| Parameter | Value | Note |
|---|
How to Use the SEER Calculator
The two modes cover different jobs: one turns an old SEER nameplate into SEER2 (or back again), the other turns a known SEER2 into dollars and kilowatt-hours a year. Switch between them anytime using the tabs above the form.
Enter the rating you have and pick a direction. The conversion knocks 4 to 5% off a SEER number to reach its SEER2 equivalent for the same physical equipment, so a 14.3 SEER unit lands close to 13.4 SEER2, which happens to be Canada's current minimum for new residential central air conditioning.
Enter the cooling load in BTU/hr, the SEER2 rating (13.4 is the Canadian minimum), how many full-load hours the system runs each cooling season, and your electricity rate. A humid city like Windsor racks up far more full-load hours than a dry one like Calgary at the same square footage. For the payback on moving to a higher-efficiency unit, use the payback period calculator; for how the unit performs on the hottest days specifically, see the EER calculator.
Understanding SEER and SEER2 for Canadian cooling systems
SEER (Seasonal Energy Efficiency Ratio) measures the total cooling output of an air conditioner or heat pump over a typical cooling season divided by the total electrical energy input over that same period, expressed in BTU per watt-hour. A higher SEER means more cooling delivered per dollar of electricity spent. SEER2 replaced the original SEER testing standard with more demanding test conditions that better reflect real-world ductwork static pressure, making SEER2 a more accurate predictor of field performance.
Because SEER2 testing uses higher external static pressure, 0.5 in. w.c. versus the old test's 0.1 in. w.c., equivalent equipment typically scores 4 to 5% lower under SEER2 than it did under the old SEER standard. NRCan's own regulation guide confirms Canada's current minimum for new residential split-system central air conditioning at 13.4 SEER2, equivalent to roughly 14 SEER under the old standard. A unit achieving less than its rated SEER2 in practice is often undercharged or facing more duct resistance than it was designed for; the available static pressure calculator is a useful first check. A nameplate from before 2023 is almost always on the old SEER scale, so run it through the conversion mode above before comparing it against a current SEER2 minimum or a newer unit's spec sheet.
Calculating annual cooling cost from SEER2
Annual cooling energy (kWh) = Cooling load (BTU/hr) × Full-load hours ÷ SEER2 ÷ 1000. Full-load hours represent the equivalent number of hours the system would need to run at 100% capacity to deliver the season's total cooling, not the same as total hours the system runs, since most runtime is at partial load. This value varies significantly by Canadian climate: a hot, humid city like Windsor sees considerably more full-load hours than a cooler, drier city like Calgary, even with similar nameplate cooling capacity.
Multiply annual energy by your local electricity rate to get annual cooling cost. Canadian electricity rates vary a great deal by province; Quebec's hydroelectric-dominated grid offers some of the lowest rates in North America, while Ontario's rates can be 2-3 times higher. This rate difference significantly affects the economics of choosing a higher-SEER2 unit, since the payback period depends directly on how much each kWh saved is actually worth in your location. Use the payback period calculator to evaluate whether upgrading to a higher-efficiency unit makes financial sense given your specific electricity rate and load.
SEER2 vs. EER: seasonal average vs. peak condition
AHRI Standard 210/240 defines both metrics precisely: SEER2 represents a seasonal average across a range of outdoor temperatures, while EER (Energy Efficiency Ratio) measures efficiency at a single specified peak design condition, typically 95°F (35°C) outdoor. A unit can have a high SEER2 but a relatively lower EER if its efficiency drops off significantly at peak load. For hot Canadian climates where the air conditioner runs hard during extended summer heat waves, checking EER in addition to SEER2 gives a more complete picture of expected performance when it matters most. See the EER calculator for peak-condition analysis, and if the unit is underperforming either rating, the refrigerant charge calculator rules out an undercharge as the cause before assuming the equipment itself is the problem.
Frequently Asked Questions
SEER2 replaced SEER as the official testing standard, using higher external static pressure (0.5 in. w.c. vs. 0.1 in. w.c.) to better reflect real ductwork resistance. SEER2 ratings are typically 4-5% lower than equivalent SEER ratings for the same equipment. A unit rated 14.3 SEER is roughly equivalent to 13.4 SEER2. Canada's minimum for new residential central AC is 13.4 SEER2, approximately equal to the old 14 SEER minimum. Use the conversion mode above to translate between the two standards.
Annual energy (kWh) = Cooling load (BTU/hr) × Full-load hours ÷ SEER2 ÷ 1000. For 36,000 BTU/hr at 13.4 SEER2 with 800 full-load hours: 36,000×800/13.4/1000 = 2,149 kWh. Multiply by your electricity rate for annual cost. Higher SEER2 reduces energy proportionally; 16 SEER2 uses roughly 16% less than the 13.4 baseline for the same load. Use the energy mode above with your local rate and climate-specific full-load hours for an exact figure.
SEER2 is a seasonal average calculated across a full range of outdoor temperatures over a typical cooling season. EER measures efficiency at one specific peak design condition, typically 35°C outdoor. A unit can post a high SEER2 while performing comparatively worse at true peak load if its efficiency drops off sharply as temperature rises. For Canadian cities that see extended summer heat waves, like Windsor, Toronto, or southern Manitoba, checking EER alongside SEER2 gives a more complete picture of expected cost during the hottest days, not just the seasonal average.
Full-load hours represent the equivalent number of hours a system would need to run at 100% capacity to deliver an entire season's cooling, not the actual number of hours the system runs, since most real operating time is at partial load. This figure is highly climate-dependent within Canada: a hot, humid city sees substantially more full-load hours than a cooler, drier one, even for homes of similar size and cooling capacity. Using a generic national average instead of a climate-specific full-load hours figure can meaningfully skew the cost estimate in either direction.