Glossary · Heating, cooling & ventilation
SEER / SEER2
Also called: seasonal energy efficiency ratio · SEER rating
An air conditioner's or heat pump's cooling efficiency averaged over a whole cooling season; higher is better.
What it means
SEER2 replaced SEER in 2023 when the test procedure changed to better reflect real installations, and the numbers aren't directly comparable. It's a seasonal average, while EER or EER2 shows efficiency at a single hot condition. In heating-dominated climates, SEER matters less than heating ratings such as HSPF2 and COP.
Why it matters in an audit
Minimum SEER2 is set by regulation and ENERGY STAR and rebate levels sit above it, so it's a quick check on how efficient a quoted system is at cooling.
Typical numbers
Reference values with their sources. Your energy advisor’s report gives the figure for your own house.
| What | Value | Source |
|---|---|---|
| ENERGY STAR heat pumps (spec 6.2) | SEER2 ≥ 15.2 | energystar.gov ↗ |
| NRCan guide (older SEER metric) | Canadian minimum 14; market range 14–42 | natural-resources.canada.ca ↗ |