| Parameter | Value | Note |
|---|
How to Use the HSPF Calculator
Conversion mode translates an old HSPF nameplate into HSPF2 or back again. Energy and cost mode turns a known HSPF2 into kilowatt-hours and dollars per year. The tabs above the form switch between them at any time.
Enter the rating you have and pick the direction. The tool multiplies an HSPF by 0.865 to get an HSPF2 on the Region IV basis that most AHRI ratings use, then divides by 1.15 for a rough Region V figure. A 9.0 HSPF unit comes out near 7.8 on Region IV and near 6.8 on Region V, so it sits above the Canadian minimum of 6.0 but with less room than the nameplate suggests.
Enter heating capacity, the HSPF2 (the default of 6.0 is the Canadian minimum), full-load heating hours, and your electricity rate. Capacity should come from a heat loss calculation, not from the size of the old furnace, and the heat pump sizing calculator is a sensible place to get it. Full-load hours differ a lot by city, and the tooltip on that field gives ranges for Vancouver, Toronto, and Winnipeg.
HSPF and HSPF2: measuring heat pump heating season performance
HSPF, the Heating Seasonal Performance Factor, is the heat a heat pump delivers over a whole heating season in Btu divided by the electricity it uses in watt-hours. It plays the same role for heating that SEER plays for cooling. A higher number means less electricity per unit of heat, and dividing HSPF by 3.412 gives the seasonal average coefficient of performance, so an HSPF of 10 is a season-long COP of about 2.9.
Why HSPF2 numbers look lower
HSPF2 comes from the newer M1 test procedure, which replaced the older method for units built from 2023. The M1 test raised the external static pressure applied to ducted systems and changed how defrost is credited, so the same physical heat pump earns a lower figure. The clearest published pair is the U.S. minimum for split-system heat pumps, which went from 8.8 HSPF to 7.5 HSPF2, a drop of about 15%. This calculator uses a flat factor of 0.865, or 13.5% lower, as a round-number approximation. Real conversions vary with the equipment, especially ductless and variable-speed models.
Canada's minimum is set on Region V
Canadian and U.S. numbers are not directly comparable. The U.S. standard uses climate Region IV, while NRCan's split-system central heat pump regulation sets the requirement on Region V, a colder profile. For a single-phase split-system unit the minimum is HSPF2 (Region V) of 6.0, alongside a SEER2 of 14.3. The U.S. figure of 7.5 is the Region IV minimum and is not a Canadian requirement, so a manufacturer’s brochure quoting 7.5 may be describing the American standard. For compliance, the Region V HSPF2 on the certified energy efficiency report is the number that counts.
Calculating annual heat pump heating cost
Annual heating energy in kWh is heating capacity in Btu/h times full-load heating hours, divided by HSPF2, divided by 1,000. Multiply by your electricity rate for the yearly cost. The default example, 36,000 Btu/h over 2,000 hours at an HSPF2 of 6.0 and $0.14 per kWh, delivers 72 MMBtu of heat using 12,000 kWh, which costs $1,680 a year. Delivering the same heat with electric resistance takes about 21,100 kWh, or roughly $2,950, so the minimum-efficiency heat pump cuts the bill by about 43%. Moving to an HSPF2 of 9.0 drops the heat pump’s energy to 8,000 kWh and $1,120, saving another $560 a year at that rate. To price the same heat from gas, run the AFUE calculator and compare, or use the heat pump vs furnace calculator for the full side-by-side.
Why HSPF2 alone doesn't tell the cold-climate story
An HSPF2 is a seasonal average for a defined climate, not a promise about the coldest week. NRCan’s homeowner guide to heat pumps notes that the Region V figure best matches an Ottawa-type climate and can run lower where there are more heating degree days, which includes much of the Prairies. The guide also explains that most air-source units have a minimum operating temperature, between −15°C and −25°C on newer models, below which a supplementary heat source has to carry the load. When you compare two units, look at capacity and COP at low outdoor temperatures on the data sheet as well as the seasonal number.
Planning the backup heat
Because capacity falls as the outdoor temperature drops, an air-source heat pump meets the house load down to a balance point and needs help below it. That help is either electric resistance elements or, in a hybrid setup, a gas furnace that takes over below a set outdoor temperature. Each arrangement shifts the annual energy figure this tool produces, since resistance heat costs far more per kWh delivered than the heat pump. The dual fuel calculator works through a hybrid heat pump and furnace setup in more detail.
Frequently Asked Questions
HSPF measures total heating output over a season divided by total electrical input, in BTU/Wh. HSPF2 replaced it using a more demanding test, similar to the SEER2 transition on the cooling side, and runs roughly 12 to 15% lower than an HSPF rating for the same equipment. Canada's minimum for new split-system heat pumps is an HSPF2 of 6.0, tested on climate Region V, which is colder than the Region IV basis most HSPF2 numbers are published on. Use the conversion mode above to move between the two ratings.
An HSPF2 is a seasonal average for a defined climate region, not a measure of performance in the coldest week of the year. NRCan notes the Region V figure is most representative of an Ottawa-type climate and can run lower in places with more heating degree days, which covers much of the Prairies. A heat pump's nameplate HSPF2 alone doesn't confirm strong cold-weather performance in Winnipeg or Edmonton, so check the capacity and COP at low outdoor temperatures on the manufacturer's data sheet rather than relying on the seasonal average alone.
Annual heating energy in kWh equals heating capacity in BTU/hr multiplied by full-load heating hours, divided by HSPF2, divided by 1000. Multiply that result by your electricity rate for the annual cost. In the calculator's default example, 36,000 BTU/hr over 2,000 hours at an HSPF2 of 6.0 and $0.14 per kWh comes to 12,000 kWh and $1,680 a year; the same heat from electric resistance would cost about $2,950. Full-load heating hours differ a lot by city: a mild coastal climate like Vancouver needs far fewer equivalent hours per year than a longer, colder season like Winnipeg's.
An HSPF2 of 6.0 on Region V is the regulatory floor for new split-system air-source heat pumps in Canada, and it is a seasonal average, not a guarantee of strong performance in extreme cold. Cold-climate-rated units on the market today reach HSPF2 numbers well above that, with some approaching 13, and typically hold more of their capacity at −15°C and −25°C as well. For homes in the Prairies, northern Ontario, or Quebec with prolonged stretches below −20°C, a unit rated well above the minimum, with cold-weather capacity data confirmed, performs more reliably than one at the bare minimum.