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Wow, I was not even aware this myth was a thing. I'm thoroughly confused. Here in northern Sweden, geothermal heat pumps are seen as pretty much the only viable

by einr 3y ago

Wow, I was not even aware this myth was a thing. I'm thoroughly confused. Here in northern Sweden, geothermal heat pumps are seen as pretty much the only viable option for houses that aren't connected to district heating. We get -25 degrees in winter here and it's simply a non-issue. Heat pumps are so dramatically cheaper and more efficient than any other option in cold climates that no one even considers installing electric radiators or oil/gas furnaces. The only other real option that people actually use is a wood or wood pellet furnace. It feels like near enough every home owner I talk to either has or is planning to drill for a geothermal heat pump. Air-air heat pumps are popular too for secondary spaces like garages or if you're on a tight budget. The top five countries in terms of heat pumps per capita all being in northern Europe* should tell you something about this myth: 1. Norway 2. Finland 3. Sweden 4. Estonia 5. Denmark * https://www.theecoexperts.co.uk/heat-pumps/top-countries https://www.theecoexperts.co.uk/heat-pumps/top-countries

jfengel 3y ago
Here in the mid-Atlantic, my air-air heat pump struggles once things get well below freezing. Which it does a few days a year. On those days, there's a backup resistance heater. Which is vastly more expensive, but since it's only run on occasion, it wouldn't be worth it install a geothermal heat pump. I would love to, but the additional cost is tens of thousands of dollars. The since the alternative costs perhaps a couple of hundred dollars per year, the time to breakeven is many decades. It's still quite clear that a heat pump is a very good all-electric option, especially since it provides cooling in the summer. Which is absolutely mandatory around here, and will get more and more so over the years. Which, ironically, will also reduce the use of the resistance heater from "very rare" to "practically never".
- bjornasm 3y ago
  Why/how does it struggle?
- ilyt 3y ago
  The new propane or CO2-based pumps the temperature it keeps working is also lower so it isn't much of a problem for most places if you are in market for one currently.
- bobchadwick 3y ago
  What type of heat pump do you have? I have a ducted split system with a HSPF of 9.5, and I'm actually pretty disappointed with how it performs. In our new-ish, better-than-average insulated house, we've had some insane electrical bills over the last couple winters compared to the gas bills we had in previous years (prior to renovating). Sometimes I wonder if the installer didn't really know what he was doing.
  - petre 3y ago
    What heating elements or output temperature are you runnng your HP at, and do you have buffer storage or not?
    - bobchadwick 3y ago
      It's an air-air ducted system. I live in the North East US, so winters are generally cold, with a few days around 0F/-17C. During heating season we keep it at 67F/19C.
      - petre 3y ago
        That's a COP of 2.8. You have to check the efficiency graph and your mean winter temperatures, because I suspect it operates fully resistive at below -10°C or so. I also noted underwhelming performance and increased faulty compressor incidence for air source heat pumps with the external unit mounted on Northern walls (in the Northern hemisphere). I suspect it doesn't get sunshine and the defreezing resistive element is operating a lot, driving up energy costs.
- dkjaudyeqooe 3y ago
  How old is your aircon? I bought some cheap Chinese "mini split" 3.5kW units locally for about 350 euros that go down to about -15 at about 2.5x effective heating to input (watts). They're closer to 4x at higher temps. Cooling runs at about 7x. Aircons have become much cheaper and more effective over time. It might be worth looking at replacing your unit, assuming it's not something much more elaborate.
  - jfengel 3y ago
    Old enough that I'm not gonna say out of sheer superstition. Old enough to raise eyebrows on the repair guy. When it finally has to be replaced the new one will assuredly be more efficient. But since it's already quite cheap to run (the very most expensive bill is perhaps $200 during a very hot August with me working from home), I'd love for this one to keep going as long as possible.
    - dkjaudyeqooe 3y ago
      I'm cooling an approx 30m2 apartment with brick (cinder block) walls that are not insulated and I run the aircon continuously 24/7 all summer and use about 200kWh per month (approx $35 for me). Daytime temps are usually between 31 and 37 celsius and nighttime around 21 to 25.
- throw0101a 3y ago
  > Here in the mid-Atlantic, my air-air heat pump struggles once things get well below freezing. Which it does a few days a year. How far north are you (IECC climate zone)? What is the make and model of your unit? Is it a cold climate air-source heap pump (ccASHP)? * https://ashp.neep.org/#!/ https://ashp.neep.org/#!/ * https://neep.org/heating-electrification/ccashp-specification-product-list https://neep.org/heating-electrification/ccashp-specificatio... Because there are folks in Climate Zone 7 in the northern tip of Maine (Caribou) that use heat pumpss * https://www.youtube.com/watch?v=OcwIz6heDss&t=43m21s https://www.youtube.com/watch?v=OcwIz6heDss&t=43m21s Mitsubishis can work down to -13F/-25C and still have a COP of 2.08 (1=resistive heating): * https://www.mitsubishicomfort.com/articles/keep-warm-this-winter-inverter-technology-for-any-climate https://www.mitsubishicomfort.com/articles/keep-warm-this-wi... * https://mylinkdrive.com/viewPdf?srcUrl=http://enter.mehvac.com.s3.amazonaws.com/DAMRoot/Original/10006%5CM_SUBMITTAL_MSZ-FS12NA_MUZ-FS12NA_en.pdf https://mylinkdrive.com/viewPdf?srcUrl=http://enter.mehvac.c...
  - DiabloD3 3y ago
    I live in Maine, but not as far north as Caribou. The units we use up here will work flawlessly down to about 10f, and keep working until approximately -20f. Thanks to climate change, I haven't seen -20f at night in several years, but the last time it happened, the heat pump struggled to keep my house warm but still managed to do it. "Most" of Canada only gets about this cold, where "most" is the majority of the population that lives near the border.
- PaulDavisThe1st 3y ago
  THere's something wrong with your heat pump, or you needed/need a different unit. I live in New Mexico @ 6000', I have Mitsubishi Hyper units, and it has to get down to below 10 degrees before you can even see any difference in the heat pumps' operation. Even so, they still get the house up to temperature, just takes a bit longer. The difference in cost over regular Mitsubishi's was low single digit thousands.
stdbrouw 3y ago
But geothermal heat pumps are interesting in cold climates because air-air and air-water heat pumps (the most common and affordable types) are less efficient below freezing, so I feel like that confirms rather than dispels the myth!
- einr 3y ago
  Air-air heat pumps have gotten a lot better in the last 10-20 years and a modern one by a reputable brand will absolutely still work at Nordic winter temperatures. People buy those too, but not generally to heat entire houses. Air-water is not popular here, I know they exist on the market and some people probably have them but I don't think I've ever seen one.
- bjornasm 3y ago
  My air-air heat pump works down to -13 fahrenheit. Its less efficient but still more than efficient enough to heat my house, and more economic than anything else when its below freezing.
paiute 3y ago
Geothermal is very different than air. In my state that hole will run you about 20k alone, if they let you drill it the first place. I have an air-air heat pump and i hate it, mostly due to air flow issues, but they really don’t work well in low temps.
- einr 3y ago
  It runs you $20k here too (well, the hole plus the pump plus installation is about 20k) but still pretty much everyone does it, because it's so dramatically more efficient that you're going to make that money back before the pump is toast -- and when it is, it's much cheaper to upgrade to a new one because you already have the hole ;)
- bjornasm 3y ago
  Yes they do. I have no idea what heat pumps you have, but air-air heat pumps can be found in every other house here in Norway.
  - windexh8er 3y ago
    My main unit (live in the northern part of the central US) can operate below -10F with no problem heating my house. It is a dual fuel system (natural gas + HP) and, normal operations I don't, normally, run the pump at those temps. I generally lock the HP out around 10F and let the system choose the heat source based on the conditions. Air source heat pumps are very viable in the northern climates of the US.
hotnfresh 3y ago
In the '00s, HVAC people in my area of the US were recommending against heat pumps because they'd not be able to run in heat-pump mode enough to make it worth it, and they were more complex, so had more ways to fail. And more expensive up-front, since you'd still have to have a furnace anyway and they were pricier than a plain central AC unit of similar size. Ones I spoke to said the new houses installing them and touting the energy efficiency to buyers were all under-sizing and those folks were going to have really crappy heating and cooling until they eventually replace the units (but, to be fair, new construction also tends to under-size furnaces and regular AC). From what I could tell, they were mostly right about all that. You'd be lucky to break even on overall costs if you went with a heat pump in that decade. The ones that weren't crazy-expensive only worked down to (IIRC) 20F or something like that, and we just had too many days under that in a year for it to make much sense. Newer ones are better, but I bet "heat pumps are a scam" remains an attitude in many circles, because at one point they kinda were. At least in our climate. Other countries may have had bigger government incentives that offset the costs of higher-end heat pumps back then so the economics worked out better, I dunno, but we didn't. [EDIT] Air-air, that is. Practically nobody does geothermal heat pumps here. The up-front cost is waaaaaay higher than any kind of normal (for us) set-up, not many people do it so that makes the cost even higher because the installation market is tiny, and energy costs aren't high enough to make the extra tens of thousands of dollars a good investment.
- windexh8er 3y ago
  > Practically nobody does geothermal heat pumps here. The up-front cost is waaaaaay higher than any kind of normal (for us) set-up, not many people do it so that makes the cost even higher because the installation market is tiny, and energy costs aren't high enough to make the extra tens of thousands of dollars a good investment. This isn't true in all parts of the US. A family member of mine has had an open loop geo-thermal system for almost a decade now, and they're definitely not the only one in the area. I'd say about half of my neighborhood has air source heat pumps and about a quarter of the remaining have geo-thermal (vertical loops). There are two HVAC businesses in my area that specialize in nothing but ground source heat pumps. If there was no market, they'd be out of business. I think, where I am, it's harder to find a cognizant air source installer. Most of the HVAC businesses here are still under the misconception that air source isn't viable in our northern locale and often don't try to sell, or try to talk people out of them. But my air source is able to heat our house easily at 0F and is rated to run below -10F. It's currently my main heat source. Over the course of winter I'd guesstimate 60-70% heat pump heating overall.
synecdoche 3y ago
Historically electrically powered convection radiators were very common in northern Sweden and plenty of one-family houses still have them. Perhaps their relative inefficiency was good enough in earlier times when power in northern Sweden was very cheap. Nowadays it wouldn’t make much sense to install them. Both because electricity is more expensive and there are more efficient options.
thsksbd 3y ago
"...geothermal heat pumps" There's your answer, isnt it? With geothermal it doesn't really matter how cold it gets outside. But you have to dig a really deep hole, fill it with pipes and refrigerant, and offer sacrifices to Thor so that the pipes never leak. The "myth" in the US refers to air-air heat pumps which do have a significant degradation is performance as it gets colder.
- brtkdotse 3y ago
  Not necessarily. There’s also something called air-to-water heatpumps which work like a mix of geothermal and air-to-air. My house (~1900sqf/200m2) is currently warmed up by a 10kW Nibe 2025 that’s connected to a 300L buffer tank. It does it by its own down to -5C, after which a 3kW resistance heater in the tank adds the missing effect. During the winter it uses ~1000-1500kWh for both heat and warm water.
  - rayiner 3y ago
    We don’t have those in the US either.
  - jpfr 3y ago
    I have a heat pump that used 200 kWh of electricity in a single day! Granted, it was the coldest day of the winter. Is your house especially insulated to get that low?
    - ReptileMan 3y ago
      I think that in Europe traditional building materials - like bricks are natural insulators and our modern glass panels are 3 layers by default. So it may come as normal house in Europe is especially insulated in US. 200 kwh is quite a lot ... but also in US it looks like that the houses are bigger.
    - 8fingerlouie 3y ago
      Not OP, but 200 kWh sounds like A LOT. I have a 7 kWh Vaillant Heat Pump in Denmark, and the highest consumption i saw last winter was just over 60 kWh per day, which was with -16C. My total consumption for a year with heat and hot water was around 3600 kWh ( 2200 ft2, 4 people). COP was around 3.7 on average for the entire year, so ~13,500 kWh of heat produced by the heat pump. For comparison, one m3 of natural gas is around 10.5 kWh of heat, so we produced the equivalent of 1,285 m3 of gas.

by einr 3y ago

jfengel 3y ago

Here in the mid-Atlantic, my air-air heat pump struggles once things get well below freezing. Which it does a few days a year. On those days, there's a backup resistance heater. Which is vastly more expensive, but since it's only run on occasion, it wouldn't be worth it install a geothermal heat pump. I would love to, but the additional cost is tens of thousands of dollars. The since the alternative costs perhaps a couple of hundred dollars per year, the time to breakeven is many decades. It's still quite clear that a heat pump is a very good all-electric option, especially since it provides cooling in the summer. Which is absolutely mandatory around here, and will get more and more so over the years. Which, ironically, will also reduce the use of the resistance heater from "very rare" to "practically never".

bjornasm 3y ago
Why/how does it struggle?
ilyt 3y ago
The new propane or CO2-based pumps the temperature it keeps working is also lower so it isn't much of a problem for most places if you are in market for one currently.
bobchadwick 3y ago
What type of heat pump do you have? I have a ducted split system with a HSPF of 9.5, and I'm actually pretty disappointed with how it performs. In our new-ish, better-than-average insulated house, we've had some insane electrical bills over the last couple winters compared to the gas bills we had in previous years (prior to renovating). Sometimes I wonder if the installer didn't really know what he was doing.
- petre 3y ago
  What heating elements or output temperature are you runnng your HP at, and do you have buffer storage or not?
  - bobchadwick 3y ago
    It's an air-air ducted system. I live in the North East US, so winters are generally cold, with a few days around 0F/-17C. During heating season we keep it at 67F/19C.
    - petre 3y ago
      That's a COP of 2.8. You have to check the efficiency graph and your mean winter temperatures, because I suspect it operates fully resistive at below -10°C or so. I also noted underwhelming performance and increased faulty compressor incidence for air source heat pumps with the external unit mounted on Northern walls (in the Northern hemisphere). I suspect it doesn't get sunshine and the defreezing resistive element is operating a lot, driving up energy costs.
dkjaudyeqooe 3y ago
How old is your aircon? I bought some cheap Chinese "mini split" 3.5kW units locally for about 350 euros that go down to about -15 at about 2.5x effective heating to input (watts). They're closer to 4x at higher temps. Cooling runs at about 7x. Aircons have become much cheaper and more effective over time. It might be worth looking at replacing your unit, assuming it's not something much more elaborate.
- jfengel 3y ago
  Old enough that I'm not gonna say out of sheer superstition. Old enough to raise eyebrows on the repair guy. When it finally has to be replaced the new one will assuredly be more efficient. But since it's already quite cheap to run (the very most expensive bill is perhaps $200 during a very hot August with me working from home), I'd love for this one to keep going as long as possible.
  - dkjaudyeqooe 3y ago
    I'm cooling an approx 30m2 apartment with brick (cinder block) walls that are not insulated and I run the aircon continuously 24/7 all summer and use about 200kWh per month (approx $35 for me). Daytime temps are usually between 31 and 37 celsius and nighttime around 21 to 25.
throw0101a 3y ago
> Here in the mid-Atlantic, my air-air heat pump struggles once things get well below freezing. Which it does a few days a year. How far north are you (IECC climate zone)? What is the make and model of your unit? Is it a cold climate air-source heap pump (ccASHP)? * https://ashp.neep.org/#!/ https://ashp.neep.org/#!/ * https://neep.org/heating-electrification/ccashp-specification-product-list https://neep.org/heating-electrification/ccashp-specificatio... Because there are folks in Climate Zone 7 in the northern tip of Maine (Caribou) that use heat pumpss * https://www.youtube.com/watch?v=OcwIz6heDss&t=43m21s https://www.youtube.com/watch?v=OcwIz6heDss&t=43m21s Mitsubishis can work down to -13F/-25C and still have a COP of 2.08 (1=resistive heating): * https://www.mitsubishicomfort.com/articles/keep-warm-this-winter-inverter-technology-for-any-climate https://www.mitsubishicomfort.com/articles/keep-warm-this-wi... * https://mylinkdrive.com/viewPdf?srcUrl=http://enter.mehvac.com.s3.amazonaws.com/DAMRoot/Original/10006%5CM_SUBMITTAL_MSZ-FS12NA_MUZ-FS12NA_en.pdf https://mylinkdrive.com/viewPdf?srcUrl=http://enter.mehvac.c...
- DiabloD3 3y ago
  I live in Maine, but not as far north as Caribou. The units we use up here will work flawlessly down to about 10f, and keep working until approximately -20f. Thanks to climate change, I haven't seen -20f at night in several years, but the last time it happened, the heat pump struggled to keep my house warm but still managed to do it. "Most" of Canada only gets about this cold, where "most" is the majority of the population that lives near the border.
PaulDavisThe1st 3y ago
THere's something wrong with your heat pump, or you needed/need a different unit. I live in New Mexico @ 6000', I have Mitsubishi Hyper units, and it has to get down to below 10 degrees before you can even see any difference in the heat pumps' operation. Even so, they still get the house up to temperature, just takes a bit longer. The difference in cost over regular Mitsubishi's was low single digit thousands.

stdbrouw 3y ago

But geothermal heat pumps are interesting in cold climates because air-air and air-water heat pumps (the most common and affordable types) are less efficient below freezing, so I feel like that confirms rather than dispels the myth!

einr 3y ago
Air-air heat pumps have gotten a lot better in the last 10-20 years and a modern one by a reputable brand will absolutely still work at Nordic winter temperatures. People buy those too, but not generally to heat entire houses. Air-water is not popular here, I know they exist on the market and some people probably have them but I don't think I've ever seen one.
bjornasm 3y ago
My air-air heat pump works down to -13 fahrenheit. Its less efficient but still more than efficient enough to heat my house, and more economic than anything else when its below freezing.

paiute 3y ago

Geothermal is very different than air. In my state that hole will run you about 20k alone, if they let you drill it the first place. I have an air-air heat pump and i hate it, mostly due to air flow issues, but they really don’t work well in low temps.

einr 3y ago
It runs you $20k here too (well, the hole plus the pump plus installation is about 20k) but still pretty much everyone does it, because it's so dramatically more efficient that you're going to make that money back before the pump is toast -- and when it is, it's much cheaper to upgrade to a new one because you already have the hole ;)
bjornasm 3y ago
Yes they do. I have no idea what heat pumps you have, but air-air heat pumps can be found in every other house here in Norway.
- windexh8er 3y ago
  My main unit (live in the northern part of the central US) can operate below -10F with no problem heating my house. It is a dual fuel system (natural gas + HP) and, normal operations I don't, normally, run the pump at those temps. I generally lock the HP out around 10F and let the system choose the heat source based on the conditions. Air source heat pumps are very viable in the northern climates of the US.

hotnfresh 3y ago

In the '00s, HVAC people in my area of the US were recommending against heat pumps because they'd not be able to run in heat-pump mode enough to make it worth it, and they were more complex, so had more ways to fail. And more expensive up-front, since you'd still have to have a furnace anyway and they were pricier than a plain central AC unit of similar size. Ones I spoke to said the new houses installing them and touting the energy efficiency to buyers were all under-sizing and those folks were going to have really crappy heating and cooling until they eventually replace the units (but, to be fair, new construction also tends to under-size furnaces and regular AC). From what I could tell, they were mostly right about all that. You'd be lucky to break even on overall costs if you went with a heat pump in that decade. The ones that weren't crazy-expensive only worked down to (IIRC) 20F or something like that, and we just had too many days under that in a year for it to make much sense. Newer ones are better, but I bet "heat pumps are a scam" remains an attitude in many circles, because at one point they kinda were. At least in our climate. Other countries may have had bigger government incentives that offset the costs of higher-end heat pumps back then so the economics worked out better, I dunno, but we didn't. [EDIT] Air-air, that is. Practically nobody does geothermal heat pumps here. The up-front cost is waaaaaay higher than any kind of normal (for us) set-up, not many people do it so that makes the cost even higher because the installation market is tiny, and energy costs aren't high enough to make the extra tens of thousands of dollars a good investment.

windexh8er 3y ago
> Practically nobody does geothermal heat pumps here. The up-front cost is waaaaaay higher than any kind of normal (for us) set-up, not many people do it so that makes the cost even higher because the installation market is tiny, and energy costs aren't high enough to make the extra tens of thousands of dollars a good investment. This isn't true in all parts of the US. A family member of mine has had an open loop geo-thermal system for almost a decade now, and they're definitely not the only one in the area. I'd say about half of my neighborhood has air source heat pumps and about a quarter of the remaining have geo-thermal (vertical loops). There are two HVAC businesses in my area that specialize in nothing but ground source heat pumps. If there was no market, they'd be out of business. I think, where I am, it's harder to find a cognizant air source installer. Most of the HVAC businesses here are still under the misconception that air source isn't viable in our northern locale and often don't try to sell, or try to talk people out of them. But my air source is able to heat our house easily at 0F and is rated to run below -10F. It's currently my main heat source. Over the course of winter I'd guesstimate 60-70% heat pump heating overall.

synecdoche 3y ago

Historically electrically powered convection radiators were very common in northern Sweden and plenty of one-family houses still have them. Perhaps their relative inefficiency was good enough in earlier times when power in northern Sweden was very cheap. Nowadays it wouldn’t make much sense to install them. Both because electricity is more expensive and there are more efficient options.

thsksbd 3y ago

"...geothermal heat pumps" There's your answer, isnt it? With geothermal it doesn't really matter how cold it gets outside. But you have to dig a really deep hole, fill it with pipes and refrigerant, and offer sacrifices to Thor so that the pipes never leak. The "myth" in the US refers to air-air heat pumps which do have a significant degradation is performance as it gets colder.

brtkdotse 3y ago
Not necessarily. There’s also something called air-to-water heatpumps which work like a mix of geothermal and air-to-air. My house (~1900sqf/200m2) is currently warmed up by a 10kW Nibe 2025 that’s connected to a 300L buffer tank. It does it by its own down to -5C, after which a 3kW resistance heater in the tank adds the missing effect. During the winter it uses ~1000-1500kWh for both heat and warm water.
- rayiner 3y ago
  We don’t have those in the US either.
- jpfr 3y ago
  I have a heat pump that used 200 kWh of electricity in a single day! Granted, it was the coldest day of the winter. Is your house especially insulated to get that low?
  - ReptileMan 3y ago
    I think that in Europe traditional building materials - like bricks are natural insulators and our modern glass panels are 3 layers by default. So it may come as normal house in Europe is especially insulated in US. 200 kwh is quite a lot ... but also in US it looks like that the houses are bigger.
  - 8fingerlouie 3y ago
    Not OP, but 200 kWh sounds like A LOT. I have a 7 kWh Vaillant Heat Pump in Denmark, and the highest consumption i saw last winter was just over 60 kWh per day, which was with -16C. My total consumption for a year with heat and hot water was around 3600 kWh ( 2200 ft2, 4 people). COP was around 3.7 on average for the entire year, so ~13,500 kWh of heat produced by the heat pump. For comparison, one m3 of natural gas is around 10.5 kWh of heat, so we produced the equivalent of 1,285 m3 of gas.