In upstate NY an air source heat pump is not viable but ground source heat pumps are fine. If you go south a bit, say to North Carolina, the air source heat pump looks like a good idea.
Either way the capital cost of a heat pump is high and people seem to have a psychological aversion to spending money on capital costs.
One of the best selling points of a heat pump is comfort: it switches continuously from heating to air conditioning. An eco-sensitive person in Upstate NY might not really think they need air conditioning. It's not like buying a Toyota Corolla to save the planet, it's more like buying a Cadillac Escalade to save the planet and the psychology doesn't really work for that.
I'm not used to think of ground source systems as simply heat pumps... I think of them as geothermal systems. Maybe because the installation is lot more involved.
But in places like Florida, if you have a 15+ year old A/C, replacing it with a conventional modern heat pump, it would probably pay for itself in a few years.
Newer refrigerant and designs for air source heat pumps are a lot more cold weather capable than many people think. Quite a few installations are more efficient than resistive heating down to around -13 F / -25 C and don't need a defrost cycle.
Plenty of places get or stay colder than -25C, but that is often short stretches or overnight. There are a lot of places that would do better with a little resistive heat backup compared to the huge installation costs for ground source.
New neighbourhoods in cold climates should be required to install community ground source heat pumps. Since all that dirt is moving anyway the cost of trenching is negligible and any drilling is amortized over many properties.
All utilities will be much cheaper if they are amortized over many properties.
Heat pump capital costs are too high. They should be standardized or designed to be cheap and used everywhere…to recover waste heat from everywhere in the home.
Air source heat pumps don't cost significantly differently from gas furnaces or boilers, especially once you account for running costs. Anyone with A/C already has an air source heat pump, just one that only moves heat from inside the house to outside. Moving heat in both directions take some extra valves and an extra heat exchanger, but this doesn't dramatically increase costs. The basic principal and components are exactly the same.
Ground source is expensive, but that's due to drilling and/or trenching. The actual heat pump is a tiny fraction of the bill to install ground source heating.
I'm interested in air/water heat pumps for slab heating[0]. In the summer they can be reversed to provide cooling, so long as you keep the slab zone above the dewpoint and provide additional wall-mounted exchangers in other zones as needed.
in Sweden we use them a lot. Most of the time they work really well and it's not like they are useless just because it gets really cold. They still help a lot even if the traditional heater element might need to kick in for short periods. It's usually not until 20 below freezing that they don't add much, but those temperatures are not a daily occurrence for most of us.
"One of the most common complaints about heat pumps, experts said, was that they would stop providing heat on very cold days. But advances to heat pump compressors have made them more efficient, cost effective and successful at providing heat in colder temperatures."
Yeah this is a key issue that shouldn't be glossed over like this. We need more data about how much they have improved.
My heat pump has what they call "Emergency Heat" which is basically just some heating coils they add in like a traditional electric furnace. So on days when the heat pump can't do it's thing, it works just like the old furnace that I replaced. Emergency heat also kicks on when the differential between the current temp and desired temp is large. 99% of the time, the heat pump seems to do just fine on it's own.
Newer heat pumps still have electric heat, but also can extract heat from ambient air down to -10F. Mr Cool for the DIYer, Mitsubishi for the workhorse. Reverser valves do the work of switching heat pumping direction.
I suspect that most of the reluctance comes from people using gas furnaces, not people using electrical resistance heating. Compared to electrical resistance heating, a heat pump has no downsides other than a higher initial cost which is very quickly paid back from energy savings, since electrical resistance heating is staggeringly expensive.
Resistive heat is staggeringly expensive to operate in cold climates and the people most often using it are renters who have no choice. The heat pump law and subsidy I'd most like to see is for retrofitting rental units with heat pumps, especially in places where the renter is paying for utilities. Make sure the landlord can't block the improvement (or force them to do it and cover some costs).
I like carbon pricing in theory as a market solution, but it really only works when the person paying the extra cost can make different choices about their usage. Those of us rich, old, or lucky enough to own homes can retrofit for efficiency as we see fit. Renters are stuck with whatever heat source, air sealing, and insulation they draw in the lottery, especially in the current housing crunch. If the renter is also paying the utilities the person with the carbon-pricing incentive to make improvements isn't allowed to and the landlord has no reason to change.
My parent tried heat pumps twice. They are incapable of even handling the usually not-very-severe winters of central Texas without resorting to turning on their pathetically weak resistance heaters, an those can cost nearly $100/day to run! Their second Gen system was much newer and more expensive, but not much better.
The definitely are not capable of handling any subfreezing temperatures. Natural gas is, overall, FAR more efficient for heating when the supposed efficiency of the heat pump gets slammed by the inefficiency of electric heat.
So that answers the OP's question of why we don't use them: They're fiddly, expensive to buy, and both don't work in, and are insanely expensive to operate in the cold.
That's not been my experience and I live north of 46 degrees latitude, with an average December temperatures much lower than, for example, Abilene, TX, with a total electric bill in the neighborhood of ~$250/month in December/January. The Coefficient of Performance for electrical resistance heat, and natural gas are both 1.0, (so you need the same number of joules to heat the air to the same temperature from either energy source). Maybe electric rates are really high in Texas in the winter? Or the gas rates are really low, and the house is huge?
Is it possible your parent's house is not well insulated/sealed? Potentially _really_ uninsulated? I've talked to people here (45 degrees latitude) who are happily using their heat pumps and we're looking at models for ourselves. One caveat being the people I'm talking to live in above average performance homes (in terms of insulation and air sealing).
For a video that glosses over the details but loudly proclaims this “ugly truth” there’s this one. I can’t tell if he is a paid shill for the gas industry or just obtuse, or maybe a voice of common sense in the wilderness….
Speaking from the UK. We had 2 days of hot weather. A reasonably insulated house or one with decent thermal mass is fine.
Heat pumps are more use here for the heat, we don't have extreme winters, so the basic premise of the article from a UK perspective is wrong. Plus the name 'heat pump' doesn't indicate a direction anyway.
I think the issue in the UK is that the majority of houses are simply not good isolated. A heat pump needs to pump into an isolated house or it will not be very efficient.
> the British government has provided grant money to a little-known solution: heat pumps.
What the hell? Heat pumps are not little known. An air conditioner is a heat pump. It's hard to take the article seriously when they gloss over this basic fundamental point.
I can tell they're trying to advocate for something, perhaps using the heat wave as a push to install larger bidirectional heat pumps that will make Europe less dependent on natural gas come winter? Still the whole framing just comes across as odd... like "Local area man stays cool with this one simple trick" [install an air conditioner]
Heatpumps are great! Having a coefficient of performance equal to 4 (1kW electricity to 4kW heat) is possible today!
Unfortunately it is not as easy as just switching your gas heating with a heatpump.
For one, heatpumps have a lower flow temperature, therefore a good insulation of the house is required. Also big radiators such as floor or wall are preferred.
Moving to heatpumps might start an entire house renovation which comes at a cost.
In New Zealand heatpumps are the norm, and have been for 20+ years. But culturally wood burning is another norm. So we have this werid combination of wood burners in the same room as high powered heatpumps because people want the feel of radiated heating.
Most cities here require low or ultra low emission burners, which burn at high temperature, so often the temperature is kept low.
And you are absolutely correct about venting heat. I have not to my knowledge seen a home here with an externally ducted air source. So the room is heated, and heat (warm air) is sucked out of the rest of the house.
Wood is cheap here, and so people often believe it is more efficient jot counting the inefficiencies of wood.
I wonder when the heat pump technology will be so widespread/standardized that I can for example buy a refrigerator and connect a couple pipes so that instead of releasing heat into the kitchen I can transfer that heat to warm water for a shower.
Also, using washing machines flushing water to fill a bigger tanks later accessed by the house's toilet tanks should be standard procedure.
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[ 3.2 ms ] story [ 95.7 ms ] threadEither way the capital cost of a heat pump is high and people seem to have a psychological aversion to spending money on capital costs.
One of the best selling points of a heat pump is comfort: it switches continuously from heating to air conditioning. An eco-sensitive person in Upstate NY might not really think they need air conditioning. It's not like buying a Toyota Corolla to save the planet, it's more like buying a Cadillac Escalade to save the planet and the psychology doesn't really work for that.
See https://energysavingtrust.org.uk/air-source-heat-pumps-vs-gr...
But in places like Florida, if you have a 15+ year old A/C, replacing it with a conventional modern heat pump, it would probably pay for itself in a few years.
Plenty of places get or stay colder than -25C, but that is often short stretches or overnight. There are a lot of places that would do better with a little resistive heat backup compared to the huge installation costs for ground source.
New neighbourhoods in cold climates should be required to install community ground source heat pumps. Since all that dirt is moving anyway the cost of trenching is negligible and any drilling is amortized over many properties.
Heat pump capital costs are too high. They should be standardized or designed to be cheap and used everywhere…to recover waste heat from everywhere in the home.
Ground source is expensive, but that's due to drilling and/or trenching. The actual heat pump is a tiny fraction of the bill to install ground source heating.
[0] https://www.chiltrix.com/chiller-technology.html
Yeah this is a key issue that shouldn't be glossed over like this. We need more data about how much they have improved.
I like carbon pricing in theory as a market solution, but it really only works when the person paying the extra cost can make different choices about their usage. Those of us rich, old, or lucky enough to own homes can retrofit for efficiency as we see fit. Renters are stuck with whatever heat source, air sealing, and insulation they draw in the lottery, especially in the current housing crunch. If the renter is also paying the utilities the person with the carbon-pricing incentive to make improvements isn't allowed to and the landlord has no reason to change.
Heat pumps have "emergency" electrical resistance heaters for this. Source: owned homes with heat pumps for the past 20 years.
The definitely are not capable of handling any subfreezing temperatures. Natural gas is, overall, FAR more efficient for heating when the supposed efficiency of the heat pump gets slammed by the inefficiency of electric heat.
So that answers the OP's question of why we don't use them: They're fiddly, expensive to buy, and both don't work in, and are insanely expensive to operate in the cold.
https://youtu.be/GhAKMAcmJFg
https://youtu.be/7J52mDjZzto
One of the best things is that is an air conditioner you run in reverse to get some heating.
What the hell? Heat pumps are not little known. An air conditioner is a heat pump. It's hard to take the article seriously when they gloss over this basic fundamental point.
I can tell they're trying to advocate for something, perhaps using the heat wave as a push to install larger bidirectional heat pumps that will make Europe less dependent on natural gas come winter? Still the whole framing just comes across as odd... like "Local area man stays cool with this one simple trick" [install an air conditioner]
Unfortunately it is not as easy as just switching your gas heating with a heatpump. For one, heatpumps have a lower flow temperature, therefore a good insulation of the house is required. Also big radiators such as floor or wall are preferred.
Moving to heatpumps might start an entire house renovation which comes at a cost.
The problem with wood fires is they require a ducted external air source, or the chimney will exhaust your expensive heated air.
And you are absolutely correct about venting heat. I have not to my knowledge seen a home here with an externally ducted air source. So the room is heated, and heat (warm air) is sucked out of the rest of the house.
Wood is cheap here, and so people often believe it is more efficient jot counting the inefficiencies of wood.