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Heat pump or electric furnace alone: what the COP changes
An electric furnace turns electricity into heat, one for one. A heat pump collects heat outdoors and brings it into the house: for every kWh of electricity, it delivers more. That ratio is called the COP. This guide shows it with two certified central heat pumps, at the temperatures where NEEP measured them.
CENTAURI XLTH R32 · 36,000 BTU
AMUH36KUAS / AOUH36KUAH1 · AHRI 217895717
See the product page
EVOX G3 · 36,000 BTU
MAUSE-H36B-2A / MO1SE-H36B-2A · AHRI 215471343
See the product pageWhat the electricity costs, in dollars, winter and summer
AirGreen estimate for the same 36,000 BTU/h (3-ton) house in Montréal, on Hydro-Québec Rate D, taxes included, with the same method as on all our comparison pages. The reference is electric baseboards: 1 kWh of heat for 1 kWh of electricity. An electric furnace alone does the same, since NRCan gives it 100% efficiency: the reference therefore holds for it too, minus the cooling, which it does not provide.
How this amount is calculated
- Heat to supply over the winter. A house whose heat loss reaches 36,000 BTU/h ( kW) at −23.1 °C, the Montréal design temperature: kW × 24 h × 4,167 degree-days ÷ (18 − (−23.1)) = kWh of heat for round-the-clock heating, all winter. Heating degree-days (18 °C base) and design temperature: Natural Resources Canada, HOT2000 climate data, Montréal Intl station. With fewer hours a day (“Heating” slider), the heat is reduced in the same proportion, for the heat pump as for the baseboards: this simplification ignores the recovery after a temperature setback.
- Heating electricity. Heat pump: heat × 3.412 ÷ HSPF2 Region V, the AHRI certificate value published by NEEP. Region V is the coldest in the standard, and its calculation includes the electric backup heat expected when the heat pump is no longer enough. Electric baseboards, and an electric furnace alone: 1 kWh of electricity for 1 kWh of heat.
- Cooling electricity. 36,000 BTU/h ÷ SEER2 × hours a day × 60 days ÷ 1,000: the method of Hydro-Québec’s air-conditioning calculator, with the seasonal SEER2 efficiency from the AHRI certificate. The number of hours is a scenario, adjustable above from 1 to 24 h. At 24 h, the calculation assumes rated capacity all day long: that is a ceiling, since a variable-speed unit slows down once the room reaches its set temperature.
- Price. Hydro-Québec Rate D in effect April 1, 2026: 7.065¢ per kWh up to 40 kWh a day, 11.142¢ beyond; the average price, 9.104¢, is the one Hydro-Québec’s calculators use. GST and QST included. Grid access charges, the same with or without a heat pump, are not counted.
AirGreen method v1.1, November 9, 2026. An estimate is a way to compare units under the same conditions. The actual bill depends on the house, its insulation, the settings and how it is used; this amount is not a promise.
One kWh of electricity goes in. How much heat comes out?
Pick a heat pump, a certified temperature and a power level. On the left, the electricity and the heat captured outside come together in the house; the thickness of the bands follows the COPs certified by NEEP. On the right, the electric furnace: what goes in comes out, no more, no less.
Bands to scale with each combination’s NEEP-certified COPs (consulted November 9, 2026). A band is only drawn at published temperatures: between two points, nothing is made up. The electric furnace is 100% efficient: all the electrical energy becomes heat (NRCan, “Heating with Electricity”, EnerGuide, revised March 2003). A heat pump’s COP is the heat delivered divided by the electricity consumed; NRCan gives the example of a heat pump that uses 1 kW to transfer 3 kW of heat, a COP of 3.
Your situation, in four questions
These questions calculate nothing: they show what each option changes in your home. Neither is ranked, and only a visit can look at your ducts and your electrical panel.
What changes for the house
Heating through the ducts stays the same. What changes is how the heat is obtained, and what the house gains in summer.
| For the homeowner | Heat pump (examples) | Electric furnace alone |
|---|---|---|
| Where the heat comes from | It is captured in the outdoor air and brought into the house | It is produced by heating elements |
| Heat per kWh of electricity | The certified COP: from 1.82 to 3.89 kWh for the CENTAURI XLTH, from 1.28 to 4.45 kWh for the EVOX G3, depending on temperature and power | 1 kWh: 100% efficiency |
| In extreme cold | COP and capacity drop when it is very cold; backup heat takes over when needed | The same efficiency, whatever the temperature outside |
| Summer | Cooling by the same heat pump | No cooling |
| What is installed | An outdoor unit, the piping, and a coil in the duct | The furnace alone, in the basement |
| The filter | At the indoor unit’s return | At the furnace’s return |
COP: NEEP-certified values of both examples, from the coldest published point up to 8.3 °C. Electric furnace: NRCan, “Heating with Electricity”. An existing electric furnace can also stay in place and become a heat pump’s backup: see our guide “Replace the furnace, or add a heat pump to it?”.
Below −15 °C: capacity and COP, point by point
NEEP measures both examples at −15 °C, then at their coldest point: −26.1 °C for the CENTAURI XLTH, −30 °C for the EVOX G3. The table gives the COP at each published point. For the electric furnace, the COP stays at 1 at all these temperatures.
Before you choose
What effect on my bill?
The “Season cost” section gives an AirGreen estimate, calculated the same way on all our pages; baseboards serve as the reference, and an electric furnace alone has the same 100% efficiency. The actual bill depends on the house, its insulation, the settings and the rates: this amount is for comparison, not a promise.
What happens colder than the last published point?
The CENTAURI XLTH certified record stops at −26.1 °C, the EVOX G3 record at −30 °C. FUJITSU AIRSTAGE states heating with no low-temperature cutoff, without giving a capacity below −26 °C; MIDEA states a heating range down to −30 °C. Below that, whatever heat is missing comes from the electric backup, at a COP of 1.
Why three COPs at the same temperature?
Because a heat pump modulates its output. NEEP publishes the COP at minimum, rated and maximum power. At −15 °C, the CENTAURI XLTH shows a COP of 3.86 at 7,900 BTU/h and 1.98 at 41,000 BTU/h: the harder it works, the lower its COP.
Should I keep the electric furnace?
You can: with an ADD-ON system, it stays in place and its elements become the backup. Our guide “Replace the furnace, or add a heat pump to it?” covers both paths.
Why two examples from different brands?
To show that the COP belongs to each certified combination: two heat pumps of the same size do not have the same values, point by point. The page ranks neither one.
The AHRI and NEEP values of both examples
| Certified value | CENTAURI XLTH | EVOX G3 |
|---|---|---|
| Cooling | ||
| Rated capacity at 35 °C | 36,000 BTU/h | 36,000 BTU/h |
| SEER2 | 18.3 | 18.0 |
| EER2 | 11.4 | 12.0 |
| Heating, same conditions | ||
| HSPF2 Region IV / V | 10.2 / 8.2 | 10.0 / 8.2 |
| 8.3 °C: min. / rated / max.BTU/h | 9,200 / 38,000 / 43,000 | 11,400 / 37,000 / 47,000 |
| 8.3 °C: COP at min., rated, max. | 3.80 / 3.89 / 3.28 | 4.45 / 3.50 / 3.27 |
| −8.3 °C: min. / rated / max.BTU/h | 8,300 / 25,200 / 41,600 | 11,000 / 33,000 / 41,500 |
| −8.3 °C: COP at min., rated, max. | 3.86 / 2.90 / 2.25 | 2.58 / 2.50 / 2.21 |
| −15 °C: min. / rated / max.BTU/h | 7,900 / 41,000 / 41,000 | 8,900 / 37,400 / 37,400 |
| −15 °C: COP at min., rated, max. | 3.86 / 1.98 / 1.98 | 2.16 / 1.90 / 1.90 |
| Coldest published point | ||
| Temperature | −26.1 °C (−15 °F) | −30 °C (−22 °F) |
| Capacity min. / max.BTU/h | 6,000 / 32,000 | 4,700 / 27,600 |
| COP at min. and max. | 2.93 / 1.82 | 1.28 / 1.56 |
| Listings and refrigerant | ||
| ENERGY STAR / cold climate (NEEP) | Yes / Yes | Yes / Yes |
| AHRI certificate · NEEP record | 217895717 · 306746 | 215471343 · 387396 |
| RefrigerantGWP per the IPCC (AR4); ASHRAE 34 class | R-32 · GWP 675 · A2L | R-454B · GWP 466 · A2L |
higher marks the higher value of a given measure, under the same conditions. It is not a recommendation. Capacities and COPs at each test point are not highlighted: which one is higher changes from point to point. The coldest points are at different temperatures and do not compare with each other.
The COP is the theory. Your house is the project.
Our estimator comes over free of charge to look at your furnace, your ducts and the spot for an outdoor unit. Written quote within 24 hours.
Where each figure comes from
Data checked on November 9, 2026. This guide explains what the COP changes; it designates no unit and no brand. The models cited serve as examples, sold by AirGreen. Performance: AHRI certificates and the NEEP database. Operating ranges: per the manufacturer. Electric furnace: NRCan. When a source contradicts the AHRI certificate, the certificate prevails.
Trademarks. FUJITSU AIRSTAGE, CENTAURI, MIDEA and EVOX are trademarks of their respective owners. Logos are used only to identify the products shown. AirGreen is a dealer for these brands; this page is not produced, sponsored or endorsed by the manufacturers.
Photos: AirGreen and the manufacturers, for identification.
Does a figure look wrong to you? Write to us: every reported figure is checked again.