Air-source heat pumps - are they good/crap?

[r3g]

OutInTheShed said:

The problem is, a lot of people don't want to leave the era of cheap gas.

Like it or not, the UK is on a pathway to 'decarbonised' home heating.
https://www.gov.uk/government/publications/heat-pu...

Between 2025 and 2028

Requirement that all new domestic-scale hydronic heat pumps are ‘smart’ comes into effect
Fossil fuel heating in homes and businesses off the gas grid to be phased out

Between 2028 and 2035

Reach 600k heat pump installations each year
Achieve a fully decarbonised electricity system, subject to security of supply
Aim to phase out fossil fuel heating in homes and businesses on gas grid

A lot of people are starting to wake up to the possibility that their million pound houses will be unaffordable to heat.
There's not going to be much 'live and let live' from Government.
2035 is not that far away.

Hence my earlier comments saying to buy (or better, stockpile!) gas boilers before they ban them! It's clear what direction we're heading and the government are quite happy to see us all freeze to death under the fake climate BS scam.

[Tom8]

Gas will be cheap again next year following deal with US. Broker forecasts look very favourable.

[Evanivitch]

r3g said:

Hence my earlier comments saying to buy (or better, stockpile!) gas boilers before they ban them! It's clear what direction we're heading and the government are quite happy to see us all freeze to death under the fake climate BS scam.

Are you going to start stockpiling bottled gas too?

[Jambo85]

RE Norway - despite the fact that they produce copious amount of hydrocarbons, they had vast hydro reserves prior to this, so already had cheap and clean electricity, and therefore don't really have a domestic gas network on the same scale we have. And as a country they make an absolute fortune by exporting most of their gas to us and ze Germans.

Basic resistive electric heating was common in Norway, and apart from the capital cost there is no debate that heat pumps are an improvement on that. Comparison to gas isn't really a debate for them.

[borcy]

OutInTheShed said:

The problem is, a lot of people don't want to leave the era of cheap gas.

Like it or not, the UK is on a pathway to 'decarbonised' home heating.
https://www.gov.uk/government/publications/heat-pu...

Between 2025 and 2028

Requirement that all new domestic-scale hydronic heat pumps are ‘smart’ comes into effect
Fossil fuel heating in homes and businesses off the gas grid to be phased out

Between 2028 and 2035

Reach 600k heat pump installations each year
Achieve a fully decarbonised electricity system, subject to security of supply
Aim to phase out fossil fuel heating in homes and businesses on gas grid

A lot of people are starting to wake up to the possibility that their million pound houses will be unaffordable to heat.
There's not going to be much 'live and let live' from Government.
2035 is not that far away.

That's the plan, whether that happens is another matter. Roll out of new technologies often takes far longer than a gov's website suggests.

[JuanCarlosFandango]

Jambo85 said:

Basic resistive electric heating was common in Norway, and apart from the capital cost there is no debate that heat pumps are an improvement on that. Comparison to gas isn't really a debate for them.

Even the comparison with traditional electric heating isn't that straightforward. I've stuck mainly with them because:

Virtually no up front investment. £20-30 each, and installation costs are zero. You just plonk it in the room you need it.

They are ultimately flexible. You turn it on when you need heat and off when you don't. They start putting out heat in seconds when you switch on and stop when you switch them off.

Heat pumps might be 3 times as efficient (usually "up to") but if they have to be on pretty much 24 hours a day through winter that becomes less impressive. I certainly don't have all my heaters on for 8 hours a day all winter.

Also if your heating needs are relatively low (as they are in well insulated houses) then the savings aren't that great. If my calculations are right last month's electricity bill will be about £250, my biggest ever. If half of that is heating and I could cut 2/3 off that with a heat pump and do that 6 months of the year (all of which are insanely generous assumptions) I could save about £500 a year, so a cheap installation at £8,000 is a 16 year pay off, all things being equal.

If I further beefed up my insulation the heat pump might make more sense, but the actual savings would be even slimmer.

[Evanivitch]

JuanCarlosFandango said:

Heat pumps might be 3 times as efficient (usually "up to") but if they have to be on pretty much 24 hours a day through winter that becomes less impressive. I certainly don't have all my heaters on for 8 hours a day all winter.

That shows your lack of understanding. Firstly HP in any decent installation are above COP 3 in most conditions. Secondly, the heat pump isn't on all the time, it's available to heat all the time. It's like the difference between an electric oil heater and a radiant heater.

[r3g]

Evanivitch said:

r3g said:

Hence my earlier comments saying to buy (or better, stockpile!) gas boilers before they ban them! It's clear what direction we're heading and the government are quite happy to see us all freeze to death under the fake climate BS scam.

Are you going to start stockpiling bottled gas too?

I don't think there's anything to worry about (yet!) on that front as many industries rely on it so I think it will keep flowing through the pipes for considerable time. But as we saw a couple of years ago in Germany, gas became unobtanium (price wise) for a while, leading people to return to collecting wood to burn for heat. Unless someone manages to put a big wrench in the globalists' wheel of trying to set us back to the dark ages under the guise of "climate change" and needing to "save the planet" then that's where we'll end up, so maybe stockpiling wood burners and wood (and solar panels and large lithium batts) is not such a silly idea .

[Evanivitch]

r3g said:

I don't think there's anything to worry about (yet!) on that front as many industries rely on it so I think it will keep flowing through the pipes for considerable time. But as we saw a couple of years ago in Germany, gas became unobtanium (price wise) for a while, leading people to return to collecting wood to burn for heat. Unless someone manages to put a big wrench in the globalists' wheel of trying to set us back to the dark ages under the guise of "climate change" and needing to "save the planet" then that's where we'll end up, so maybe stockpiling wood burners and wood (and solar panels and large lithium batts) is not such a silly idea .

The industrial gas network will remain for some time. But local distinction networks to domestic will disappear much sooner if there's only limited customers on a street.

[OutInTheShed]

Equus said:

Norway has had dramatically better levels of fabric insulation than the UK for a very long time, too, of course, but has bugger all gas infrastructure in comparison - they didn't really start installing a distribution network until the North Sea Oil/Gas boom of the 1970's.

Conversely, the UK has had an extensive gas network and infrastructure for a very long time (back to the Victorian era, when we used it for lighting more than heating), but because of our early industrial revolution, we have had access to cheap fossil fuels for the last 250 years and so have not had the imperative to build energy-efficient housing until very recently.

This is one of the reasons I get frustratred with Caziques (from New Zealand) turning up with monotonous regularity on these threads to tell us we're all doing it wrong in the UK, whilst completely ignoring the fact that (in addition to different climate and different housing stock) our economics are very different. Google tells me that gas in NZ is much more expensive, relatively speaking: typically 60% of the price of electricity, per kWh, compared to being just 25% its cost in the UK.

I don't think that anyone has suggested that heat pumps can't possibly work in any homes in the UK ever at all, but they will always be less flexible than a boiler - that's a simple fact of the technology - and with our gas prices at current (and historic) levels*, they're never going to show a big advantage in running costs, versus mains gas.

If you don't have access to mains gas, the economic case for them becomes somewhat better, and if you only have access to electric as an energy source, they become a no brainer (provided you can contrive a cost-effective installation).


Is there a case for adopting heat pumps in order to help save the planet or (and I suspect that this is our politicians' real incentive) reduce reliance on energy from dodgy and unstable countries?

Possibly... but in which case the Government needs to dramatically shift the cost balance. Unfortunately, since they can't deliver massive reductions in electricity costs, this would mean imposing a massive tax hike on gas, which would be political suicide. This leaves them only with the option of using a relatively cheap campaign of incentives to dupe the gullible into making the change, regardless.

Edited by Equus on Tuesday 6th February 11:00

I'm not sure it will be political suicide to raise gas prices.

Gas prices may rise anyway if the cost of carbon capture is passed on to consumers.
Once consumers start switching to heatpumps en masse, the gas consumer is left paying for a bigger fraction of the network costs.

I think the heat pump hardware is expensive for what it is. If prices can be brought down as volumes ramp up, things may change quite quickly.

[Equus]

OutInTheShed said:

I'm not sure it will be political suicide to raise gas prices.

Then I suggest you don't seek a career in politics: the current shower are hardly likely to be re-elected in any case, but a tax to give a 100% increase in domestic gas prices, overnight (which is what it would take to properly incentivise a mass change to heat pumps) would probably cause rioting in the streets.

OutInTheShed said:

Once consumers start switching to heatpumps en masse...

Ah, so all we need do is keep an eye out for the flying pigs, then?

[gangzoom]

neth27 said:

The heat pumps in Norway are air conditioning units.
From that link
Heat pumps work on the exact same principle as refrigerators and air conditioning systems. In fact, the exact same heat pumps used to warm up houses in Norway are marketed as air conditioners in warm countries

Edited by neth27 on Tuesday 6th February 10:08

How do you use an ASHP to cool in summer? I was told it was not possible, hence we are getting AC units and sticking with gas. If ASHPs can function as both heating and cooling, we might have actually considered installing them.

[JuanCarlosFandango]

Evanivitch said:

That shows your lack of understanding. Firstly HP in any decent installation are above COP 3 in most conditions. Secondly, the heat pump isn't on all the time, it's available to heat all the time. It's like the difference between an electric oil heater and a radiant heater.

I'm pretty sure that's what the salesman was quoting and a quick Google points to the same, but I'm not claiming to be an authority. What is a more realistic COP?

[loudlashadjuster]

gangzoom said:

neth27 said:

The heat pumps in Norway are air conditioning units.
From that link
Heat pumps work on the exact same principle as refrigerators and air conditioning systems. In fact, the exact same heat pumps used to warm up houses in Norway are marketed as air conditioners in warm countries

Edited by neth27 on Tuesday 6th February 10:08

How do you use an ASHP to cool in summer? I was told it was not possible, hence we are getting AC units and sticking with gas. If ASHPs can function as both heating and cooling, we might have actually considered installing them.

It needs to be a) designed to do it, b) configured to do so (additional sensors, pipework), and c) legal to run them like that.

Mine is capable of it, but due to building regs it's not allowed to be used 'in reverse' in the same way I wasn't allowed to install a split a/c unit when I built the place.

[Jambo85]

gangzoom said:

How do you use an ASHP to cool in summer? I was told it was not possible, hence we are getting AC units and sticking with gas. If ASHPs can function as both heating and cooling, we might have actually considered installing them.

An AC unit IS an ASHP. But it's an air to air one, rather than an air to water one, which is what people probably most often mean when talking about ASHP in this country. Cooling a house by blowing cold air into it works, cooling by chilling the floor/radiators ... not so much!

[Jambo85]

OutInTheShed said:

Gas prices may rise anyway if the cost of carbon capture is passed on to consumers.

Under our current system, our electricity prices (a chunk of which still comes from burning gas) would show a similar increase in that scenario.

[Equus]

loudlashadjuster said:

gangzoom said:

neth27 said:

The heat pumps in Norway are air conditioning units.
From that link
Heat pumps work on the exact same principle as refrigerators and air conditioning systems. In fact, the exact same heat pumps used to warm up houses in Norway are marketed as air conditioners in warm countries

Edited by neth27 on Tuesday 6th February 10:08

How do you use an ASHP to cool in summer? I was told it was not possible, hence we are getting AC units and sticking with gas. If ASHPs can function as both heating and cooling, we might have actually considered installing them.

It needs to be a) designed to do it, b) configured to do so (additional sensors, pipework), and c) legal to run them like that.

Mine is capable of it, but due to building regs it's not allowed to be used 'in reverse' in the same way I wasn't allowed to install a split a/c unit when I built the place.

In addition to the above: it's technically quite easy to do with an air-air heat pump. With air-water you can theoretically use it to cool the water, so that you have 'underfloor cooling' (or the radiators become heat sinks), but you have to be very careful not to cause surface condensation, so in practice it's not really adviseable to attempt it (particularly in the UK, which is very humid, even in summer).

[Evanivitch]

gangzoom said:

How do you use an ASHP to cool in summer? I was told it was not possible, hence we are getting AC units and sticking with gas. If ASHPs can function as both heating and cooling, we might have actually considered installing them.

An Air to Air heat pump is an air conditioning unit.

A wet central heating system with radiators or underfloor heating would need carefully monitored due temperatures, but for the most part you're just asking for condensation!

[loudlashadjuster]

Jambo85 said:

gangzoom said:

How do you use an ASHP to cool in summer? I was told it was not possible, hence we are getting AC units and sticking with gas. If ASHPs can function as both heating and cooling, we might have actually considered installing them.

An AC unit IS an ASHP. But it's an air to air one, rather than an air to water one, which is what people probably most often mean when talking about ASHP in this country. Cooling a house by blowing cold air into it works, cooling by chilling the floor/radiators ... not so much!

A friend has a house built a few years before mine, and his is configured to heat/cool. It works very effectively, in fact.

As with ufh heating, the cooling is subtle (don't want condensation, after all!) but the floors are all cool to the touch in summer and it makes a big difference when the outside temps have been above 25C for a week or so as you don't get any heat build-up.

[Jambo85]

JuanCarlosFandango said:

Jambo85 said:

Basic resistive electric heating was common in Norway, and apart from the capital cost there is no debate that heat pumps are an improvement on that. Comparison to gas isn't really a debate for them.

Even the comparison with traditional electric heating isn't that straightforward. I've stuck mainly with them because:

Virtually no up front investment. £20-30 each, and installation costs are zero. You just plonk it in the room you need it.

They are ultimately flexible. You turn it on when you need heat and off when you don't. They start putting out heat in seconds when you switch on and stop when you switch them off.

Heat pumps might be 3 times as efficient (usually "up to") but if they have to be on pretty much 24 hours a day through winter that becomes less impressive. I certainly don't have all my heaters on for 8 hours a day all winter.

Also if your heating needs are relatively low (as they are in well insulated houses) then the savings aren't that great. If my calculations are right last month's electricity bill will be about £250, my biggest ever. If half of that is heating and I could cut 2/3 off that with a heat pump and do that 6 months of the year (all of which are insanely generous assumptions) I could save about £500 a year, so a cheap installation at £8,000 is a 16 year pay off, all things being equal.

If I further beefed up my insulation the heat pump might make more sense, but the actual savings would be even slimmer.

I acknowledged the up front cost in my post, no argument there. I don't agree that your assumptions are all insanely generous - heating will be far more than half of your electricity use in January, unless you're cooking loads, in the shower all the time and have your house at 10 degC.

Possibly we'll start to see some of this reflected in house valuations if energy prices continue to rise and somehow the electricity and gas prices become decoupled, and there's also no doubt in my mind that a well installed central heating system (ASHP or otherwise) is going to make a house more desirable than resistive heaters of whatever type, before you even consider running costs.