Our heat pump does fine down to about -5 F, and doesn’t use any resistive heating elements.
It will produce heat down to -15F, but at those temperatures the house loses heat faster than the heat pump can replenish. If the house had better insulation, it would probably keep up.
But we knew and understood it’s limitations going in, so when it’s very cold we augment with wood heat.
Fortunately -15 is rare where the house is situated, and below 0 only happens a few times, most years.
It costs far less to run than our propane furnace did, and keeps the house more comfortable to boot.

Quote from: Coen on February 23, 2023, 04:38 PM

Quote from: JimH2 on February 22, 2023, 10:26 PM

If you are insistent on a heat pump consider getting one and using the furnace as the backup heat source.

The whole point about getting a heat pump is you can dumb your natural gas connection, saving in fixed cost.

Snip.

In B.C., Vancouver, for example, some people have heat pumps, and they serve houses fine year round. But not in Alberta where temperatures can drop to -30C or lower. These past couple of days we have had -25 C (-40C windchill). No responsible heating companies here will advise a customer to install a heat pump alone without a furnace as a backup. Pipe bursts aren't uncommon in our winter. Our water tanks are commonly gas-heated. So heat pumps work for some, but not necessarily for all.

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In that case you go with the ground source heatpump. The payoff is faster then anyway because of the higher use. You can connect the tank hot tap water to it too. A little bit lower efficiency for the hot tap water due to the higher temperature gap is to be expected, but as it's usually a tiny fraction of total heating that is negligible. If you like to shower a lot or have a bigger household, get a heat exchanger for the shower waste water.

What "heating companies" advise is usually just food for the trash bin. I've talked about the installation branche in NL before; to prevent CO deaths the government now outlawed (well, five times and three years delayed) installing and maintaining gas-burning heating devices unless certified. However, the total amount of CO deaths is "5 to 10" per year and in 95% of cases it's because of recent installation or maintenance done by a certified installer. Soooo... if we assume the 5% of CO deaths is currently caused by faulty DIY installation, the maximum lives saved per year is .25 to 0.50
I'd say even less or negative, because there is no legal requirement to actually have maintenance done.

But the whole circus of bureacrats, schools and educators definitely benefited...

Ottawa hit -32C (before windchill) earlier this month and we were fine with our heat pump.
We installed a Mitsubishi Zuba  a year and a half ago. This is our second winter with it and it has been great. We got rid of the furnace and have electric heaters as backup. In all this time I think the electric heater came on 1 night. And that was just for maybe 30 minutes.

In the UK, we only have H (setting fire to our furniture because the cost of natural gas and electricity are stratospheric) and V (opening a window). It only gets hot enough for us to need AC once every 10-15 years, so on that day, we take off our shirts instead and complain about how hot it is. And we aren't white - we're blue. It takes us a whole week of sunbathing to turn white.

Was the UK even slower with minimum insulation requirements as NL was?

Insulation? You mean the 2 vests, 4 shirts, 3 sweaters and 2 coats we all wear 24/7?