How much does a higher SEER rating actually save?

Exactly one minus the old rating divided by the new one, and the useful part of that sentence is the word exactly. Going from SEER 14 to SEER 21 cuts the cooling electricity by a third. Going from 14 to 42, the two ends of NRCan's published Canadian market, cuts it by two thirds. The percentage does not depend on the size of the house, the length of the summer or the price of electricity, because all three appear on both sides of the division and cancel.

Why is the cooling answer a percentage instead of dollars?

Because turning it into dollars needs the number of full load cooling hours an Ontario summer contains, and no source found while this was built publishes one. Rather than invent a figure, the calculator gives the ratio, which is exact, and lets you apply it to your own summer bill if you know it. There is a box for that, and it is optional on purpose.

What do SEER and HSPF actually measure?

The same thing in two seasons. NRCan defines HSPF as the energy the heat pump delivers to the building over the full heating season in BTU, divided by the total energy in watt-hours it uses over the same period. SEER is the same ratio for cooling. Both are seasonal, both mix real temperature variation into one number, and both are ratios of BTU to watt-hours, which is why dividing an HSPF by 3.412142 turns it into a dimensionless coefficient of performance.

Is HSPF 13.2 realistic in Toronto?

Treat it as an upper bound. NRCan is explicit that HSPF figures are calculated for AHRI Climate Zone V, which it describes as a climate similar to Ottawa's, and that actual seasonal efficiencies vary depending on region. It also notes that a new performance standard better representing Canadian regions is under development. The rating is still the right thing to compare two machines on; it is the wrong thing to treat as a promise about your own winter.

What is a good SEER or HSPF for Ontario?

NRCan publishes the boundaries rather than a recommendation: the Canadian minimum is SEER 14 and HSPF 7.1, and market available products run to SEER 42 and HSPF 13.2. It also notes that cold climate systems, which combine variable capacity compressors with better heat exchangers and controls, are the ones reaching the top of both ranges. The calculator above is the way to decide whether the step from one number to another is worth what it costs.

Does a higher rating change how the system behaves in the cold?

Somewhat, and not in the way the number implies. A seasonal rating is an average over a whole season, so two machines with the same HSPF can behave differently on the coldest nights. What tends to travel with a high rating is a variable capacity compressor, which is the thing that actually holds output at low temperatures. The rating is a reasonable proxy for that, and the specification that settles it is the minimum operating temperature, which is a different number on a different line of the same sheet.

Is the Higher Rating Worth Paying For?

Last updated: August 25, 2026By HeatPumpIndex Evidence Desk

A yellow label with a bigger number on it is worth a specific amount of money, and this works out how much. Put the two ratings side by side and the heating difference comes back in dollars a year, the cooling difference as the exact percentage it always is.

What the rating on the label is actually worth

Heating rating, HSPF

What you have

What you are considering

NRCan puts Canada’s minimum at 7.1 and the market ceiling at 13.2, for a climate like Ottawa’s.

Cooling rating, SEER

What you have

What you are considering

Minimum 14 in Canada, market range 14 to 42.

Heat the house needs a year

kWh of heat

Shown at 27,360, the heat NRCan’s average new detached Canadian home gets from its 2,700 m³ of gas.

Your summer cooling bill, if you know it

$a season

Optional, and it stays optional: nobody publishes how many full load cooling hours an Ontario summer holds, so the cooling answer is given as a percentage unless you supply your own figure to apply it to.

Electricity price

Heating, a year

$1,031

less a year, which is 46 percent of the heating bill. HSPF 7.1 to 13.2 is a COP of 2.08 to 3.87.

At HSPF 7.113,150 kWh, $2,231
At HSPF 13.27,070 kWh, $1,200

Cooling

67%

less electricity for the same cooling. Every $100 you spend cooling today becomes $33.

The cooling figure is a ratio rather than a bill because the number of full load cooling hours in an Ontario summer is not something anybody publishes. It does not need to be: electricity used is inversely proportional to SEER, so the hours cancel and the percentage holds however long the season runs. NRCan calculates HSPF for AHRI Region V, a climate like Ottawa’s, so treat the heating figure as an upper bound on what a Toronto season would show.

Why the percentage never moves

Both ratings are defined as output divided by electricity consumed over a season. Fix the output, which is what a house needs rather than what a machine feels like delivering, and the electricity is inversely proportional to the rating. So moving from one rating to another changes consumption by one minus the ratio of the two, and that is true whatever the house costs to heat, however long the season runs and whichever tariff the household is on.

It is worth sitting with, because it is the one thing on a heat pump label that behaves predictably. HSPF 7.1 to 13.2 is a 46 percent cut in heating electricity, always. SEER 14 to 42 is a 67 percent cut in cooling electricity, always. What varies is how many dollars 46 percent turns out to be, which is why the heating side of this page has a consumption box and the cooling side has a percentage.

The corollary is less flattering to the top of the market. Because the relationship is a ratio, the gains get smaller as the numbers get bigger. Going from HSPF 7.1 to 9 saves 21 percent of the heating electricity; going from 11 to 13.2, a step of similar size, saves 17 percent of a bill that is already much smaller. The first points of efficiency are always the cheapest ones to buy.

What a seasonal rating cannot tell you

It cannot tell you about the coldest night. A seasonal figure averages a whole heating season, and NRCan is explicit that its HSPF numbers are calculated for AHRI Climate Zone V, a climate similar to Ottawa’s, with actual efficiencies varying by region. Two machines with identical HSPF can behave quite differently at minus 20, and the specification that settles that is the minimum operating temperature rather than the seasonal rating.

It also cannot tell you about capacity. A rating is an efficiency, not an output: a highly efficient machine that is too small for the house still leaves the backup heat running, and those hours run at a coefficient of performance of one whatever the label says. Rating and sizing are two separate questions and this page only answers the first.

What it can do is settle whether a price difference between two quoted models is worth paying. That is a narrow question with an exact answer, which is more than most of this subject offers, and it is the question this page was built for.

Frequently asked questions

How much does a higher SEER rating actually save?: Exactly one minus the old rating divided by the new one, and the useful part of that sentence is the word exactly. Going from SEER 14 to SEER 21 cuts the cooling electricity by a third. Going from 14 to 42, the two ends of NRCan's published Canadian market, cuts it by two thirds. The percentage does not depend on the size of the house, the length of the summer or the price of electricity, because all three appear on both sides of the division and cancel.
Why is the cooling answer a percentage instead of dollars?: Because turning it into dollars needs the number of full load cooling hours an Ontario summer contains, and no source found while this was built publishes one. Rather than invent a figure, the calculator gives the ratio, which is exact, and lets you apply it to your own summer bill if you know it. There is a box for that, and it is optional on purpose.
What do SEER and HSPF actually measure?: The same thing in two seasons. NRCan defines HSPF as the energy the heat pump delivers to the building over the full heating season in BTU, divided by the total energy in watt-hours it uses over the same period. SEER is the same ratio for cooling. Both are seasonal, both mix real temperature variation into one number, and both are ratios of BTU to watt-hours, which is why dividing an HSPF by 3.412142 turns it into a dimensionless coefficient of performance.
Is HSPF 13.2 realistic in Toronto?: Treat it as an upper bound. NRCan is explicit that HSPF figures are calculated for AHRI Climate Zone V, which it describes as a climate similar to Ottawa's, and that actual seasonal efficiencies vary depending on region. It also notes that a new performance standard better representing Canadian regions is under development. The rating is still the right thing to compare two machines on; it is the wrong thing to treat as a promise about your own winter.
What is a good SEER or HSPF for Ontario?: NRCan publishes the boundaries rather than a recommendation: the Canadian minimum is SEER 14 and HSPF 7.1, and market available products run to SEER 42 and HSPF 13.2. It also notes that cold climate systems, which combine variable capacity compressors with better heat exchangers and controls, are the ones reaching the top of both ranges. The calculator above is the way to decide whether the step from one number to another is worth what it costs.
Does a higher rating change how the system behaves in the cold?: Somewhat, and not in the way the number implies. A seasonal rating is an average over a whole season, so two machines with the same HSPF can behave differently on the coldest nights. What tends to travel with a high rating is a variable capacity compressor, which is the thing that actually holds output at low temperatures. The rating is a reasonable proxy for that, and the specification that settles it is the minimum operating temperature, which is a different number on a different line of the same sheet.

Sources

The rating definitions, the Canadian minimums and the market ranges are all from one Natural Resources Canada publication. The electricity prices are the Ontario Energy Board’s with Toronto Hydro’s two volumetric charges added, and the default heat demand is NRCan’s figure for an average new detached Canadian home.

The two questions this one does not answer

Whether the machine is the right size, and whether it is still running when it is coldest. Both have their own page on HeatPumpIndex, and both matter more than a rating on a house that gets either one wrong.

What size the house needs Whether it runs at your design temperature