By installing a heat pump in his house in the hills of Oslo, Oyvind Solstad killed three birds with one stone, improving his comfort, finances and climate footprint.
Heat pumps can't take the cold? Nordics debunk the myth::By installing a heat pump in his house in the hills of Oslo, Oyvind Solstad killed three birds with one stone, improving his comfort, finances and climate footprint.
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.
I think it does, and it seems to work because of a defrosting feature that earlier models didn't have. But I wouldn't say it does so very clearly. Unless I missed it.
Good Lord - $2600 for a whole house system? I think that's what my local (mid-Atlantic US) HVAC shop is getting for a single-room mini-split.
Wait until people find out about ground-source heat pumps and water heater heat pumps. What you get out of those is more consistent year round, too. It's almost like leveraging technology has benefits over just burning carbon and hydrogen to make heat.
That is absolutely bonkers. I put one in myself for my one room garage that I converted to a place to hang. Cost 720$ after tax for a Pioneer mini split. It's entering its third year in use and I love it. That being said, I wouldn't be so risky as to put my own in when its task was heating or cooling my home. Just my garage is my problem, the rest is my family, and so I paid. But I got a whole home solution, two floors, Carrier units, for about $15k.
I believe what you're looking for is out there and not ridiculous price.
Also in rural America. How did you get someone not to laugh at you when you asked? God I fucking hate the small mindedness around me, but I couldn't stand the city either. I cannot find someone to put one in my house so I'm going to have to install it myself next summer.
$2600 is utter bullshit. I had several quotes for a 1000sf house, not a single one was under 16000 installed, after rebates. My payback period was going to be almost 20 years even against a medium efficiency gas furnace.
And this is why the comments here miss the point- sure, heat pumps nowadays can work that low but in a lot of places the payoff period is well outside what anyone is looking at.
I don't think Geothermal makes much sense unless you live in one of the extremes, mainly the cold one, For example I an from Slovakia and I don't think the temperature here went under -20C in the last few years, I barely remember any days going under - 10C, so you would be paying quite a premium for a geothermal heat pump for rather marginal gains, it would certainly need quite a good analysis if the difference in performance would ever pay for the price difference, especially with better insulation and heat recuperation systems becoming mandatory.
There are also things like heat pump based driers now on the market btw.
I suspect it’s mostly a function of mass availability. Even here in the states ground source heatpumps are rare, even though the systems are more reliable (since there is no equipment exposed to weather) and a shallow borehole isn’t excessively expensive.
I’d forgotten about heat pump clothes dryers. Those are fascinating, and really interesting for older buildings or locations without close access to exterior venting.
Shallow geothermal is basically dead in most of the world because it's too much hit and miss, the geology is simply too complex and involved (and underground) to predict. There's also a fuckton of issues with water ingress, minerals that like to expand when getting wet and such. You can't really take Iceland as an example for countries not straddling a continental rift.
Deep geothermal is utterly reliable but for the longest time drilling that deep was just too expensive. Plasma deep drilling is a solution but it's still in its infancy.
Yeah similar in the UK. £3k for a single room mini split. £6k for a two room, etc. There's no way you're doing a whole house for less than bend-over money.
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.
Electricity monopoly in the US = they can price gouge, and this is literally the only reason I installed a dual fuel system with a less efficient heat pump. The Eversource electricity price hikes last year probably would have meant I couldn't afford to heat my home in the worst parts of winter here in Massachusetts.
This is how policies are killing the planet. Socialize electric utilities, upgrade the electric grid, subsidize the use of electric heat pumps so they're actually affordable for all end users, and of course more people would adopt them.
As it is, I run my heat pump as much as I can, which is like 9 months a year. Better than only having gas heat at least.
The US has some of the lowest electricity prices in the world though. Only a couple pennies per kWh higher than Canada. And MUCH lower than pretty much all of Europe.
In 2020 (last year I could find from Canada specifically) Canada averaged 11.25¢ per kWh. The US averaged 13.04¢. The UK averaged 21.91¢, France averaged 19.91¢, Finland 20.56¢, Spain 28.77¢, and Germany 33.39¢.
The Mitsubishi Hyper heat can work down to -13F,
The absolutely best resource I’ve found for heat pump research is the NEEP database which will you give you actual BTU outputs at various ambient temperature readings: https://ashp.neep.org/#!/product_list/

Also worth considering a geothermal heat pump depending on your geography, as then you have a guarantee of efficiency all year round
When the context is involving climate, electricity rates, and money, there is little overlap between all of the Americas. It makes sense to tighten it down to the top half (more similar climates, etc) or bottom half (electricity rates for example). Canada has the wealth and the electricity rates to make heat pumps extremely viable, and for the most part climate too. The USA shares a lot of this. The Central/South Americas do not overlap like this with Canada.
But that wouldn't be accurate because there are South American countries with even cheaper electricity than here, so it's only the cheapest in North America.
Also not to be too pedantic but central America isn't technically a continent, and it all falls under North America anyways.
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.
Makes sense to me that they could theoretically work all the way down to near 0 kelvin, just depends on their efficiency. Just so long as there is heat to be had…
They theoretically could, but the coefficient of performance would go below 1 long before you get close to zero Kelvin. That means it would cost more energy to pump the heat than is pumped, so you'd be better off using an electric heater.
Notice the effect drops dramatically below -20 C°.
But this is a pump sold for the Scandinavian market, therefore it is of course designed to work at low temperatures.
It doesn't state the minimum, but I'm guessing it would be around -40 C°. Which is very good compared top older models.
But that’s not sufficient. As the temperature gets colder, it’s not just less efficient but produces much less heat. At the lower temperatures, it may not be able to keep up. Since it would be wasteful most of the year, heat pumps aren’t sized for that
Which is why you have a backup system. I have a net zero house in Saskatchewan, Canada. My Carrier heat pump will operate to -15C, and switches to electric heating coils in the air handler if it's colder outside. It's a rather extreme climate here, but in most other places, you'd be fine with some baseboard heaters as backup.
It really depends on the type of heat pump. Air-sourced heat pumps generally don't produce heat below -30C and below -10C they generally lose enough efficiency that you're better off using electric baseboard heating.
My air sourced heat pump keeps my house warm just fine in the Finnish winter where temperatures of -30C aren't unheard of. I'm not exactly sure how it works, but I assume there's coils that'll produce the heat by electricity if nececcary, making it at worst as efficient as direct electric heating, which is what I'd use otherwise. Here like every other house has a heatpump like that and I don't remember hearing anyone ever complaining that they're not working.
Generally you'd have a backup heat source with an air-to-air heat pump for those really cold days like -15C and colder, like a gas furnace or a heating element unit inside (like with electrical coils). Air-to-air heat pumps are more efficient on warmer days, on colder days they would be less efficient but you'd still have a backup heat source so it would still "work", so the article is still somewhat correct in that sense.
Also, electric baseboard heaters can be quite a bit louder than forced-air systems with a heat pump, so you'd still be better off with a heat pump in those cases.
It just comes from a fundamental misunderstanding of how the universe operates.
They say oh well it's cold outside so how can it make it warm inside? They say this because they have absolutely no understanding of where the concept of a temperature comes from. They think that if it's 10° outside then there is 10° of energy outside presumably out to some arbitrary distance, because some places are warmer, but they don't really think that bit through. They don't realise that's not how it works.
EVs work fine in cold weather. I live in Minnesota and drive an EV. It loses about 10-20% of the total range in the winter, but most of that appears to be from generating heat for the passengers.
The problem isn’t that EVs don’t work in the winter, it’s that their range gets significantly reduced. We had issues with people literally up and abandoning their vehicles because their batteries ran flat.
In these cases the issue is less that the range is lost, and more that with snowy and cold weather traffic gets unpredictable. You can end up in long queues and that’s where the issues start.
When I went on a work trip up in the far north I never saw a single EV. Asked my colleagues about it and none of them thought EVs particularly feasible as a primary vehicle.
All that said, EVs work great for most people most of the time.
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.
That's why I said it depends on the type of the heat pump. Some can go really low, the cheaper ones not. At some point (the latest at -273.15C :D) they need to switch.
A heat pump will always generate a small amount of heat just from the compressor running, but most of the time that's a lot less energy than is being moved. As the outdoor temperature drops the delta between input and output air temp will decrease until the difference is entirely from generated heat in the compressor. Most designs would turn on extra resistive heating once the output temperature drops below your set target though. Modern designs are capable of moving a reasonable amount of heat even down to at least -25°C / -13°F now though.
It gets less effective, down to running at 100% and not moving heat. Heat pumps work by expanding a gas, which cools it. Since it's cold, the "heat" outside was the gas. Then the gas is taken inside and compressed, the gas heats up from the compression (since all the energy is squeezed into a smaller space, effectively speaking). Now that heat can be transferred to the colder air inside. So long as the expanded gas turns colder than the outside, it can absorb heat.
From a Google, common ones can go as low as - 25C, which means they are able to cool a gas to lower temps than that when expanded. There is still heat to get, even in -25C.
I can only talk for myself but I have a Nibe pump here in Sweden with air source outside pump and water heating system to radiators on the inside. Even down to -30° with really shitty windows it was enough heat for me to be comfortable. Though it did indeed use the supplementary resistive heating a bit it was still able to give me about a 200% efficiency during that period. Give a typical winter (usually around -5-10C but, as said can go down to -20C or -30C for a week or so) it still runs an average of about 300-400% efficiency.
I have an air sourced heat pump and it gets to -35C for a few weeks at time here. When it's that cold it does produce heat but your breath is hotter. There's no point in running it as it just doesn't make any kind of useful heat. Below -10C the amount of heat it produces noticeably tapers off.
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?
They are just AC units in reverse. The biggest effect humidity is going to have is on how much condensation is going to form on the exterior radiator. That'll form frost that'll have to be melted in a defrosting cycle. That'll decrease performance and efficacy. Low humidity should keep that to a minimum.
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.
This is my first comment, but since it's my job might as well:
The fact that you need a well insulated house for a heat pump is absolutely not true. What you need is a house where the expected heat loss at the design temperature can be added to the house using low temperature heating such as in floor heating. You can live in a cardboard box for all intends and purposes, if you can keep your house warm with (loads of) 35-40C water you are fine. And you would be amazed how much heat in floor heating can provide when having tubes at 10cm heart to heart distance from each other. Your energy bill will be enormous, but it would be as well if you would burn gas in a stove.
Does insulation help? Obviously. The most energy efficient, sustainable and comfortable kWh of heat is the one you don't need. Is it a requirement? Absolutely not.
Source, ex aerospace engineer that advices and installs heat pumps for residential buildings
Edit: This might differ across the pond but in the Netherlands in floor heating is super common. In America I believe this is not so much the case? Not sure.
A standard furnace works by kicking on when heat drops below the set point
So does a heat pump, and you can get Air to Water heat pumps that work almost exactly as a furnace.
The most efficient heat pumps are constantly trickling a little heat at a time, rather than cycling on and off.
Our stoker wood pellet furnace does the same if possible, it can't go below 25% capacity, because it doesn't burn right at lower capacities. So at certain temperatures, it maintains a steady state, but at others it has to turn on and off. A heat pump can easily do whatever is more efficient.
PS:
Heat pumps are similar technology to fridges, which also turn on and off depending on needs.
heat energy is heat energy, where you get it from doesn't matter, if your house isn't well insulated the heat loss will be the same regardless what pumps in the heat.
The home is a container for heat. If it is a poorly insulated container the heat pump does not put out enough BTUs to keep the house warm because the heat is escaping faster than it can be generated.
It seems to me like you're describing the genetic problem of having an undersized heating system, not anything specific to heat pumps. I'm positive heat pumps exist that are equal in capacity to whatever furnace you have.
It does sound like in your case improving your house's insulation would be a better investment than installing a new heating system though.
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.
For those reading wondering if this guy knows what he's talking about, he says that electric furnaces are "hilariously inefficient". They were in fact the most efficient option before heat pumps - more efficient than the most efficient gas furnaces. Electricity is expensive, so depending on the situation, it may cost more than inefficiently burning super cheap gas, but calling electric heating "hilariously inefficient" demonstrates a severe lack of knowledge of the area. So, with that in mind, consider whether anything else claimed here is worth retaining.
I think it's just a matter of what you're comparing.
Heat pumps are ridiculously "efficient" in terms of operation (like 200% efficient, etc. etc. etc.)
But from what I am seeing with them they are claiming efficiency as "is it smarter to run an electric heat pump vs. a gas furnace" for your money. In that sense, a heat pump can be super efficient but still not as "efficient" for your wallet compared to a gas furnace given how much cheaper gas is (in the states that is.) Someone else commented that even after all the rebates and everything else, it would take >20 years to reach a payoff in terms of buying a heat pump vs a standard gas furnace. That timeline is generally outside what a typical homeowner looks at here.
I mean- you even acknowledge you pick up what they're saying so...?
Perhaps we should set new terms like "operational efficiency" which is for the most part indisputable and "monetary efficiency" which is fluid and can definitely be varied around a single country, let alone the globe.
It(electric furnaces) may not be as efficient in terms of how much money you have to spend to keep your house warm, and obviously this is the efficiency most people will care about because we are not Jeff Bezos with his deep pockets