Thursday 3 November 2022

Heat Pumps Ahoy

Green Blob, personified
As we all probably know in the back of our minds, the Green Blob** plans to make us scrap our gas-based home heating rigs in favour of heat pumps, and that one day we shall perhaps need to think about the subject.  For the privileged few, this might be a ground-source HP, but for most (including new-builds, which rarely have enough land, if any, these days) it will be an air-source HP.

I'm starting to read my way into this, and am running into massive promotional propaganda on the one hand, and serious skepticism on the other.  Unsurprisingly, I find myself somewhat averse to the cheer-leading.

Does any reader have knowledgeable contributions to make?  (On HPs, that is: I know you all have definitive views on Ukraine, Covid etc.)



** Somehow, whenever I hear "Green Blob" it's always a vision of Gummer that comes to mind.  I just can't take that man seriously - I know it's unfair ...


Anonymous said...

This is an interesting look at air air-source heat pump installation:

I'm sure in modern new builds heat pumps can work. For older properties this will be more difficult to retrofit, unless you were doing a complete do over of the whole house

Swiss Bob said...

Got a ground source heat pump (a lattice of pipes a metre under the lawn) here in Switzerland. Neighbours had same too until pump packed up and moved to an air source one as cheaper to replace but they regret it, it's costing them more to operate.

But the trick is the houses here are often well-insulated. A sunny morning and the house heats up all by itself and stays warm. The pump is more a top-up for cloudy days in December-February.

Having owned and rebuilt several UK homes, it's very different with the sash windows, thin bricks, some basic lagging in the loft. The starting point really ought to be comprehensive insulation but it's not easy, you can't clad a Victorian brick-built house without altering the character. Then you get to the specific problem of heat pumps as the output is not as hot as the typical gas boiler so you tend to need bigger radiators - or better underfloor heating - so a simple swap is harder.

Imagine there's a handy market for UK specific pumps that produce at a higher heat but this gradient, and the lack of insulation, means an air pump is going to be on a lot and that won't be cheap.

Clive said...

At the risk of incurring cave dweller ire (okay, that’s a bit unfair; there are legitimate concerns about heat pump issues and EVs too etc) I have had ASHPs installed. So I can do that rare thing, actually comment from experience, albeit anecdotal, rather than just the usual pro- or anti- greener technologies talking points.

First, there’s little point trying to solve a heating energy use problem without doing all you can to insulate the space to be conditioned. I had triple glazing installed first and my house is 1996 vintage so otherwise is fairly good in terms of other building fabric being s lemme to keep the indoors and outdoors thermally separates. If you have a solid wall or other hard-to-heat structure, you’re always going to struggle with heat pumps. But then you’re already struggling with your combustion heating, you just don’t know it because you can simply throw more energy inputs at your problem.

But if you have a reasonably airtight house then heat pumps work fine *for the most part* in my experience. There is one important caveat. When I had the heat pumps installed, I but the bullet and changed out the heat emitters. The industry is coy on this whole subject and there is a lack of education amongst both installers and consumers about how meet to get the heat distributed into the conditioned space. Radiators are usually deemed appropriate but often as not the advice is to increase the size of the radiator to cope with lower water temperatures.

This always struck me is the wrong approach. With low leaving water temperatures (50 degrees or even as low as 35 degrees centigrade as opposed to 70°C for a combustion boiler) radiator based heat transfer is never going to be optimal. So I had fan coils fitted instead. This has a useful bonus of being able to provide cooling, if needed, as well as heating. I had to do a fair bit of redecorating afterwards.

The other thing to keep in mind, even if you sue can coils as the heat emitter, is the way the heat is transferred into the conditioned space isn’t what most people are used to. You just don’t get that nice warm blast of heat from a hot surface like you do when you switch a combustion heating system on. It’s a gentle background heat. While the space will get warm, it doesn’t, subjectivity, “feel” as warm, even at the same thermostat setpoint.

Could talk much more about this subject, but think that’s enough to be getting on with. Apart from to add that, if correctly designed, in a well-insulated building, a heat pump will be, from what my bills tell me, at least a third cheaper to run. But that’s still not enough for a payback that’s measured in anyway other than geological timescales.

Matt said...

A lot of UK housing stock can't use heat pumps without extensive (and expensive) modifications.

Payback period is long vs the existing throwing more energy inputs at your problem that we are used to with hydrocarbon based boilers. From what Clive says this is the case even if your house is more adaptable (well insulated/conditioned).

Government ignores the above and legislates with the hope that something will turn up in time to address the problems.

In other words, the same insane wishful thinking that underpins the rest of the climate change crap that parliament has burdened the country with.

Anonymous said...

If you have an old place, prepare to move out while the internal walls are insulated. Or the external ones, but then you may have issues with damp staying in (we have no foundations and internal rising damp in walls is an issue - not major but it's there. Clay paints are expensive if you want to stop wall paint flaking).

We run on oil for this reason, £1800 last fill! Thanks Biden, Nuland and Co!

I know someone in an old Dales barn with air source, but it has hefty internal wall and roof insulation, underfloor heating downstairs, big radiators - and while it's pretty comfy, it's not had a real cold winter yet.

I know someone else in a big old Irish place, massive ground source pipe system, says it never really gets very warm upstairs. But in Cork, very few bitter winters.

Anonymous said...

(cont) I should say when we moved in it was powered by a solid fuel Aga plus rads and had single glazed metal framed windows. So my kids had a few years of ice on windows in winter, til we extended, added oil heating and double glazing.

Anonymous said...

Heat pumps can and do work. The question is, how expensive are they compared to Gas heating.

Your Heat pump still has to be supplied with electricity. At the same time as the Grid is expected to supply all the EVs too, which we already know, it can not.

So, is it a sound idea to add additional burden to the National electricity grid, when we know it's already stretched to supply existing demand?

And ...

As if one hadn't learned the lesson of a monopoly supply, putting all your domestic energy supply eggs into one electricity basket, really doesn't strike me as a sensible idea.

Anonymous said...

I think an interesting technology in this area for the UK is gas powered heat pumps (e.g.

Or combining gas driven micro-turbines electricity generators where the excess heat is used as an input in to the electrically powered heat pump.

In theory much more efficient than centrally gas generated electricity (60% efficient) driving an electric heat pump.
As you use the excess heat from the turbine as an input to the heat pump. And will work better with the UK’s housing stock as the output temperature is higher.

A potentially promising staging technology until the UK completely transitions out of Gas.


Clive said...

@ Matt 12:50

The payback, or lack thereof, is an interesting if vexing question.

On the one hand, it's a bit rich to criticise governments, regulators and the usual suspects we point the finger at for short-termism if we, ourselves, as a society, don't think much beyond the next 3-5 years (say). Houses last a long time, or they should do, anyway. I've seen it said that homeowners should budget for 2-5% of their home's value per year for maintenance and capital renewal projects. So for many, a £10-15k heating system upgrade isn't a big ask. Certainly round my way, £20k+ kitchen refurbs are, if not the norm, then probably the average. And these are done every 15-20 years. And a gas or oil boiler will last 15 years typically. You might stretch this to 20 if you're lucky but then you are starting to push your luck. Even a drop-in, like-for-like boiler replacement is £3-4k.

So given an opportunity, if you're looking to have to replace a combustion boiler anyhow just because it's life-expired, I don't really get this kvetching about the cost of heat pump installations or the payback times. Of course, if your boiler is only a few years old, it's a different question, but there's a lot of factors to consider -- which is why I'm wary of knee-jerk one-size-fits-all generalisations. The merits, or not, of switching to a heat pump is fact- and context-specific. Saying "oh, if a dumb idea" or "oh, everyone should just go right ahead and do it" is a little moronic.

The key determinant of the payback time is the cost of energy. A few years back, it seemed there was little to no financial case for having a heat pump. Even at their most efficient in a well-insulated house, they were only marginally less expensive than a combustion boiler and the fuel cost (gas being about a third the price of electricity) ate into the inherent energy efficiency saving benefit.

But that was then. Now, with natural gas prices at c. 11p / kWh my air source heat pump's Seasonal Coefficient of Performance of 4.5 or more (when combined with fan coils able to use 35 degree leaving water temperatures) mean that even though electricity is c. 30p / kWh I'm quids in fairly substantially every minute the system runs. If I, in effect, write off the capital outlay as a sunk cost (it was just having to skip a couple of foreign holidays in terms of opportunity cost) then I'm saving at least a hundred pounds every month October - March. In fact, it gets even better because I've also switched to an "Economy 10" tariff. On that, I pay an eye-watering 40+p / kWh for 14 "on peak" hours" but only 12p / kWh "off peak". Economy 10 includes two blocks of time in daylight hours (not just overnight like Economy 7) so I can heat the space to a comfortable temperature that usually lasts until the next "off peak" time slot at that 12p / kWh rate. When you consider the heat pump's efficiency is 450%, that makes each kilowatt of heat cost about 3p. Frankly, I'm laughing at that when I see the plums of combustion gasses rise up from the flues of neighbouring houses.

Like I say, though, and I can't say this enough, it really does so much depend on what your circumstances are and what proposition you're considering where heat pumps are concerned. Getting to the bottom of that is hard enough. That's before the problems of there not being anything like sufficient trained -- and honest -- heat pump systems designers and installers around. As Nick hinted at, there's a lot of cowboys and snake-oil salesmen around. Not just in terms of installers, but in manufacturers, government and the green lobby, too.

Matt said...

@ Clive

I see the economics argument in very simple terms:

If there was an obvious economic benefit to installing heat pumps, people would be doing it to save money. The fact they don't and government has resorting to banned conventional boilers tells me that it doesn't in fact make sense in economic terms.

Sure, it might in terms of Saving Gaia but that's a different argument.

jim said...

In a word 'don't'.

I have tarted up a few houses and wielded a plumbing torch a few times. I know a little - too little.

The following websites look to have useable info:-

Overall it looks a great deal of bother and expense - especially a retrofit. My house is like many, a mixture of Victorian labourer's cottage and two generations of extension. Pipes glued on to pipes glued on to a system put in in the '70s. Chipboard floors with carpets and fitted wardrobes to shift....

The usual numbers for heat pumps run about 4 to 5KWh output for each 1KWh electrical input. Whilst my elderly boiler was rated at about 40KWh. Although it seems to cope except on very cold days. Here in rural Kent not unusual to see -16C on a cold winter morning. The usual calculations based on -1.5C.

Which brings us to boiler output temperature. Mine is about 80C say whilst heat pump systems get to about 50 to 60C. Which means either a cascade system to push the output temperature higher - more electricity and a bigger first stage. Or bigger pipes/radiators etc. Mrs J does not like tepid baths!

Then the below ground temperature. Toasty at 6000 metres and about 30C at 100 and say 14C at 20 metres. No one is going to bury pipes in trenches at 20 metres. 1 metre max and for dodgy installers say 10cm if you are lucky. A few cold snowy weeks and there won't be any ground heat to be had.

A headache from now to doomsday.

Sackerson said...

There are more than 3 million 1930s houses like ours left in the UK and they were built for coal fires. Converting to gas still means a flue - and two if you have altered it to a through lounge, as so many do. And then British Gas made us put a third hole in the wall for 'safety'.

The house dimensions are excellent - much better than the rabbit hutches modern developers make; but for long term thermal efficiency we will need a rebuilding program. In fact if the house is sufficiently weather tight and insulated there should be not much need for additional heating since the average human body is (I'm told) equivalent to a one-bar electric heater.

Bill Quango MP said...

Builder in just yesterday. Looking at adding an internal, double glazed door, across the porch.
In the end, opted for a curtain across the corridor. Just too expensive.

However, he had just installed an air sourced heat pump at his mother’s. Said it was very warm, working very well.
Next door to me, only JUST replaced their economy 7.

The, you should budget for, I don’t buy into. If you were staying put for fifty years, maybe. But very often adding a new kitchen would reap an instant benefit. An air pump, would add nothing. So spend your £ where it counts.

If these energy prices are the new normal, all will change.

Clive said...

@ Bill Quango MP

Yep, that’s the nub of it. When I had to decide the matter, I asked myself for how long did I think it viable that we’d be able to get away with paying 3.5p / kWh for natural gas. I concluded it was nice while it lasted, but it wasn’t going to last forever. For my money, literally, the days of 3.5p / kWh are gone and they’re not coming back.

A few years of natural gas at 10-15p / kWh will make a lot of people think a lot more seriously about a combustion boiler chugging away guzzling 20-40 kW for hours and hours a day.

I could throw in secondary effects such as the number of homeowners merrily adding square footage of conditioned space to their properties (or buying large houses in the first place, or single pensioners living in their former family homes now they’re on their own through the death of a spouse and the kids les ing home) scarcely considering he cost of heating it all or even not considering it at all. Full disclosure: a pet peeve of mine are those huge flat roofed extensions people sling onto the back of their houses as kitchen/family rooms looking like a portacabin has landed in their back garden. They usually have the thermal envelope of a wet paper bag. Especially when, as they often are, comprised of large glazed areas e.g. bifold doors. I have a hunch they’ll regret their cheap and cheerful extra 500 sq. ft. of warehouse-like accommodation if energy costs remain at these elevated levels.

E-K said...

"Even a drop-in, like-for-like boiler replacement is £3-4k."

Clive. That is not correct. I did mine three years ago for £1,800, a Bosch Worcester.

I agree with BQ on the kitchen being a wise spend. We've had ours done and fitted energy saving appliances throughout whilst doing it - including LED light fittings.

Payback times are important. They must be weighed against longevity. An electric car, for example, is more likely to be sold on before it's given the buyer his savings.

E-K said...

I don't think there will be a choice to go for £25k plus heating systems.

People will learn to lump being cold and feeling poorer, however hard they work or however hard they've studied... which means a Labour government is coming.

The Tories have nothing to offer but the bitter chill of ice cold austerity... to working people, that is.

Clive said...

@ E-K

Three years ago might as well be in the stone age when compared to the cost of both boilers and, especially, labour, today. If you have a combi, that's cheaper to do a swap out, but a system boiler or heat-only is more, certainly £3k and if you want the manufacturer to honour the warranty you'll need a system clean and a magnetic filter which bumps up the cost. Two friends have both replaced their boilers, no quote was less than £3k, most in the £3-4k range or even £5k.

Yes, you can get some low-bid installers but you can easily end up with a hack job (or worse, an unsafe installation). Of course, you can pay full whack and get rubbish, too.

I can guarantee you, no-one, certainly not in southeast England, will do a new boiler for £1,800 today.

Anonymous said...

OT - economist Michael Hudson on the coming German industrial disaster.

The country suffering the most “collateral damage” in this global fracture is Germany. As Europe’s most advanced industrial economy, Germany steel, chemicals, machinery, automotives and other consumer goods are the most highly dependent on imports of Russian gas, oil and metals from aluminum to titanium and palladium. Yet despite two Nord Stream pipelines built to provide Germany with low-priced energy, Germany has been told to cut itself off from Russian gas and de-industrialize. This means the end of its economic preeminence. The key to GDP growth in Germany, as in other countries, is energy consumption per worker.

These anti-Russian sanctions make today’s New Cold War inherently anti-German. U.S. Secretary of State Anthony Blinken has said that Germany should replace low-priced Russian pipeline gas with high-priced U.S. LNG gas. To import this gas, Germany will have to spend over $5 billion quickly to build port capacity to handle LNG tankers. The effect will be to make German industry uncompetitive. Bankruptcies will spread, employment will decline, and Germany’s pro-NATO leaders will impose a chronic depression and falling living standards.

Most political theory assumes that nations will act in their own self-interest. Otherwise they are satellite countries, not in control of their own fate. Germany is subordinating its industry and living standards to the dictates of U.S. diplomacy and the self-interest of America’s oil and gas sector. It is doing this voluntarily – not because of military force but out of an ideological belief that the world economy should be run by U.S. Cold War planners.

Clive said...

@ Anonymous 6:36

Yeah, but Michael Hudson. Hudson might well have a point, somewhere in all that cant, but with Hudson, the anti-western storyboarding comes first, then the how's and why's of the latest "the US Empire is failing" tale of woe gets fitted in around it.

Germany has needed a new industrial policy for at least 10 years now, possibly longer. It was, like the UK in the 19720's much too comfortable with the one it had, despite the manifest shortcomings, to go through the process of trying to come up with a new one. Sooner or later the "buy cheap gas and sell high end stuff to China (and Russia, for that matter" was going to reach its natural limits.

Hudson ignores that the Mittelstand does have pricing power. Increasing prices will create demand destruction to a degree but that's a long way from the "deindustrialisation" and "chronic depression" which Hudson opines on. Oh, and Hudson has been saying this stuff for twenty years or more now. There's a reason you see him pop up so often on anti-west misinformation sites like The Saker, Consortium News and RT. It's his schtick and that's the market he pitches it into.

Nick Drew said...

Indeed: that Hudson stuff is bollocks. Germany has dug a hole for itself by its own crass-bad decision making, without any outside direction required: what with energiewende and wandel durch handel - in fact the Americans have been screaming at them to stop some of this nonsense: in the case of gas imports from Russia, for more than 30 years!

Trouble with Germany is, when they do anything - including digging holes - they really give it maximum wompo. But right now, they are working characteristically hard and uncomplainingly to extract themselves - and it's the French that are whingeing. "You can't spend EUR 200bn on fixing your problems - you'll distort the market against the rest of us!". Well. Just watch 'em. They spent EUR 1 trillion on reunification - again, without (much) complaint**. Did Macron think the biggest & richest nation in Eu was going to roll over and die?
** except in the villages where loads of Ostis were billeted ...

Old Git Carlisle said...

Many years ago it was floated that domestic gas powered chp be adopted and some trials were carried i
out, If I recall correctly fell down on initial cost combined with potential maintenance costs. Was theoretically a very sound proposal.

Bear in mind the incompetence of the initial condensing boiler installations where the condensate was taken away on external drain which froze .Understood there were 50,000 call outs for loss of heating. At least the cowboys who built my present house run drain inside house.

There appears to be issue on the working fluid for heat pumps can't recall detail but a very potent greenhouse gas )or ozone destroyer),

If other recent installations are like mine the control systems are poor. My hall radiator is not equipped with TRV and shuts down upstairs zone. The manufacturers manual says the boiler has an internal bypass so TRV could have been fitted.

What is needed is some sensible review of all these matters and a few technically competent politicians and council officers.

E-K said...

I know a guy who will fit this for me for £900 and he's not a mate.

So that's £2k total.

dearieme said...

The only house with a heat pump that I've visited was in NZ. My pal liked the HP because he could use it for heat in winter and A/C in summer. Mind you, this was in temperate Christchurch on South Island so his alternatives in summer would be to deal with his huge area of sun-facing window by (a) using shutters, or (b) blinds, or (c) curtains, or (d) just opening the darn things.

But (i) he was a Texan and probably just jolly well liked A/C, and (ii) he taught thermodynamics so probably was just delighted to own his own heat pump.

Clive said...

@EK 9:45

A 28 kW combi won’t cut it in a two-bath house, sized properly you need 40 kW for decent DHW flow rates (although you end up oversized for most heating loads) £2,250. Onsite labour at least a day, assuming no snags plus prep time and clean-up, minimum 10 hours, 15 more realistic, all fixed-price quotes I’ve seen are for a two-day job. I hate to break it to you, but in the Home Counties, you don’t get a Gas Safe engineer for less than £75/hr although there’s no shortage of east European “no paperwork” cut ‘n shut job clowns who’ll do it for peanuts, if you think it might be your lucky day,

So that’s £3k minimum and £3-4k isn’t ripping you off.

Again, it’s important to look at what you’re needing, what is being compared to what and whether the work will get a manufacturer’s warranty.

lilith said...

I expect some mad government of Net Zero (of any colour) will tell me I have to move out of my single skinned 1929 house so it can be demolished. As it cannot be made "energy efficient". I believe this climate fascism is being trialed currently in New Zealand....

"We are sorry Ms Lilith but you must now live in this properly insulated, fully of nasty chemicals, cold, purpose built garage instead."

Anonymous said...

I live a mile from the M25 and in Jan this year had my heat only boiler replaced with a system boiler (IDeal Logic Max 24Kw). Total cost £2500, this included system flush and magnetic filter.

Certainly wasn't a Eastern European fly by night job either

Anonymous said...

and this included upgrading the gas pipe from the airing cupboard to the boiler (in loft) with a wider pipe.

Nick Drew said...

Thanks, all - "great stuff, guys", as they say.

Plus this link, sent in by Elby (who hasn't read them all - and neither have I - but thought we'd like to add it to the pile)

dearieme said...

One bar electric fire? Too high by an order of magnitude. For ordinary indoor activity you'd be wiser to bet on a human adult giving off 100W to 150W.

'course if you kept an elephant indoors you might have less need for heating. 'specially if you put it on a treadmill.

Anonymous said...

And with the elephant you could probably burn the dried dung or get gas from a digester!

There is the small matter of feeding costs... or do you just take it to a series of aboreti, in an ever-widening radius as each is destroyed?

Clive, ND - what was the problem with Germany relying on Russian gas? If you missed it, it wasn't the Russians who cut NS2 off.

That gas isn't going to stay in the ground, it's going to end up in China or (possibly) back in Eastern Europe via Turkstream/Balkan Stream, perhaps mixed with Azeri gas one day.

Germany is shutting her nukes, where are BASF going to get energy from? They are shafted (and so are we btw, but we have less productive industry, Wilton and Runcorn a shadow of their former selves).

I see France's largest glassmaker, Duralex, is shutting down for five months.

E-K said...

Clive - I have a 29 CDi in a five bed with two shower rooms and one bathroom (the bath is rarely used) and it does just fine - one of the showers is an electric for sure (very handy when the gas is off.)

What 3 bed semi has two baths ???

It's a two day job to fit a boiler - @ £500 a day labour with the testing and certification (being generous)

£2k is realistic... but not if you go with British Gas direct.

A heat pump is an off the scale 'investment' and will never pay a return. I expect them to be ditched as a policy before long and buyers will live to regret them.

Gas boilers and ICE cars have been made to be deliberately expensive in order to make the green stuff look viable.

Clive said...

@EK 6:20

Yes, this is exactly what I mean. You can undersize a combustion boiler to trade off comfort for a lower installation first-cost. You can do the same with a heat pump.

And any bandying about of figures (be they equipment costs or rated outputs) is meaningless without specifying what the design conditions are and whether you're prepared to tolerate a lack of capacity if you've decided to under-specify your boiler when you actually hit a design-condition day.

Sure, 29kW will cope just fine on a mild winter's day, let's say 0 degrees C overnight minimum, 7 degrees C daytime max -- and you let the space temperature setback to, say, 15 degrees C until the timer runs the heating in the morning and you're willing to wait a few hours to get to a lowish 18 degrees C in the day. Plus you only run one shower (or fill a single bath).

29kW will certainly *not* be sufficient on a very cold winters day, maybe -5 degrees C overnight, the space temperature falls to maybe 12 degrees C overnight in some rooms and when the daytime temperature fails to crawl above 3 degrees C with no sun, everyone feels chilly sitting in less than 21 degrees C. A 2,000 sq. ft. house with mediocre insulation will have a heat load of 20-25kW requirement to try to drag the conditioned space up to the setpoint on that cold morning in anything like an acceptable time. If you try to run a shower, usually 8-10kW, a 29kW boiler will simply not have the required capacity if trying to keep on top of meeting the space heating demand. With only 4-5 kw of "spare" capacity after trying to satisft th space heating load, you'll get a trickle of tepid water, with water inlet temperature of maybe 4 or 5 degrees C and a delta T of 30-35 degrees C. Depending on the boiler, the diverter valve will probably open half way and you will get an okay-ish shower flow, but the boiler won't be able to maintain the space setpoint temperature in the kind of heat loss you'll have when it's below freezing outside. And forget all about trying to run a second shower fed from the gas boiler. Which kind-of makes having the extra bathrooms a moot point, if there's not the domestic hot water supply to feed them on the very coldest days.

Of course, what people in this situation of having cheap, but undersized, heating systems do is tell themselves they'll just put up with it for the (hopefully...) short while that a very cold snap would last. And aren't they clever for saving all that money on a cheap and cheerful, if under-sized, boiler installation. The tepid showers (or the inability to use multiple bathrooms simultaneously) aren't mentioned to anyone and soon forgotten.

Part of what you're paying for in a heat pump installation is a proper room-by-room heat loss calculation and an accurate load calculation (including the necessary stored water volume for domestic hot water). That's a skilled and time-consuming job. But it means your system is both a) efficient and b) adequately sized to ensure performance is guaranteed on a design-condition (i.e. very cold) day. You benefit from better comfort and efficient operation.

'Course, in the UK, the consumer mentality is, let's just chuck in a combi more-or-less guesstimating the variables and, if it works, mostly, that's fine. When there are issues, such as cold rooms or too hot rooms, or an inability to supply the required amount of domestic hot water, people simply put up with it, 'cos that's how it is, innit? As I've mentioned previously, that was fine, when energy cost 3.5p / kWh for gas any 10 p /kWh for the 'leccy. Now they've trebled those historic rates, even with the price cap, perhaps our good hosts here could return to this topic in the future, perhaps in March or April when those winter quarter utility bills are in. We can then see how everyone feels about sticking with the tried-and-trusted approaches they've relied on since, like forever.

I'm happy to show you mine, if you'll show me yours.

E-K said...

Blimey !

We've never been less that toasty - even in snow.

I've found an open plan house is actually better for heating. The rising heat is not wasted when it rises and we leave the bedroom doors open with their thermostatic valves turned down. We've never known hardship with this boiler size at all. Even the cooking contributes to the warmth of the house. I doubt the total efficiency of LED bulbs as the filament type helped keep the ambient temperature of the house up and was not wasted heat.

We are double-glazed, loft insulated and cavity insulated.

E-K said...

For all that... I'm still a cooool daddy.

jim said...

Back of envelope time. Out Climate Change ctte seems to think decarbonising our homes and businesses will cost around £250 billion. So from the numbers and guessimates we have on this blog does that make any sense? Take 28.5 million homes and 1.9 million businesses.

Say a domestic heatpump system is £25k basic plus say 10k remedial and financing and inspection prodnose costs. Say £40k for 28.5 million households. I make that £1140 Bn or £1.14Tn.

Then the businesses. On an 80/20 basis say 80% of businesses are smallish and might cost say £200k to fix. That's 1.52 million times £200k = £304 Bn or £0.304Tn. plus the remaining 20% costing much more at say £20m each. Making 0.38 million businesses at say £10 million each = £3.8 trillion. In total £5.24Tn, pretty serious money, but spread over say 20 years, a mere £262Bn/year.

Not looked at the Climate Change ctte numbers but I smell a problem.

Nick Drew said...

Jim - will need to join in with your highly pertinent reality-check calcs, & also cross-ref with the CCC & BEIS stuff on this

but 2 immediate thoughts: (1) maybe they, too, concluded £250 bn per annum!

(2) when you delve into some of these green advocacy numbers you find they've done something like

- deducted the cost of what they take to be the counterfactual, i.e. replacing with a new gas boiler instead and burning a heap of deemed-to-be-expensive gas

- debited the BAU case with CO2 offset at some exorbitant deemed future cost of CO2 allowances

i.e. the purport to calculate an incremental cost

Anonymous said...

"kind-of makes having the extra bathrooms a moot point"

It was more a case that when getting 4 kids to school and me to work, we needed the sinks at toothbrush time! Two bathrooms - one with bath/shower, one shower only. It was pretty rarely that people were bathing or showering simultaneously (but I think our boiler is 42 or 48 kw).

I put 2 sinks alongside each other in the "main" bathroom so that helped.

Thud said...

I installed air source in a couple of builds I disasters, would have been more efficient and fun burning money.

Thud said...
Last cottage I built, insulated to the highest standard we could achieve, heat source was useless even when we over specced.