“They stop working below freezing.”
Freezing is 0°C. The cold-climate listing test is at −15°C, and it requires the unit to still deliver at least 70 percent of its rated capacity and a COP of at least 1.8. NRCan NRCan’s own guide describes air-source units running well below freezing, with a minimum operating temperature often somewhere between −15°C and −25°C. NRCan guide Below freezing is the normal operating range, not the failure point.
“A cold-climate model carries the house at −40.”
Whitehorse and Yellowknife are both −41°C at the January 2.5% design temperature. NRC tables Yukon’s dual-fuel rule asks for a balance point of −20°C, not −41°C, and it asks for oil, propane, or wood beside the heat pump. Terms The Yellowknife monitoring note says a secondary source was still required in extreme cold. AEA A unit can be excellent and still not be the only heat in the house.
“Yukon banned electric heat pumps.”
The September 3, 2026 terms still pay for heat pumps: dual fuel up to $15,000, Good Energy up to $10,500 on an existing home, and the Affordable Heat Pump Program up to $24,000. What the new program pushes is a non-electric backup on electrically heated houses, because the grid problem is peak demand in a cold snap. All-electric is a different path, with Peak Smart enrollment in the Good Energy rules. It is not a ban.
“The rated tonnage is the tonnage at −30.”
Rated heating capacity is at 8.3°C. Capacity maintenance tells you the fraction still there at −15°C. Nothing on the listing sticker is a measurement at −30°C or −40°C. If the manufacturer does not publish a capacity at that temperature, nobody on a forum knows it either.
Related pages
- 11 Best heat pumps for the North, 2026
A criteria-first comparison. Not a ranked shopping list.
- 12 Log home reality check
What changes when the envelope is logs: load, air leakage, and where a heat pump struggles.
- 13 Retrofit vs new build
Why the same machine is a different project in an existing house than in a new one.
- 14 Oil-to-heat-pump conversion
For houses that still heat with oil after the federal grant window closed.
Sources
Every figure on this page comes from the documents below. If a later official update conflicts, the official update wins.
- NRCan heat pump guide
Balance point, supplementary heat, and operation below freezing as a normal part of the design.
- NRCan listing criteria
Cold-climate units are tested at −15°C, not certified to carry a house at −40°C.
- Yukon terms
−20°C balance point and a required non-electric backup for dual fuel. Good Energy and AHPP still exist for heat pumps.
- AEA Yellowknife note
Secondary heat still required in extreme cold.
- NRC climatic tables
Whitehorse and Yellowknife January 2.5% design temperature −41°C.