Heat pumps can't take the cold? Nordics debunk the myth

It never ceases to amaze me how people don't read past the title 🤦 There are people debating about -10 to -30C when the article clearly states that it works in those temperatures. Not only does it work, it's twice as efficient as electrical heating at those temperatures.

Good Lord - $2600 for a whole house system? I think that's what my local (mid-Atlantic US) HVAC shop is getting for a single-room mini-split.

Wait until people find out about ground-source heat pumps and water heater heat pumps. What you get out of those is more consistent year round, too. It's almost like leveraging technology has benefits over just burning carbon and hydrogen to make heat.

Hell yeah, we've got a heat pump and we're in Canada where it can get to -40°C (which is coincidentally also -40°F) and that thing works like a beast. Fortunately we also have the cheapest electricity in North America so the decision was easy.

It depends on the model (and the price), I'm in Québec where we have -30°C (-22F) about every winter, my heatpump is mid-range, and works fine until -20C (-4F) so 95% of the time. It is set to 23C (73F) and it's between 21-23 everywhere in the house. The electric baseboard are set to 21C (70F) as backup.

So yeah, heat pumps can works great in winter, no problem.

Also as written in the article, with defrosting and variable speed compressors, it is very efficient. Mine is Energy Star compliant, and act as air conditionner in summer.

How is this a myth? Nobody with more than two braincells thinks that heat pump heaters don't work in the cold.

If we start comparing everything that idiots think to a mythological mystery worthy of note, we'll be here for an eternity.

my heart goes out to the three little birds

Same with EVs. Don't work in cold weather. Except in the Nordics.

It's not so much a myth as it is old information that is no longer accurate

The heat pumps that were available 20-30 years ago weren't effective/efficienct enough at low outdoor temperatures to be practical.

Was it necessary to kill birds th?

Not sure I would call this a "myth". It's just that technology has progressed to the point that it's less of an issue.

Mine stopped working at 100% when it got <20*F and turned into a giant popsicle.

I mean, it's not about them not working, it's the efficiency. Most models will switch to a normal electric heater, if they can't extract anymore heat from the surroundings. At which temperature that happens, depends on your type of heat pump.

Permanently Deleted

I want to understand what happens when it's too cold out. And just running in pure air sourced HP mode, without supplemental heat.

Does it keep running at 100% but produces no heat? Limited heat? Does the house get colder and colder until everyone turns into a popsicle?

Or does it only heat the house to 18c instead of 20c?

In a climate where the low is -10c, how well does it work?

No that's just my shitty heat pump. Sigh...

So my question with heat pumps is more how much does humidity effect the efficiency? Where I live is high elevation, has cold winters, but the air is dry as fuck. Single digit humidity for a month wouldn't be unusual.

My understanding is that heat pumps work best with humidity since moving moisture is part of how the heat is produced. When does a reasonably priced heat pump start falling off in efficiency?

There is a really, really big caveat here.

While all of this is true, and while heat pumps are definitely more efficient than gas/oil/electric heat, you MUST have a well-insulated home without drafts. If your home is not well insulated, or is drafty, then heat pumps likely will not keep your home at a comfortable temperature.

A standard furnace works by kicking on when heat drops below the set point of your thermostat, and then it blasts heated air until the whole space is a certain temperature above the set point on your thermostat, and then shuts off. The most efficient heat pumps are constantly trickling a little heat at a time, rather than cycling on and off. If your home is poorly insulated or drafty, then you can end up losing heat faster than the heat pump can bring it in. The better your insulation and the better sealed your home is, the better your results with a heat pump will be.

Unfortunately, my home is largely uninsulated and pretty drafty; without doing a pretty significant amount of work, at a fairly steep cost, I can't retrofit to a heat pump.

I bought into the heat pump hype until I bought a house with a furnace. Up until then I lived in apartments with heat pumps. I was stunned about how much better it was than any place I've lived before. It was used for it taking forever to get warm and always feeling colder than the thermostat would indicate. With a furnace it got warm quick, and it truly felt warm once it reached temperature. My power+heat bill was significantly lower per sqft than my power bill in my apartment.

I've lived in the Midwest, the Mountain West, and the South. I experienced the shortcomings of heat pumps in every place.

This article, which I believe to be geared at convincing US readers that heat pumps are great, also does some things that are extremely disingenuous.

For one, most heat pumps in Norway are geothermal heat pumps. Those are extremely different units that are well known to both be more energy efficient and function at much lower temperatures than air source heat pumps that are typically pushed in the US. The example where they interview a guy with an air source heat pump seems like an almost intentional misdirection.

Second, the author uses a comparison to electric furnaces. That has been widely known for years to be hilariously inefficient. As such it's fairly rare to see in the US. The most common sources of heat in the US are air source heat pumps (in places like AZ and Texas), oil radiators, and gas furnaces. Depending on energy prices, these could be significantly cheaper depending on utility cost. I understand Norway has specific conditions that make oil and gas usage much less appealing but, again, this article is clearly targeted towards westerners.

I feel like this is EVs all over again. Heat pumps have a lot of potential. They will one day before the de facto standard almost everywhere. However they have serious shortcomings and the idea that they are ready to be a drop in replacement in the vast majority of cases is hopium.

EDIT: Since everyone is getting caught up over the word "efficient". Electric furnaces are hilariously expensive.