Efficiency | $360–$430 | Most Ontario homes — sweet spot |
| 19–21 SEER | Premium | $280–$350 | Larger homes, all-day cooling |
| 22+ SEER | Ultra | $220–$270 | Max comfort, minimal environmental footprint |
*Estimates for a typical 2,000 sq. ft. home in York Region based on Ontario electricity rates.
The Sweet Spot for Ontario Homes
For most homeowners in our service area — Newmarket, Aurora, Richmond Hill, Vaughan, and Markham — we recommend 16 to 18 SEER. Here's why:
- Ontario has a moderate cooling season. We get roughly 3–4 months of consistent AC use, compared to 6+ months in the southern U.S. The energy savings from ultra-high SEER units take longer to pay back.
- The price jump from 14 to 16 SEER is modest. Typically $400–$800 more on the installed price. The jump from 18 to 22 can be $2,000–$4,000, with diminishing returns in our climate.
- 16+ SEER units are quieter and more consistent. Most use two-stage or variable-speed compressors, which deliver noticeably better comfort even apart from the energy savings.
When to Go Higher
A 20+ SEER unit makes sense when:
- Your home is 2,500+ square feet and you run the AC heavily
- You work from home and the AC runs all day, every day
- You're planning to stay in the home for 10+ years — the payback window matters
- Noise is a concern — the highest-SEER models are the quietest on the market
- Environmental impact is a priority for you
When 14 SEER Is Fine
There's no shame in the base model. A 14 SEER unit makes sense if:
- Budget is tight and you need a working AC now
- The home is small (under 1,200 sq. ft.) or used seasonally
- You're selling the property in the near term
A new 14 SEER unit is still dramatically more efficient than a 10-year-old system running at an effective 8–10 SEER due to wear.
SEER2 — The New Standard
Starting in 2023, the industry transitioned to SEER2, which uses an updated testing procedure that produces slightly lower numbers. A 16 SEER unit under the old standard is roughly equivalent to a 15.2 SEER2 under the new one. Don't be alarmed if newer models show lower numbers — it's the same efficiency, different yardstick.
At AC Experts, we size and spec every system to the home — not to a sales target. If you're comparing quotes and want a second opinion on whether the recommended SEER tier makes sense for your space, give us a call. We're happy to walk through the math.