112 comments

[ 2.8 ms ] story [ 163 ms ] thread
The headline doesn't match the article: of the three people interviewed, the first loved it, but taxpayers paid for hers. The second liked it, but doesn't know if he'll ever make the money back, and the third didn't like it.
This (at least the headline) reads like an advertisement for heat pump systems.

I doubt that anyone has calculated the total cost of owning and operating such a system. It might pay off in a super modern highly insulated home. Otherwise, good luck with these systems. The high upfront and maintenance cost and the expected lifetime of about 15 years make this look like a very questionable proposition to me.

+ it adds to the cost of new developments in the countries where its mandatory a high efficiency rating, like Ireland BER

https://www.seai.ie/home-energy/building-energy-rating-ber/

https://www.gov.ie/en/publication/1ca53-new-energy-efficienc...

By the way there's talk from some gov officials to forbid selling old houses if the BER rating is too low. You will need to spend thousands to get it to some better rating.

Listed houses should get an exemption to install double glazed windows and other insulation upgrades. Or they should get a discount on energy costs.
Or get subventions for insulation upgrades?
The climate in the UK may be too warm to see the real benefits. Heat pumps have been popular in the Finland for 15+ years. The calculations vary from situation to situation, but the rule of thumb is that the initial investment pays itself back in ~5 years, and you have to replace the heat pump after ~15 years.
5 years look for me highly unexpected. Can you please detail the pump type and whether you get subventions for it?
(comment deleted)
This number is more or less the same in Norway as well for air-to-air pumps without subsidies. Keep in mind that oil/gas heating and such is not normal, we've used electricity and firewood for heating for the most part. So replacing electric heaters with a heat pump will drastically reduce electricity costs, improve air quality and improve heating. Really a no brainer.
Ok that makes sense then. Most people here will compare against an existing gas or oil heating installation I guess...
That's what news articles and the companies installing heat pumps have been saying since ~2005. Had those estimates been substantially wrong, we'd know it by now.

The only subsidy is the deduction for hiring household help. If you hire outside help for any purpose, you get a tax deduction based on the wages you pay.

We did, or rather received such calculations from the providers. Today and here, depending when you retire and what your plans after that are, you might think twice about getting a geothermal one. The air-water would fit as the 1:1 replacement for the oil heating we have, with the promise of barely breaking even. NB: when you replace/upgrade an existing pump, some costs won't come again.
> We did, or rather received such calculations from the providers.

Well, the calculations from the providers are highly likely to be "optimized". I would suggest the first point one might check is if the given COP is realistic. Usually it isn't.

Wouldn't it take longer to pay off on a well-insulated home? That's the sort of home that doesn't use much gas to begin with.
1) Good insulation means you can use a smaller (cheaper) heat pump. Or it doesn't need to work hard most of the time & is therefore likely to last longer.

2) Having that heat pump removes the need for a natural gas hookup - and fixed-rate monthly cost that comes with it regardless how much gas is used.

Of course, you can't save what you don't spend ;) A very well insulated home can rely on only a heat pump.
Why is it so expensive to set up? Air conditioning seems to be everywhere in Asia and insulation is basically nonexistent
No clue. The last time i looked, the prices for a heat pump from known companies like LG or viesmann are similiar than a gas burner.

And with a heat pump you can even invest in PV and use that to be even more independent and later you can leverage an EV car either by never buying gas again or for storage.

Overall a very smart concept.

But perhaps he lives in a country were energy is very cheap, will stay cheap and is very stable?

I think the answer depends largely on the retrofitting cost, then less so on local market conditions. I.e. a niche market has fewer trained technicians and higher margins.

But the retrofitting issues can be substantial, particularly when it triggers updated building code enforcement. An older house with natural gas heating and no air-conditioning may need major electrical upgrades to support a heat pump system. Others may require ducts to be replaced. Or, other invasive work to meet newer insulation standards. Some houses might have some fluid-based radiant heating and require rework because it was designed for the higher fluid temperatures of a boiler while a heat pump system would use lower temperatures and higher flow rates.

Also, many homes may be subject to some kind of aesthetic rules which rule out the mini-split systems popular in Asia. The owner cannot just bolt new equipment or conduits to the exterior of the house. Instead, the above retrofitting tasks turn into major renovation jobs to tear apart interior walls.

Why do you doubt anyone has calculated the total cost of owning and operating such a system? I bought and paid for two heat pumps twelve years ago and the reduction in energy costs resulted in them paying for themselves after 11 years. The cost of ownership was simply the purchase and installation cost as I did not take out a loan or receive any government funding. There was virtually no maintenance required except cleaning the humidity drain half a dozen times. Right now I'm waiting to see how long they last before they fail so I can calculate the total amount of savings. I should also point out that because my heat pumps are 12 years old, they only have a CoP of 3, while new heat pumps have a CoP of 4 and it is expected units with a CoP of 5 will be available within a few years.
In germany this topic was disucssed and is still discussed up and down and a TON of studies and caclulations exists.
We recently replaced our old leaking big-ass-tank gas hotwater service with a continuous flow gas system.

I looked into heat pumps, but cost the of the device + installation + an electrician to run a new line (seemed that would be needed) ... I dont think it was ever going to break even over the rated life span of the system. The cheap ones were still 3 times the price of a gas system, just for the hardware. That and I would have to buy the heatpump from out of town, so getting any warranty/servicing might be more drama. And I really didnt want to listen to a cheap compressor tick-on all the time.

Another sad mark in the "wish I didnt have to kill the planet but ..." column. Feels like a rich mans game.

> Another sad mark in the "wish I didnt have to kill the planet but ..." column.

The high cost of the hardware, installation and maintenance suggests that you would rather "kill the planet" with the system installed?

I'm not sure whether your question is some kind of flippant accusation, but in case you're being genuine: I think the poster you quoted is saying something like:

if I could afford to do the right thing for the planet, I would - but I cannot afford to and am forced to do something which I know is detrimental.

> kind of flippant accusation

No. I rather meant to indicate that it might have been a good decision. There are some studies here from Germany that suggest that heat pump systems can lead to higher total CO2 emissions than using alternative systems. (I think it was compared to an infrared heating system with solar installed.) A high price of the hardware itself and the associated costs of installing and maintaining such as system might be a good indicator of why that is (higher complexity).

Just because a solution appears "green", it doesn't necessarily have to keep its promises. Especially when people do panic installations as has happened here in Germany, they might get sold on an idea rather than a reality. Hardly a benefit for the planet.

> There are some studies here from Germany that suggest that heat pump systems can lead to higher total CO2 emissions than using alternative systems.

Were these studies, or "studies" that were effectively marketing for Russian supplied gas, which until two years ago was a state level foreign policy goal, complete subsidies that advantaged fossil fuel heating and local politicians getting kickbacks from "interested parties" on the side.

Similar to the sugar industries and their "studies" about fat.

> Were these studies, or "studies" that were effectively marketing for Russian supplied gas

I guess your next comment will be that the Fraunhofer Institut has been infiltrated by Russians?

https://www.ibp.fraunhofer.de/content/dam/ibp/ibp-neu/de/dok...

And here's a video with all the information on different studies, universities and companies involved. This is basically a guy helping german real estate companies to survive in the current environment. It's in German. Translate it for yourself:

https://www.youtube.com/watch?v=pRe_Fu28CQs

I do not read German, but the literature is from 2008-2016 which does coincide with the peak of natural gas hysteria. Money might seem neutral but a big part of oil money has gone to lobbying, as was recently highlighted by Saudi oil fund leaks.

With that said you need to say more, we have been using heat pumps for decades and it is a great thing. The Nordics has cheaper electricity though. My point is it all depends.

> big part of oil money has gone to lobbying

That may be true (as it probably is for most big industries), but what does it have to do with what I have been saying? I have been talking about a comparison between two electric systems. The Fraunhofer paper just provides evidence that the COP of air heat pumps is much worse than advertised on average. If you are talking about the parent comment that said that they installed a gas system after looking into the heat pump: even there it is not clear if a heat pump system is better in terms of total emissions. It heavily depends on what kind of home you are equipping, because you also have to account for emissions caused by upgrading and maintaining insulation and other facilities, and for emissions caused by conventional power plants to supply the electricity for the pump (and the flow heater for hot water). The german energy mix, for instance, does still depend heavily on conventional plants in winter, even if the wind is blowing: https://www.smard.de/home/marktdaten?marketDataAttributes=%7... and during summer your expensive heat pump will just sit idle.

> we have been using heat pumps for decades and it is a great thing.

Great for your finances, the environment or what exactly?

> My point is it all depends.

It does. So we better look into the details instead of making decisions based on who has been accused of lobbying most prominently. But most people are not interested in looking into the details. They just want to appear "good" based on what's currently being seen as "good". Marketing departments know that.

(comment deleted)
Great for the environment here since the nineties, but as you say you have to take capacity planning into account. That the german grid is so sold on carbohydrates is a problem and a bias in the debate over the last decades. I say this as a neighbor who does not read much german.

I think we are in agreement on the facts just discussing the issue from different viewpoints.

Thank you for your comments btw, they gave a good second perspective! From my experience doing everything you need for a heat pump to work is a great return on investment, and the carbon life cycle analysisis is beyond great. I think monetary costs are just taken for granted if you do not see burning fossil fuels as the only solution.
Thank you for yours as well. It's an interesting discussion.

As another commenter pointed out, it all depends on the electricity source regarding the carbon life cycle. I posted another comment with the best detailed analysis for my current environment I could come up with and it's clear to me that the result doesn't warrant a definitive positive outcome for the heat pump.

With a low CO2 emission electricity source, I would agree that a heat pump system can make a lot of sense if your goal is to reduce emissions.

> I think monetary costs are just taken for granted if you do not see burning fossil fuels as the only solution.

That sounds like a rich people's perspective. What if you don't have the money? If it's really about transitioning the heating of all homes away from carbon emitting sources, then this will only work if the solution is cheap, because not everyone is wealthy enough to afford the transition.

If you implement policies that force people to upgrade, as was done in Germany, you will only transfer even more wealth from poor people to rich people. And I would argue that this also reduces the overall wealth in the system substantially since energy is an input to any product or service. At some point that leads to serious social and political issues as can be seen in Germany right now. This puts the whole enterprise of transitioning at danger once people demand radical political change.

The first link doesn't say anything about co2 at all. It talks about some inefficiencies. This doesn't mean its a bad choice and there are not many alternatives anyway. Not everyone wants an infrared based heating system or a air basesd (which would also work with a heat pump, air to air).

The second link is an interview were there is already a counter video. Rieck does not verify all sources and interviews a broad spectrum of people.

https://www.youtube.com/watch?v=KZS9HzuQck8&ab_channel=Prof....

Also, just food for thought: If one unit of gas has one 1kWh energy, a heat pump can make 3-4kWh out of it (You are following right?).

And panic decisions: ITs very critical that you can consume energy and not just oil or gas because in 5-15 years, the co2 tax for gas and oil will be higher and you will still only be able to consume those.

The bad decision is to do nothing or to renew your oil/gas burner.

The good decision is heat pumps, infrared whatever you like and doesn't consume oil/gas or can be easily switched.

Btw. investing now in germany in PV and a heat pump (for owners of houses) is with a high chance the longterm cheaper solution overall.

>Also, just food for thought: If one unit of gas has one 1kWh energy, a heat pump can make 3-4kWh out of it (You are following right?).

The decision is a little more complicated than that. If your electricity comes from natural gas, then you have to account for inefficiency in production of electricity and losses during transmission.

On the other hand, furnaces are not 100% efficient either, the cheap ones are 80% and the 95% efficient ones are more expensive, which narrows the gap.

Modern heat pumps can easily maintain a high enough COP to match or beat a furnace, and if you live in an area that needs both heat and A/C at different parts of the year, a more efficient unit benefits you year-round as opposed to spending more on a furnace. And if your electricity isn't coming from fossil fuels... then it's a moot point to begin with. You can't run a furnace on wind.

(comment deleted)
> Also, just food for thought: If one unit of gas has one 1kWh energy, a heat pump can make 3-4kWh out of it (You are following right?).

Not really following. I think that's a central point of the discussion. Is that COP realistic? Even after re-watching the follow-up videos on that, I tend to say no.

If we assume an energy mix of 30/70 wind/conventional during winter and conventional means lignite, hard coal, nat. gas. Taking the numbers from Quaschning (https://www.volker-quaschning.de/datserv/CO2-spez/index_e.ph...) let's say we have CO2 (equivalent) emissions of 700g/kWh for electricity generation on average (where nat. gas mean is 436g) incl. the upstream chain. 700x0.7 = 490g/kWh (wind subtracted). Now that has to compete against 200g/kWh for nat. gas burned in the furnace, disregarding any losses in both cases. 490/200 = 2.45 which would be the COP needed to break even. And that is without production and installation emissions with regard to the whole heat pump system, including a potentially common replacement of radiators/floor heating, installing a flow heater for hot water and so on. Also disregarding that the flow heater will have a COP of 1. Please correct me if there's an error in my calculation. It's just a back of the envelope thing and won't be accurate, but hopefully good enough to illustrate my point a bit.

> the co2 tax for gas and oil will be higher and you will still only be able to consume those.

As discussed in the reaction videos, I think it's not a fair point to compare the current costs to hypothetical future costs. Especially not if the german official sources state that the gas price will not substantially rise until 2035. But that's a point of discussion that's based on so many ifs that it's not really one I'd like to have at this point. We are basically at a point in this country where the government has to revert its policy on Diesel tax increases on the farmers. It's unclear to me if tax increases on nat. gas will be accepted by the population.

> There are some studies here from Germany that suggest that heat pump systems can lead to higher total CO2 emissions than using alternative systems. (I think it was compared to an infrared heating system with solar installed.)

Is solar + infrared the most common form of heating in Germany apart from heat pumps? Otherwise it's a dishonest conclusion to say heat pumps can lead to higher CO2 emissions. It's possible that another system is even better. Anything driven entirely by solar probably has no operational emissions. But what if the heatpump is also driven by solar?

The honest way to compare is to compare these various alternatives to the most common form of heating, which is probably still gas.

This is a thing I've been wondering about for a while now. Energy and labor are the biggest factors that drive supply chain costs in just about every industry. The more you spend on something, the more energy and labor likely went into creating it. Energy production obviously emits carbon. Some methods more than others, but with how immensely complex the supply chains are for most products (a global market with materials and parts and labor sourced from thousands of places all over the globe) I suspect it usually just averages out for the most part. Similarly, labor is done by people, and people all have their own carbon footprint. Again, some more than others, but with a global supply chain it sort of averages out.

So if you're spending significantly more money overall on something in order to reduce your own carbon emissions, there's a pretty reasonable chance (barring any detailed analysis to prove otherwise) that the cascading effects of that spending are actually resulting in more carbon emissions in total than if you'd simply gone with the cheaper solution.

Obviously this can't be universally true. It's a bit of a hand wavy argument, and the reductio ad absurdum conclusion would be that reducing global carbon emissions is impossible (which obviously isn't true). But I still think its something worth considering before making individual purchasing decisions based on perceived "greenness" to the demerit of price.

(I'll also note that if hypothetically a carbon tax or carbon credits were instituted globally then this price-based way of estimating carbon emissions would suddenly become not just a rough approximation, but a highly accurate measurement.)

> So if you're spending significantly more money overall on something in order to reduce your own carbon emissions, there's a pretty reasonable chance (barring any detailed analysis to prove otherwise) that the cascading effects of that spending are actually resulting in more carbon emissions in total than if you'd simply gone with the cheaper solution.

Or you reduce your carbon and increase costs massively, but another country doesn't, and your industry dies while theirs flourishes.

In other words money is a reasonable approximation for energy and hence carbon emissions, at least at an individual level.
Yes thank you, that's a very succinct way of putting it.
> Obviously this can't be universally true. It's a bit of a hand wavy argument, and the reductio ad absurdum conclusion would be that reducing global carbon emissions is impossible (which obviously isn't true). But I still think its something worth considering before making individual purchasing decisions based on perceived "greenness" to the demerit of price.

I think the reductio ad absurdum conclusion here is the degrowth-sounding argument that we need less economic activity to reduce emissions.

One thing your analysis may be missing is what you're going to do with the money saved.

> Energy and labor are the biggest factors that drive supply chain costs in just about every industry.

Well, scale as well. Unit costs go down as production efficencies go up.

Instant on tank-less water heaters are a good step on energy efficiency and emissions reduction. There are a couple of tricks, it is best to be 'pilot-less' and the other is the gas line usually has to be larger, so it isn't always a drop in replacement. This is due to it having to heat the water quickly using a higher amount of gas while running.
I have a tankless propane system on a house with 2.5 baths. Works great, but it takes a few seconds for hot water to flow.
Aren't they also inappropriate for showers, as in they can't heat the water fast enough for a hot shower?

Feels like a poorly thought out panic solution here in the Netherlands, where they're saying they're going to shut off gas in n years (number keeps changing, because it's more of a scare tactic to get people moving).

> Aren't they also inappropriate for showers, as in they can't heat the water fast enough for a hot shower?

Yep. I have looked at some newly built homes in my area. All of those that have heat pumps have flow heaters installed for hot water. So you have a COP of 1 there.

Heat pumps for domestic hot water are basically always storage systems (I have a heat pump storage system and it's excellent). For heating radiators or underfloor it does work (and can be incredibly efficient) to do constant flow but it wouldn't work well to do for showers etc.
A good heat pump water heater will have an insulated storage tank and backup resistance heat. Ours has plenty of water for a long shower but if you drain it faster than it can pull heat out of the ambient environment, the resistive heat kicks in (you can disable this if wanted) and you’ll continuously get warm water. We generally only notice that with guests in the winter - in the summer, it’s basically free since we’d be using the main heat pump to cool the house anyway.
Are we reading the same article ? "The survey found that two-thirds of heat pump owners and 59% of gas boiler owners were satisfied even without extensive energy efficiency upgrades."
I don't doubt that heat pumps are cheaper than gas bottles for a moment, especially in Europe, but it sounds like they also added a bunch of insulation at the same time as installing the heat pump.

Anyway, newer heat pump systems are great. I'm low-key hoping the 13 year old gas furnace in my attic kicks the bucket so I can replace it with another of the same system we use to heat/cool the downstairs.

If it kicks the bucket in winter you'll be in a bad place. On top of it, our local laws (Swiss) forbid you replacing old tech, so you will have to go immediately through the hoops of quickly installing a heat pump of sorts (good luck with that).
I'm in the US, my downstairs gas package unit actually stopped working in November and we had a new system installed within a week of accepting the offer.
I thought this was a new kind of air-source heat pump without all the problems of existing ones, but no, it's just a heat pump. Inappropriate for many (possibly most) dwellings in the UK, and the government is bribing people to install them.

For what it's worth, I think systems like https://www.tepeo.com/the-zeb will eventually replace gas in the UK, not ASHPs.

Similar technology is being trialled at some army barracks: https://www.telegraph.co.uk/news/2023/12/30/military-trials-...

> Inappropriate for many (possibly most) dwellings in the UK

Why ? UK is well above freezing (and even them, heat pumps _work_ below freezing, even with a COP > 1). So I'm curious about your assumption

I expect it's more to do with how poorly insulated most UK homes are
Insulation and having outdoor space to put the thing without sacrificing half your garden.
The OP did a bad job but here are my guesses.

Most traditional UK homes do not have central air, they use boiler/radiator systems for the winter. Retrofitting these homes do have central air with a heat pump probably does not make sense.

I don't think the product the OP linked was a very good example either. It's just an electric boiler that somehow stores offpeak energy to be used during the day. Don't know a lot about boiler systems but I cannot imagine these are that revolutionary and there are other similar systems out there, it is just an electric boiler with a smart energy/battery storage system to capture the off peak energy...seems like you could do something similar with a standalone electric boiler and a battery backup system.

Heat pumps work perfectly fine with radiator systems.
They do indeed, same with heat pump style water heaters used in America.
Can you link a drop-in heat pump replacement for my Vaillant gas boiler mounted in tiny apartment bathroom, which heats the radiators in the winter but also provides hot water year-round?
Talk to your local gas/water/heating instalation company, they are the experts.
Yes. For example Daikin Altherma, but I'm sure that every brand has a compatible system
It seems like it requires an external unit. I cannot easily mount an external unit. The bathroom is far from external walls, boiler is connected to the shared air intake in the wall that leads to the roof. So this doesn't look like a drop-in replacement.
Outdoor units are pretty flexible in the sorts of places they can be mounted and the insulated refrigerant lines can be run to the interior of buildings fairly easily. Don't just assume a solution can't work until an expert says no.

And even if you can't hook into your existing radiators wall mounted mini splits don't require extensive interior changes to function (plus you get cooling as well)

I do have a mini-split AC which can also provide heat. It is OK for autumn and spring but it is a no match for a radiator heating when it's really cold outside in the winter. Yes, of course I can run the lines through the whole apartment but this is a much costlier proposition.
Thermal storage bricks are a lot cheaper than batteries and chargers. The bad part is that it's resistance heating, which throws away a lot of exergy.
Agreed! I just said battery to cover any type of energy storage mechanism.
No, that isn't accurate. Air to water heat pump systems can be incredibly efficient and effective, even if the insulation isn't great. Flow temperatures are usually lower than gas boilers, so sometimes radiators need to be upgraded to larger ones but with a good quality heat pump and proper setup (weather compensation being a big one) there actually are few problems.

There is a huge education gap unfortunately, since there are grants to install them so you get dodgy installers doing crap jobs. Even with a high quality heat pump, if it's not set up correctly you can get COPs as low as 2.5 or so and pay more than having gas. There are some good channels on YouTube of people with the proper training making fairly minor changes to these systems and acheiving SCOPs around 4 which is cheaper than gas.

I think you are replying to the wrong thread? I never argued that they would never work, I am a big proponent of heat pumps. Just taking a stab at why the OP thinks they are not good for UK. Retrofitting older UK homes probably takes more steps than what the government grants are providing.

Thanks for the information though.

My understanding (and I'd love to be wrong here because it annoys me that I can't take advantage of high efficiency systems) is that:

1. Existing UK homes use radiators that would need to be replaced with larger radiators with an air-to-water heat pump, due to the water not being as hot as a traditional radiator system. Some of this is cost (replacing radiators), some of this is simply not having the space - many radiators are installed below windows so there isn't much scope to increase their size

2. Replacing radiators with an air-to-air system in each room is too expensive (especially since older homes often use solid brick/concrete for internal walls), as well as a large number of terraced houses with limited space for external piping/units.

3. Our mild climate (as well as housing stock age -- and, I'm betting, good historical access to local fossil fuels) means UK homes are very poorly insulated, and with our humid climate can have humidity + mould issues if retrofitted with insulation that reduces drafts.

The radiator upsizing makes sense, but there also exists high temperature heat pumps (~70C) that work with "old" radiators
Yes. The other issue in terms of housing stock is that a lot of the more recent housing stock has nowhere to put a cylinder for hot water, which means it's not practical to use HPs for hot water for showers etc. This either means replacing showers with instantaneous resistive heating-based "power" showers or keeping two systems even if you can retrofit with an air to air HP for space heating - adding cost and reducing savings available.

But the biggest barrier is the relative cost of gas vs electricity in the UK. Gas is about 4x cheaper than electricity per kWh so even with a COP of 4 the efficiency savings will take a long time to pay back capital cost.

Most boilers sit in peoples homes. An ASHP sits outside and you will need at least 5sq meters of space with excellent ventilation. That excludes many people (including me).

But even then during winter the average ASHP makes too much noise. Planning regulations are starting to recognise the fact that they can be a nuisance in semi-rural areas, and your neighbours will hate you.

This ignores all the problems around having to retro-fit larger radiators in older homes due to lower flow temperatures.

I don't know what you folks are able to choose from, but my neighbors have one of those installed last year and I can't hear it. So my guess is that noise is an old story which keeps being told - unless old models is all one can get.
> you will need at least 5sq meters of space with excellent ventilation

I don't see where you read that, but at least for Daikin ones, the front must be clear, but usage can be shared (eg. a driveway)

The problem is at least partly because people in the UK are enamoured with old houses to the point of detriment when it comes to things like thermal efficiency. There are all sorts of heritage laws, local "conservation areas" etc that forbid things like double glazing, modern insulation, etc. The quality of the typical housing stock here is very poor.
An electric boiler is never going to deliver more energy then the energy you put in to it (in the form of electricity). A heath pump can because it extracts heath from the air (or better said the water in the air).

Now if this were in France with a modern grid and nuclear power it might stand a chance. But the UK with it's aging grid and aging power plants? I doubt it.

We need the "hybrid car" of boilers right now I think.

Jumping from gas to ASHP is too big a hurdle for most as it involves many changes (upgrades in electricity, insulation systems, radiator upgrades and/or redoing the floor with underfloor heating).

I think an immediate, gradual, cheaper solution would be boilers being run on biofuel.

Read the first line of the article, it specifically references an air source heat pump.
The-ZEB are very thin on the details, is there a technical description of how it works?
Purly heating by energy is the worst case scenario.

I have to believe your 'the zeb' system has to be a scam as the energy amount such a small device can store, doesn't add up at all.

If it requires a big water heating tank, than this device should be as big as a computer + a heating coil.

Whatever they do with there 'energy core' its either magic and patented or just a scam.

Heat pumps could actually lead to a net increase in energy usage in northern areas because they can double as air conditioners for cooling in the summer. Normally homes in northern areas don't have AC and you just have to get through the relative short period when its hot enough that it would be nice to have. But with heat pumps, you just switch to AC mode. Also, those periods of hot weather are getting hotter and longer in duration.
But demand is lower in the summer, so this shouldn't effect renewable energy requirements.
This is regionally specific. The US south, for instance, sees higher usage in summer due to air conditioning demand.
The whole premise for the original parent comment was talking about Northern regions. So yes, this whole thread is regionally specific.

Talking about the south is silly because in most of the southern US it is near unlivable with humidity to go without A/C.

That has little to nothing to do with heat pumps does it?
This is a good point, summer time could potentially use solar.
And with sensible planning like overcooling during day-time. It could actually utilize the production effectively. Too hot nights are still relatively rare.
> Also, those periods of hot weather are getting hotter and longer in duration.

This is why I’d characterize it as potentially earlier use of AC: we’re already seeing many people who didn’t previously need it buying ACs so the greater efficiency of most heat pumps is going to be welcome as that trend accelerates. I live in the mid-Atlantic region and our heat pump system lowered our annual electricity consumption even though we got rid of a gas heater because the savings over our old AC in the summer outweighed our increased winter demand (obviously the numbers in winter are worst for more extreme climates but recent years have really brought significant efficiency improvements vs. older AC designs).

The other thing to remember is that summer is the easiest problem: the times when you need it also tend to be when solar is producing well and that’s cheap and easy to deploy. Winter is much harder because its demand has less sunlight and often coincides with cloudy weather.

(comment deleted)
Thats a no brainer.

If the sun shines a lot, we will have a lot of energy we can consume through an AC.

Overall a heatpump will lead to a 2-4 times net energy reduction.

Your normal car can use 30-40% of the energy in gasoline. We could just make energy out of it, use the process energy and drive a heat pump and we will be above 1 kWh from 1 kWh of gasoline energy.

I (self installed) a heat pump and I love it.

Sure, it's not really efficient (COP ~1.5) when it's -10C outside, but this happens 1 day per year. Most of the time the COP is around 4: that means that it uses 1kWh of electricity to produce 4 units of heat. My electricity kWh is .17cts, so the final heat kWh is ~ 0.17/4 = 0.04cts, which is awesome.

Using france's electricity production mix, that means that I can heat my house for 60/4 g/kWh = 15gCO2/kWh.

It is a bit misleading. Insulation is the main cause of lower energy bills. Then, once your losses are at a minimum you just need a bit of a kick to keep the warmth.

Any system will do once your energy losses are miniscule, e.g. think of the passive homes.

I'd love to know more detail on the insulation as I live in a Victorian stone building. One person says "external walls internally insulated [...] and the loft insulation improved, a process she describes as “very invasive” but worthwhile." Presumably they're stripping off the internal lath-and-plaster from external walls then replacing with insulation-backed board. Maybe the the new room size is smaller meaning any plaster cornicing has to be ripped out/replaced. I can see why she calls it very invasive. Personally I find draughts to be a huge problem. When it's cold and windy it's especially cold inside. But I don't know how to fix draughts without risking dampness or rot - never found any government guidance on this. It's a huge pain and I am not sure there is an easy "insulate" solution for these old properties.
You can probably buy "draft sticks" or something similar. They put out a little bit of smoke that you can use to find the source of your worst drafts so you can get them sealed.
I'm a fan of heat pumps, but as a Canadian living in the UK I think the _first_ steps should be things like finding and patching up drafts, using double-glazed windows with low-e coatings, and improving insulation.

Those will let you get the most out of an efficient heat pump.

Don't forget heat recovery ventilation.

The house I bought used originally a wood furnace which created a good draft of fresh air from the walls by sucking the ambient air into the chimney. Once the furnace had been replaced by an electric system (first radiator then heat pump), the air became stale in the house, causing all sorts of incomfort and humidity issues.

It's insane that buildings on the historic register are not permitted to install modern, efficient windows as mentioned in the article. Replicating the look 90%+ should be pretty easy, so why on earth would owners be banned from improving the efficiency of their home in a nearly transparent way.

Insulation and air sealing should be heavily subsidized. Regardless of the energy source, using less energy in the first place has a compounding carbon benefit for the lifespan of the building (which is almost certainly multiples of the lifespan of the current heat source).

I was seriously in the market for a heat pump system for the upper floor of my home. The current oil fired furnace system works but oil is expensive and the heat from our pellet stove doesn't reach up to the second level very well.

Then I started working at a co-working space that has a heat pump system and the HVAC techs are in here working on it a couple times a year as we wear parkas and hats because it's 10C in the building. Or it's summer time and I'm trying not to sweat on my keyboard.

This led me to look more closely into reliability and longevity of these systems and the math just didn't add up, even with very optimistic values for MTBF and expected lifetime.

So you have had the experience of one space using a heat pump but you don't have more information regarding it?

What type it was? How well insolated was the space? Did the manager keep the temperature low on purpose? What does the summer time and sweating to do with the heat pump?

Is your house insulated?

I did say I looked more closely at the details of such systems and the suitability of my house, insulation level, climate was part of of that. The singular experience was just the trigger to look into it and I determined that they aren't as great as the marketing makes them out to be. At least the models available in my area.
I was just listening to an NPR story about heat pumps, they act like a refrigerator in reverse.
Live in rural England and have a heat pump with 7kW of solar PV and 16kWh of battery.

Any outdoor temperature around 10 degrees the, heat pump keeps the house at 20C using about 1kW of power and is only drawing power for half the day. Warmer than 10C, the amount of power it uses is negligible. However, today it’s -1C and the heat pump is drawing nearly 3kW all day to keep the house at 20C. Imported 40kWh from the grid today mostly for heating. Price per kWh is about 27p. Not cheap.

It all balances out when the days get longer and sunnier. Can generate 50+ kWh of electricity, which more than covers our usage so we export a fair bit.

I set the heat pump to heat water to 55C between 2am to 5am and again between 2pm and 4pm if necessary. We also divert any excess electricity after usage and charging batteries to heating the water tank via immersion heater. Had 4 family member over for Christmas and we didn’t run out of hot water once!

Pretty happy with it overall.

Can you add more solar?
Can probably add a few more kW of solar PV but I'm not sure there's much point unfortunately. What I've realised is that the limiting factor is really the rubbish UK weather. Over the last 4 weeks the most I've generated in a day is 5kWh. I guess that will change in a month or two though when the days get longer and hopefully sunnier.
In New Zealand, heat-pumps are the most common form of heating. Works great, far more cost effective than other forms of electrical heating.

We've never really done boilers, previously it was mainly wood fires for heating. Coal used to be widely used, but we've banned burning coal in most residential areas, and woodburners in a lot of residential areas are subject to stringent regulation to improve air quality, we used to have phenomenal smog issues in winter due to temperature inversions and woodfires.

My house still has two log-burners, but with our two heat-pumps and decent double glazing, we didn't need to light the fires last year.

And the real bonus is that they can run in reverse and cool your house, which is amazing in the hot dry summers we get in my area.