Are Heat Pumps Cheaper To Run Than Conventional Gas Boilers?
By Paul Homewood
The Mail has a useful supplement about alternatives to gas heating, which is relevant following the government’s decision to ban gas boilers in new build houses from 2025:
Wonderfuel gas, crooned the 1980s British Gas advert. How times change. As we approach the 2020s, British households are now facing Government efforts to shift them off the ‘wonderfuel’ and on to something greener.
In a significant announcement on Wednesday, Chancellor Philip Hammond said he wants to stop the installation of gas boilers for water and central heating in new homes from 2025 to reduce greenhouse gases and carbon emissions.
Although Hammond said nothing about existing homes, he hinted at more proposals that could spell the beginning of the end for gas central heating.
Some councils, such as Islington in London, are already developing centralised systems where many properties are sent heat rather than gas via highly insulated pipes.
But most people will have to replace their existing boiler with a new ‘green’ design if they are to give up gas.
What is unclear is whether any of the alternatives – such as heat pumps and biomass stoves – can rival the claim made in the old advert that gas comes ‘at a price that can’t be beat’.
Although many eco-friendly fuels promise lower annual energy bills, the financial savings can vanish through the cost of installation and maintenance. And whilst there are incentives in terms of subsidies, perversely these are being reduced – just as the Government wants us all to do more to save the planet.
The Mail on Sunday assesses the alternatives you can turn to:
Option 1: DIG DEEP FOR THE HEAT
The earth outside your home may not seem warm, but it can replace your gas boiler as a source of energy to heat your home.
To harness the heat in the earth, you need a so-called ground source heat pump.
This means digging 4ft deep trenches and laying pipes containing fluid. The scale of the pipe network will depend on the size of your home and garden.
The fluid in the pipes is warmed by the underground soil, where temperatures are generally from 6 to 12 degrees Centigrade throughout the year – even when the air temperature is below zero.
Heat pumps: The scale of the pipe network will depend on the size of your home and garden
This fluid flows into a heat pump, which uses clever technology to heat water for the home. Crucially, the device squeezes the energy out of a very large amount of tepid liquid and uses it to heat up a much smaller amount of water.
It does this by a process called compression. Hot water is then fed to a tank and around the home’s pipes and radiators.
Installing a ground source heat pump involves major excavation work and is an expensive project, costing from £10,000 to £20,000. Homeowners may save £300 a year on heating bills.
There is also a renewable heat incentive grant worth on average £2,500 a year over the first seven years. The amount is calculated based on how much energy is produced. There is no guarantee the scheme will not be shut or scaled back.
Meredith Annex, of energy research company BloombergNEF, says a ground source heat pump is efficient but most homeowners would not be able to afford the installation.
She adds: ‘Such a pump also requires a lot of space so they are probably only suitable for people living in the countryside.
‘But people buying in a new development may benefit from the builder having installed it already.’
Option 2: DRAW ON THE AIR OUTSIDE
With air source heat pumps, any heat from the outside air is taken in through a special fan on the side of the house. It works like a fridge in reverse. While a fridge disperses heat from a system of pipes at the back to cool itself, an air source heat pump absorbs the heat from outside the home to warm it.
It is possible to get heat energy from the air even if temperatures are as low as minus 15C. Using similar techniques to a ground source heat pump, if enough of this energy can be harnessed, it can be used to heat water for the home.
Warmth from vast amounts of air is absorbed at low temperature into a fluid. This is passed through a compressor powered by electricity, and the resulting heat is transferred to the hot water system in the house.
The fan resembles an air conditioning unit – and takes a day to install. But you also require special radiators or underground heating pipes that can bring the total bill to about £8,000. It works best in well insulated homes. Homeowners should save £200 a year in heating bills.
You may also be eligible for a renewable heat incentive grant worth about £1,200 a year for the first seven years. Again, this is based on energy usage and should not be relied on as a failsafe way to get your cash back.
Use the Department for Business, Energy and Industrial Strategy’s online calculator to work out your possible grant. Go to www.gov.uk/renewable-heat-incentive-calculator.
The article also looks at water source heat pumps, solar panels and biomass boilers, but these have limited applications. As indeed does ground source heat pumps, which really need a lot of space, something not commonly found on new housing estates these days. GSHPs are also, of course, extremely expensive to install.
So, let’s look closely at air heat pumps, or ASHPs. The chart suggests energy cost savings of £200 a year, but it is not clear what this includes.
But Greenmatch, an online provider of green energy solutions, give some detailed costings here. They reckon the installation cost could be between £7000 and £11000. On top of this, more money would have to be spent on underfloor heating systems if the benefits were to be maximised.
However, when it comes to running costs, their numbers don’t stack up:
https://www.greenmatch.co.uk/blog/2014/08/the-running-costs-of-heat-pumps#running-cost-factors
They say that the cost of running a conventional gas boiler would be £1005 a year. But this is nonsense.
Their own figures of 11000 + 4000 KWh, and 85% efficiency mean consumption of 17647 KWh. Gas is currently priced at about 2.5p /KWh, giving an annual cost of £441.
This tallies with my bills , as well as Greenmatch’s own chart:
They then list the running cost of the ASHP as £970 a year, more than double that of gas.
And this is before factoring in depreciation and interest on the installation cost.
As for the Mail’s claim of £200 savings annually, it may be that this is after counting the government subsidy via the Renewable Heat Incentive scheme (RHI). I have run the RHI calculator for our house, and the subsidy works out at £750 a year, payable for seven years.
It is certainly misleading for the Mail to claim that “heating bills are reduced by £200 a year”, if they have counted the subsidy.
In any event, there is no way the government can subsidise everybody’s new heat pumps, and the existing capped budget is close to being fully spent.
In practice, running costs for ASHPs are almost certainly going to be much higher than estimated by Greenmatch. As they point out, they are assuming houses are already well insulated. This is an important point.
A draughty house means that the heat pumps have to work much harder to maintain heating levels. This may sound obvious, but there is a definite amount of heat trapped under the ground or in the air, and the heat pump will have to work harder to extract heat if a great amount is needed, a fast supply is required or there is less heat than what is necessary.
In simple terms, you need to keep progressively putting in more energy to get out the same amount. [In technical terms, it has to do with the Coefficient of Performance (COP) which measures the efficiency of a heat pump and it does this by measuring the amount of power input compared to the amount of power output produced by the considered system. Hence, the higher the value, the more efficient the system is].
So either you have to pay more money out for proper insulation, or buy a bigger, more expensive heat pump, or accept that the system will struggle to supply the amount of heat you require.
The simple reality is that heat pumps, both ground and air source are not cheaper to run than a conventional gas boiler. On the contrary, without government subsidies they are considerably more expensive.
It is true that they are much cheaper to run than conventional electric heating systems, but that is another matter entirely.
Comments are closed.
NOT A LOT OF PEOPLE KNOW THAT 
Space heating can’t effectively & economically be time-shifted.
Therefore a significant proportion of the power domestic ASHPs & GSHPs draw from the grid will be at peak times 17:00 – 19:00 during December, January & February.
Precisely the hours the Smart Meter imposes the maximum tariff rate. That maximum time-of-use charge will only increase over time, as intermittents displace dispatchables in our generation mix.
Using ‘annual average’ electricity prices is disingenuous.
Not only Gummer is fraudulent, the whole caboodle, from heat pumps, via windmills and schoolchildrens’ “strikes” to EVs is crackpot, completely unnecessary and as unreliable as Al Gore’s Nobel Prize was unjustified and undeserved.
The UK’s proportionate contribution to global CO2 output, at 1.3%, justifies non participation.
Charles, shouldn’t that be ‘estimated global anthropogenic CO2 output’? When you factor in that man barely contributes 5% of the total annual output of carbon dioxide to the atmosphere, the remainder being of entirely natural origin, a 1.3% contribution to an estimated worldwide man made total of 5%, of a grand total of 0.04% of the atmospheric content of CO2, is about as significant as a fart in a spacesuit in global impact terms, if you would excuse my rather crude comparison? And we are expected to plunge ourselves in to penury to assuage the consciences of our virtual signalling political masters to make no impact whatsoever on the climate? Bonkers! If we were to nip back in time, say to the decade between 1930-40, when CO2 was at a level our masters would quite happily seek to emulate, what was the worldwide climate like? Bloody awful! Millions died across the planet in floods, cyclones, tornados, hurricanes, droughts, wild fires etc etc and that was the decade before even the deranged IPCC accept that mankind could have had any meaningful impact on the global climate. I suppose all those deadly events were just weather though, not climate change!
Thanks, Mack, for that illuminating, realistic, very meaningful re-analysis, which should be adopted by us all.
It will be overlooked however by the dishonest climate “Wolf, Wolf” criers but they should not get away with it.
Mack, very interesting. You say “5% CO2 man made”
I always work on a third of the 400 ppm CO2 from ‘man’- but I cannot remember how I got to this figure.
Where do you get your 5% from, because if it is correct then our green policies are even more suicidal than I thought?
What a total surprise! My ghast has seldom been so flabbered! When will the lunatics go back to their cells and allow real people to run the country!
So what happens if you get a leak in all this underground pipe work due to eg tree roots damaged / substandard / faulty piping over time ?
Its expensive digging holes and tearing up nicely laid out gardens etc etc even if you can gain access with plant after the housing has been completed.
So youve got a street of houses all pulling heat out of the ground in close proximity 24/7
Isnt that going to drag down the ground temp making the system work even harder ?
I would not believe any figures put out by the Government or any Green energy supplier. They will be nothing short of lies. In any event I thought the National Grid has already said they cannot handle additional demand with gas heating being changed to electric. They are going to be struggling to handle millions of EV’s.
Having said all that, where is the power going to come from with the closure of coal power stations and virtually no new gas stations being built.
Oh I forgot just like Labour’s money tree, the Tory’s have an energy tree.. .
I have a new, very efficient gas boiler and my bill is just about £1100-00 a year in its first year.
I estimate a ground source air conn wilk use maybe £200-00 more.
My gas bill is around £500, which includes cooking and hot water
Remember, you can use an air source heat pump for both heating and cooling. A few years ago now, I lived in a new 17 storey building in Canada where each condo had been fitted with its own ASHP. I have no idea how much each ASHP cost but it did not have to supply hot water, that was centrally provided in the building. Note that in Canada electricity is usually referred to as the “hydro” as most comes from abundant hydroelectric sources and is cheap.
Such is the climate in Canada there are very stringent heat insulation requirements on new buildings. Our only direct outside interface was the windows as we had other condos above and below us, and to each side. The common areas inside the building were separately cooled and heated but I don’t know how.
We lived on the south side of the building and with the solar gain of the triple-insulated windows we found very little heating was required, even in winter (-35C outside). Our ASHP was used mainly for cooling purposes in the summer (+35C outside) and was an ideal solution for our condo.
However, those who lived on the north side of the building found their ASHP provided insufficient heating during the winter and their condos didn’t need cooling at all, even in the summer.
So don’t expect there to be a one-size-fits-all ASHP solution for heating and cooling, even for new-build homes, it needs to be custom designed and that costs money to do properly, leaving aide running costs.
Heat pumps would work fairly well in England as they produce Ac well as heat. They are less efficient as the temperature difference gets bigger. Unfortunately they need back up thermal heating for really cold days. So a cold windless snap would wreak havoc. These are frequent during Englands winter. An alternative technology to reduce emissions would be to generate electricity with a fas engine and use the waste heat for heating. This would fit well with existing hydronic heating used by gas boilers. Such engines have been used in Germany for years.
It’s the total installation and lifetime running costs that matter.
Given that you can buy 2kw heaters for £20, with this most primitive electric heating, the only real cost is the cost of the electricity and no maintenance. It’s also far more healthy to live in a warm house with plenty of ventilation.
I suspect it would take an awful long time before you had spent as much on electricity for that solution, as you would on insulation, heating pipes/radiators and heat pumps, and their electricity and maintenance costs. AND after all that you will probably need a ventilation system with expensive heat recovery fittings. AND you will now need to be running something all year long – currently the heating goes off in spring and aircon isn’t really required (in UK houses) for comfort – it will be with all that super insulation.
Even with the probably optimistic figures given in the article, e.g. solar pv = 20 years to break even – by which time they will need replacing!
As far as saving money or saving the planet, none of this passes the sniff test.
And the number of times you hear that ashp and gshp systems just don’t work properly (always blamed on incorrect specification/installation) it’s just too much of a risk for such a massive expense.
So with the electric heat/cooling and your electric cars, how warm will the average house get before the electric grid goes “poof”?
a friend was unimpressed with his ASHP as, while the air blowing out was 20C, it was moving and thus felt cold…
The have variable speed fans , the air blowing out will be much hotter if you are below 20C as you near the temperature set point the fan speed slows and the air will be at 20C but at lowest speed will be barely noticeable ( placement of indoor unit is crucial). The main criteria at the temp set point is quietness from fan .
What you have described can happen when auto setting chosen, rather than ‘heat’ option, and the unit chooses to start with ‘dehumidify’ process , which requires a cooling cycle. Thus the cold air at 20C. I only use dehumidify for summer as a better choice than cooling, as its often the extra moisture in the air that makes it feel hot and clammy, its also a lower power consumption.
The attraction of heat pumps to politicians and public servants is the believe that they deliver “something for nothing” i.e. they deliver more heating than an equivalent amount of electricity. The COP (Coefficient Of Performance) referred to. The enthusiasm (theoretical only) comes from the Greenies.
But the COP drops drastically as the temperature difference increases. The ground source heat supply will prove a mirage. You will want heat in winter so the temperature of the soil will drop. Possibly that heat will be replaced in summer, but you need a long warm time for the heat to penetrate the soil. Using water from a nearby lake would be more effective, especially as the ice layer would insulate the water body, so you would be getting a heat source at a minimum of 1℃. To heat your house to, say, 25℃ you would need lots of water whatever the COP. This is why house owners in northern USA find that lake sourced heat is superior to a ground sourced supply in winter.
An even better scheme is for the heat extraction pipes to run through a gas fired box, but why not use the gas directly?
The other problem is that heat pumps require a stable supply of electricity. A wood or coal fired heater looks a much better solution, particularly if you can take the occasional governmental idiot and throw them onto the fire.
A colder outside temperature just mean you install a larger rated unit . For ASHP moderate cold outdoors may be 5-6kW rated , if colder area you may need up to 9kW output – which I think is near to the largest size you can run on a home single phase 240V supply. That may vary according to different countries standards.
Once the house warms up , the heat required drops which is just as well as the night gets colder the later it is. Set the unit to start at a time late afternoon /early evening that produces warmth you need. Some now can be started via smart phone internet connection.
I investigated ground source heating some years ago when we had a house with a stream running through the garden which came from a spring and never fell below 5 DegC even in cold weather – I would not have needed much pipng embedded in the water. However I could not make the sums add up, the payback period was in excess of 10 yrs, and that assumed no major repairs were required in that time. The Coefficient of Performance falls as the differential temperature between the cold and hot sides increases, thus requiring more electricity to drive the compressor when you need most heat.
So my conclusions are
a) anybody buying a house with one of these systems will soon install a conventional boiler. If there is no mains gas they will have to revert to LPG or oil
b) the UK will never have enough spare electricity generation capacity to run these units given the closing of all the coal fired stations with no replacements in the pipeline, and the projected rise in EV which will also require significant extra MW of genratin cpapcity.
In reality I suspect neither this mad decision along with the equally mad decision that there will be no more internal combustion vehicles after 2040 (?) will never actually come to fruition – it iwll end up ion the too hard department jsut like Brexit has !
as a previous comment says – UK contributes about 1.5% of world CO2 output so even if the UK shut down completely tomorrow it would have no effect whatsoever. since there are no engieers in the House of Commons then none of them are capable of understanding the calculations !
Engineer John
Already air source heat pumps are proving a problem. They are noisy and can be very tiresome for neighbours. Ground source heat pumps are known for becoming much less effective towards the end of winter as the ground cools. A relative of mine in northern France has a ground source system and as well as eye watering costs of installation has already had two repair bills of more than 1000 euros in about seven years.
I have looked into GSHP’s and ASHP’s for my existing home, a Victorian end terrace cottage, as well as for building a new house.
The big downside for existing home owners it that you need to spend several thousand pounds on making your house super insulated; and I mean insulated so that virtually no heat escapes (or intrudes) even before you consider ‘environmentally friendly’ heating or cooling methods.
Insulating UK Victorian stock simply isn’t an option as they were built using open fires and chimneys as a means of whole house ventilation. Seal them up and they get damp because no matter what you do, warm air always meets cold air at the juncture of Victorian brickwork and modern insulation.
Passive Haus standards of insulation can be achieved with modern building methods and materials but they are expensive and what’s never mentioned is that they still need ventilation. That means mechanical air movement 24/7/365 which costs money as it uses electricity to run the electric motors that run the fans, to push the air around the building.
And it’s all very well building earth rammed or straw baled houses but they are all blighted by the same problem every other dwelling is, cold external air meeting warm internal air in a confined space which creates condensation.
Ventilation is the answer but it costs money if we don’t accept that natural ventilation is cheap. And I’m afraid that means draughty windows, doors and chimneys.
Living in caves with roaring fires wasn’t perfect, but like anything else, more sophisticated dwellings comes at a cost.
Bucking the laws of nature is tough.
I have had an ashp installed in my house for 7 years now. I’m off gas grid in a barn converted in th 1970s. With solid walls. No open fire. The ashp keeps the house sufficiently warm. And the running costs are comparable to gas.
Yes the rhi helped but the price to install has become cheaper as more companies are manufacturing.
heat pumps are all nice and good, except when it gets real cold. Then its electric heat. My house begins to use electric heat with an outside temp of about -4C. As the UK national grid barely makes it through winters now, I imagine that blackouts will be the result of more heat pumps and fewer gas heaters.
Heartily agree. Planners completely ignore these salient facts
There is no mention of one advantage that the proposed alternatives have over the gas fired units: they do not have the inherent hazard to cause explosions and or CO poisoning in the event of a gas or flue leak.
There is no mention of the deep (10m or more meters) coil geothermal heat pump, probably the most efficient and the one requiring the least thermal backup.
It is not clear why the biomass wood pellet boilers offer the largest savings (~ £855/yr) since the pellets cost about the same or more as gas (say, per unit of thermal output) and they do require preventive maintenance and ash disposal, Additionally, this type of unit emits pollutants (please note that CO2 is not a pollutant) like CO, ash particulates, unburnt hydrocarbons, NOx and other gases, particularly during warm up..
I susoect the better savings from bio simply relects more subsidy via RHI
RHI is intended to offset some of the extra costs of each technology, so if bio is more expensive than heat pumps, the subsidy is also higher
As an indicative guide, the installed cost of a horizontal gshp system is likely to be in the range £1,250 – £1,750 per kW of capacity, with that for a vertical borehole closed-loop system in the range £1,750 – £3,000 per kW.
https://www.gshp.org.uk/ground_source_heat_pumps_Domestic.html
Perhaps why boreholes are not first choice?
Supposing you live in a block of flats, will air source heat pumps to be attached to the outside walls of each flat, or would there be one huge installation on the roof.
Like all means of curtailing CO2 output, at least in UK, these costly measures must be dropped as irrelevant to global needs, if there are any.
Reblogged this on ajmarciniak.
That’s a lot of extra electricity generator capacity needed.
Reading around and interpreting power bill figures it seems that compared to gas heating ASHP users generally double their electricity usage. A heat pump seems to need 5000Kwh per annum (most in winter), the vast majority of this additional power will have to come from gas generators at 50% overall efficiency, with these figures, a national 100% conversion from gas to heat pump will need less gas overall so will indeed reduce CO2 release. I expect the government are thinking that a few more windmills in the North Sea or solar panels on the roof is all we need which make their target reductions look even better.
An interesting real life description of minimizing the costs of using an ASHP by matelodave can be found here in the comments. https://forums.moneysavingexpert.com/showthread.php?t=5601868
Cold (sorry, lukewarm) water, only just warm enough at best, 2 days to reheat the house if the heating turns off for a period hmmmm
Then of course on top of this we will all be charging our electric SUV’s………..
All this fuss for what has so far added only just over 1% to the components which cause atmospheric back radiation since pre-industrial times
I have not read the detail, but I find it hard to accept that an air sourced heat pump is more expensive to install than a water sourced heat pump.
An air sourced heat pump should be the cheapest type of heat pump. In Spain, an air sourced heat pump (split inverter system) can be bought for about Euro 300 (for a bedroom), and between 500 to 800 Euro for a lounge (depending on size). Installation is typically about 200 Euro (per unit) in a detached property with easy access to outside walls. It would be considerably more if one had to run piping underfloors or through ceiling spaces etc.
So for a 3 bed detached property, fitted with 4 small units and one large unit, it would cost about 3,000 Euro.
The problem with air sourced heat pumps is that their efficiency depends upon ambient air temperatures. They are not very efficient when the ambient air temperature is below zero degrees, and I seem to recall that they had no efficiency at about -5 deg C.
In Spain, the ambient night time winter temperature is probably between 6 and 10 degrees C, and at 8 degrees C, they are reasonably efficient. In the UK, the low ambient night time temperatures render air sourced heat pumps not efficient and therefore largely a waste of money.
I can advise that wood pellet burners are very expensive to run, and most people do not have storage space to buy wood pellets in bulk.
The proposed scheme is madness, just like most Government schemes are.
Strange calculations… Here in Denmark, most new homes have run on heat pumps for the last decade and with no major issues. With at average heat delivery at COP of 4, it’s considerably cheaper that gas – But then our prices are somewhat different.
I’ve never had issues with my heat pump, and even if it drops the COP to about 3.2 on the coldest of days (-12C), it’s no problem at all.
Our gas prices are about a fifth of electricty prices, so with a COP of 3.2, gas works out much cheaper
Scale it up and run power stations with this tech, then send us the electricity 😆
Slightly off-topic:
While perusing the FBI figures for crimes against property in the USA in 2017- expressed in crimes noted per 100,000 population – I pulled out the following:
San Diego 1,842
Los Angeles 2,535
Seattle 5,258
San Francisco 6,168
I feel the need of a $100,000 grant to do some computer modelling. I have already written the first line of the paper:
“The effect of Man Made Global Warming is, so far, greater in Northern California and contiguous States than in Southern California. The causes for this are not entirely clear, but preliminary study has yielded some interesting lines of enquiry. These should be pursued with the help of a whole University. It is a matter of some urgency since – obviously – the multiplication of crime further South, in the absence of decisive action against diesel cars, will result in a net economic loss of $33.445 billion just in downtown Los Angeles in the year 2033…”
‘Are Heat Pumps Cheaper To Run Than Conventional Gas Boilers?’
Doesn’t matter. It’s none of the national government’s business. The people – the marketplace – will decide what matters to them.
Interesting experiment in New York.
Oil seems preferred to heat pumps when gas is denied.
The elephant in the room is that electricity costs will keep rising far faster than gas as it is subject to government stupidity and taxes. I had a problem with my pond pumps and ended up turning them off pending a repair I haven’t done yet – and murky water makes it harder for herons – and was stunned by home much my electricity use dropped.
Meanwhile in the Netherlands:
https://www.hollandtimes.nl/articles/national/the-netherlands-to-go-completely-gas-free-in-the-future/
I note they are “encouraging the purchase of small-scale sustainable installations via the Investment Subsidy for Renewable Energy (ISDE), a subsidy for the purchase of small, gas-free appliances. These include solar boilers, biomass boilers, and pellet stoves – which can be used to heat homes incredibly efficiently”
It’s back to the Middle Ages then!
I fear in any densely populated area that in winter there will be a potential for creating a permafrost layer in the soil which might build over the years creating all kinds of problems, including freezing the local water mains and even the sewers!
That’ll solve global warming then, seeing as most of the warming is due to the urban heat effect!
Heating a house from backyard ground heat means there is a net loss of thermal energy from the ground. What thermal conductivity from below is needed to replace this and has it been established to exist?
We know how much energy a home gas furnace generates. How much ground volume does this represent?
Does the ground go “cold” after 5 years?
I asked heat pump installers in Calgary this question several years ago. They wouldn’t answer.
It’s the same problem that has been encountered with work on ground cooling ducts in hot countries. The calculations are carried out using undisturbed ground temperature profiles – after a period of time these equilibrate and the temperature source is not as obliging as first predicted. This will happen with a ground source HP, but if there is plenty of water around it shouldn’t be much of a problem. The heat transfer comes from above, not below as the geothermal leakage rate is generally negligible.
Heat pump technology is changing fast and are becoming considerably more efficient each year. Yes, it wasn’t a realistic alternative just 5 years ago but a lot has changed.
We have a 300 m2 house, originally from 1927 and renovated in 2009. Ground floor has in-floor heating and the first floor has normal radiators.
A year ago we changed from a condensing gas furnace (it broke down and I don’t want to spend money buying dead end tech and be reliant and Russian gas) to the best air-to-water heat pump you could buy at the time with real COP around 4 (Vølund F2120 20kw). It supplies all of the heat and hot water in the house.
We have saved approximately £1000 in just the first year alone and it’ll have paid for itself in about 7 years. We used to use £2000 each year on gas and last year we’ve spent less than £1000 on electricity for the heat pump.
It also had no problem supplying enough heat even when it was -10C outside – and that is without using the auxiliary heating cartridge…
I got involved in practical installations of air-source heat pumps during the 70’s oil/energy scare. I’d say this:
[1] a device who’s output reduces as the outside air temperature falls is not a good fit with the load.
[2] It is not sensible to connect an air/water heat pump to a ‘radiator’ heating system, hence the retrofit potential of these devices is minimal.
[3] Say what you like about the reliability of condensing boilers (mine is exemplary), data on air-source heat pumps is not reassuring. I know fridge/freezers are trouble-free, but they operate under fairly constant conditions. Also, it’s worth looking closely at the effects of defrosting on the seasonal efficiency of air-source heat pumps.
air source heat pumps ?
Is it some kind of magic
Or do they suck in hot air in the day and then release it at night.
#2 All installations that rely on huge amounts of extra infrastructure and say they will make a playback in 20 years, are basically front loading the CO2 footprint into the construction stage.. And are therefore increasing today’s CO2.
I started down the route to heat pump for my large grade 2 listed Georgian property. First hurdle was requirement for secondary glazing as double would not get planning permission. The heat pump salesman also represented a certain well known home improvement glazing company and rapidly talked me into signing up for a survey. He did not point out that hidden behind the first page of the survey contract were two more pages in 7 point faint blue on blue paper of clauses committing me to the full price with only 7 days cool off. I did not realise my mistake until their surveyor did the full survey and priced it at £14,500. I was informed in no uncertain terms that pulling put would cost 30% of the price. I pointed out that without planning permission nothing could be done. But hidden in the small print was another onerous clause placing all responsibility of planning permission on me or them at my cost. We settled out of court. MORAL. Don’t sign any blue forms from a certain double glazing company. And don’t even think about ground source.
Thirdly, Ted, remember the catches in “NEW LAMPS FOR OLD,” which fools so many of those in charge in the corrupt green scams!
High indices of suspicion called for.
Very best wishes, Charles W.
The COP drops as the outside temperature drops and “below about minus 2℃ a heat pump would need supplementary heating” to maintain the inside temperature. Below minus 7℃ the COP is more likely to be 1.0 i.e. no more efficient than an electric radiator.
These are from the USA where outdoor temperatures are much lower and houses are well insulated. Fortunately we know from previous predictions that from 2010 it won’t get cold enough for there to be snow in England.
Those numbers are for old obsolete heat pumps. For an air-to-water heat pump COP depends on the efficiency of the heat pump, the outside temperature and the temperature you want to heat your circulating water to. A top end air to water heat pump has a real (that is independently tested) COP around 5 in optimal conditions (+7C outside and 35C water temp). It goes down to around 3 at -10C.
Of course it’s lower if you need a higher water temp – which you do with a house that’s not well insulated or with radiators with a small surface area. Typically around COP 3,5-4 at +7C down to COP 2 at -7C.
Like I’ve written above, we’ve halved our heating bill by changing from gas to heat pump and it has no problem delivering plenty of heat at -10C without supplementary heating at all. The proof is in the pudding…
First point … I like CO2.It makes the food we eat and provides the oxygen we breath. It travels complicatedly between sea and air and earth and rocks in one great big cycle. It is part of the planet and its atmosphere.
I notice something a little strange going on. You will see it also if you just step back a little from the coal face of trying to reason with pure science against people who have no care about science unless they can find a minute detail of one partial dataset which after massaging and homogenizing and pasteurising and looked at in a darkened room by candle light on Halloween sort of supports one small part of what they claim is happening if you look at it with a squint through a glass eye.
Joking aside and if this was not so serious it would be funny. However, Mambe I am stupid BUT…………given that the majority of CO2 produced by human activity in the world is in India and China…… why are we doing this to ourselves in the UK? We represent 1% of the world CO2 production.
IF, just IF there really really REALLY is a problem in 12 years time and the world will end or at lease go horribly wrong, do you REALLY think nothing serious would be going on right now except for virtue signaling by politicians and screeching by marxists pretending to be environmentalists ? If there REALLY was a problem would be seeing the story line of Independence Day or one of those other nonsense disaster epics with Putin and Trump hugging eachother weekly.
Think for a moment, why is ANY investment going on at all if this 12 year thingy is real? Why are mortgages for 25 years and 30 years still freely available? If anyone knows a risk it is banks and insurance companies. I have a house RIGHT NEXT TO THE SEA. I can throw a stone into it. Mortgage absolutely no problem. Insurance also. if all of what we are told is even 5% true the banks and insurance would not touch it with a barge pole.
If there REALLY IS a problem and India and China are pumping out the majority of CO2 surely they would by now be being ordered at a point of a gun to stop? The fact that this is NOT happening and in fact there is an almost total silence about it speaks volumes.
We have exponential population growth that the marxists pretend is not happening, except for marxists like Occasional Cortex who tells people in the West ( notice not the third world) that they need to consider not breeding. A worrying fact. There are more people alive today than have ever died….chilling.Anyway, IF we accept that mankind is responsible for global warming and by a leap of the same irrationality, climate change then there must be a relationship between population and global warming…more people more global warming. If the problem IS real and it IS caused by man why is third world breeding going on without a murmur by the marxist do gooders unless of course there is an ulterior motive
We also have a skewed business market in the West with unscrupulous and devious people making a fortune out of governments who cannot wait to throw our money at them if they say “Green” or “Sustainability” or “Eco”. These companies are fueling the fear industry to hide the total dodginess of what they are doing “Bitter medicine but it is for your own good”. How else do you have the perversion of Drax which after a very costly refit burns wood pellets from America which travel on DIESEL POWERED BOATS! Wood pellets which per therm of heat produced release far more CO2 to the atmosphere than coal. There are now highly efficient and clean coal burners so doing the maths why are we not burning coal? We are told that wood pellets are carbon (I so hate that ignorant term) neutral. Yes just think, all the energy consumed cutting down trees and bringing them to processing mills then putting them on diesel ships and burning in Drax. Yes we are told that burning a tree in one second and planting another which takes 50 years plus to mature balance each other out so everyone smile! Who is doing the maths here?
If I was not so stupid I would think therefore that this is nothing to do with climate but is pure leftist subversion in bed with the very worst of capitalism, just part of Critical Theory being played out and the UK Conservatives cannot join in the fun fast enough!
So I must be stupid!
Air source heat pumps work, and are fine. They have their advantages and disadvantages, just like any other piece of equipment.
That said, tearing out a perfectly functional gas heating setup to install heat pumps makes no sense at all. Heat pumps aren’t garbage and they aren’t a magic bullet to “save the planet”. It’s just another appliance that may or may not be the best tool for the job.
In the UK there most certainly is a piety premium on the subsidised heat pumps and the required certification for approved installers (and manufacturers) is just farcical – it doesn’t guarantee performance – it merely anoints members of the overcharging club.
While researching water to water heat pumps a couple of years ago I found approved installers and manufacturers overcharging massively.
There is far more skill required to correctly size and position a heat pump than a traditional boiler and it is usually simply beyond the average heating company who want to get into “Green Power” – there is a lot of buyer remorse out there.
When integrated into the building design there is a better chance of a good outcome – retrofitting… there be dragons.
There was a project in Denmark to research heat storage from rooftop thermal solar to the ground underneath buildings started about 4 years ago – it sounded like a good idea – I’d love to know some result a.
TomO:
from an enthusiast.
“Today Vojens is known to be the solar city number one. The local consumer-owned district heating company Vojens Fjernvarme is in 2014/2015 in the process of establishing the world largest solar heating plant (70,000 m2) and the world largest underground thermal storage pit (200,000 m3).
The huge storage will be operated as an interseasonal heat storage allowing the solar heating plant to deliver more than 50% of the annual heat production to the network. The rest of the heat will be produced by 3 gas engines, a 10 MW electric boiler, an absorption heat pump, and gas boilers.
The storage is excavated in an old sand pit. The 200,000 m3 water volume will be seperated from the district heating water by a heat exchanger. A huge “plastic bag”, formed by a special welded plastic liner, will ensure that the water does not dissapear into the sand and remains clean. The surface of the water will also be covered by the liner and moreover an insulated cover and draining system to remove rain water”.
Further advice is that the plant has been in operation for 2 years and has met expectations.
I don’t think one would fit in your back yard.
I’m sure someone has already said this, but I’ll say it anyway. The more you shift from any form of heat other than electric TO electric, the greater the number of people are at jeopardy with a grid failure. A black start will take days, and if you “choose” the beginning of a “cold snap” to crash your grid, you are looking at days on end without heat at all, save maybe those few fireplaces that are still functional – assuming you can find fire wood. And just how many people die from hypothermia over, say, a 5 day period without heat or even hot food in an all electric house?
Do you really think that a government that ignores the will of its citizenry isn’t capable of freezing them to death? Old skilled labor is expensive, new, trainable labor is cheap and plentiful.
Gas boiler units require electricity for controls / sensors etc dont they? The gas line pumping stations, while they are gas turbine? still have digital/electrical controllers , maybe they have battery backup ?
Exactly.
In fact you’re less vulnerable to outside factors with a heat pump. You can always use a backup generator for power, but if the gas supply is cut or the prices skyrocket during an international crisis with Russia there is nothing you can do…
Heat pumps attract 5% VAT. Perhaps if government want to encourage their uptake they should build lots of nuclear power so that the general population isn’t concerned about energy insecurity which certain!y seems to be the case at present, what with failed agreements to build nuclear and over reliance on itnterconnectors to Europe.
They should also consider lower electricity costs to power heat pumps perhaps via a separate circuit and meter.
On a frosty still morning with a an air temperature of 0’C and a modern estate of 350 per Ha and a house volume of 200 m3 using heat pumps to raise the temperature by 12’C then the outside temperature will have been reduced by 5’C to a height of 15metres by my back of an envelope and pencil calculation.