Thermodynamics question

[Newbeeneil]

Time for me to say something!
I have lived in many old houses. They have been heated with gas, oil, totally woodburners and now the present one has an ASHP.
I can say that my present house is the most consistently warmest and most comfortable we have lived in. It was built in 1850 and has single skin walls. When we moved in it had an old oil boiler and an illegal oil tank so we had to spend money on getting it replaced. I did my homework and sought advice. I had three heat surveys and quotes done and soon realised there were cowboys out there. We finally settled on a company we could trust and had all the radiators replaced with larger ones. Insulated everything that needed insulating, had a proper sized ashp installed and have never looked back. That was six years ago. We also had PV panels installed at the same time which have supplemented the costs and last year had batteries which have also helped no end.
You have to do your research and get the right company. It is not cheap. I was lucky to be able to claim RHI which has paid ALL my electric costs for the whole house for six years but that aside the ASHP is not expensive to run. I have made sure that I am running it in the correct way (Weather compensation mode) that lowers or highers the temperature depending on outside temperatures. I have made sure I am on the most economical tariff when it comes to electricity. I have made sure I know how the system works best for my situation and am more than happy with the costs and the way it runs. I would never choose any other form of heating. No worries about carbon monoxide or filling tanks with gas or oil. You can produce your own electricity if you can afford the outlay. I long decided that although new technologies are expensive to put in, they help sell your house when you move and in our case have always added value.
You have to do your homework. You have to be prepared to spend money on insulation and on proper size radiators, you have to have confidence in the installer and you have to put some effort into running it properly. It is a big investment so get it right.
If you do all that you will live in a warm comfortable house for a reasonable cost. It is a different mindset to normal heating so be prepared to learn new stuff.
I am very happy to answer any questions on any of the technology or items raised if anyone wants to PM me.

Well put enrico, I would reiterate everything you have said especially with houses that do not have mains gas.
When we installed systems to replace gas the savings were marginal but when installed in rural properties they were very significant.
A mate has just moved into a small estate of luxury properties on the outskirts of my village and almost didn't buy the property because they had heat pumps. He now is an evangelist for the technology!

 

[user 20297]

Can anyone forsee a rise in dodgy inspectors?

I think that the accreditation organisations are already aware of some malpractice by rdSAP assessors and the scheme that I am registered with is very strict in doing regular audits of assessments. But where money is involved there is always the chance of corruption.

 

[user 20297]

Why? About what?

The philosophy that equality of access to disproportionate, state financed, energy saving measures does not matter as long as the minimal and theoretical, global energy savings are achieved is a concept that is rooted at such a distance from my own that I despair at finding a middle ground in discussion.

 

[enrico]

Just for the record solid stone thick walls are far more efficient than you give them credit for. They act as thermal stores in their own right and once warm will help keep temperatures constant. I have done lots of research. The only single skin wall I had to insulate were the 6inch thick ones. The 1 foot stone ones are fine.

 

[Erichalfbee]

You can add insulation board internally to create what is effectively a new box. I would make arrangements for the inside of the stone walling to air.

You lose a few inches of roomspace. But you get a climate controlled living space that will cost pennies to heat.

Yes. I suppose we could get the beams sealed off with a false ceiling. The windows fill the whole window recess so adding insulation would mean we wouldn’t be able to open them. So no I won’t.

 

[roche]

We are being persuaded to replace boilers with heat pumps as a national policy. In fact when my old oil boiler approached the end of its life I took the step, encouraged by Renewable Heat Initiative grant towards the cost. As my system has an Air Source Heat Pump which delivers hot water to the radiators at a much lower temperature than the oil boiler did the project included changing the radiators to one's with appropriately larger heat emission areas.
After using the system for a while it became evident that comfort conditions in the house were vastly inferior to the oil system. Response time to attaining desired daytime temperature from night time setback indoors is very much slower plus the efficiency of the heat pump drops off as outside air temperature falls. The response from most industry sources is to run with a setback only a couple of degrees lower than daytime so maintaining very little difference in heat loss indoors to outdoors.
I'm by no means a thermodynamics guru but surely this in/out delta t is wasteful and has a significant negative effect on the efficiency? Increase in insulation may reduce the losses but heating a building when residents are either tucked up in bed or out at work seems wasteful.
If Derek M reads this perhaps he can comment?

So coming back to the OP...my understandings are as follow, and I am willing to be corrected...I am pretty sure that the efficiency of heat pumps is best when the input and output temperatures of the pump have less of a delta t. So in order of preference the worst source is air source, followed by near surface ground source and the best is deep well ground source. Deep well with sufficient capacity should give a pretty consistent input of about 10C. Air source is all over the shop, and at its worst in the coldest weather. Near surface (think of an array of tubing buried up to about a metre deep) is effectively using the topsoil as a heat store, and can become discharged. It relies mainly on the sun to re-charge. Deep well sources are effectively geothermal. They can become discharged if a large demand is placed on them but will recharge without insolation. The down side is that drilling the wells tends expensive - I've never really figured out why.
Oil and gas have the ability to deliver huge amounts of energy in a very short time, whereas heat pumps tend have capacity constraints designed in, probably to do with the size of the heat exchangers required. Because oil and gas have this huge energy delivery capacity, they can get a house up to temperature very quickly, the comfort levels are high, and the shortcomings of insulation can be disregarded until the bills come in. Because heat pumps, whatever their source, have a limited ability in terms of high short term energy delivery, they cannot get a house up to temperature very quickly - you need to think about the ramp times and compensate times and temperatures accordingly. If the system is correctly sized, it should be able to supply the same amount of heat over time more efficiently (in terms of direct energy input) than oil or gas. Where it cannot supply heat fast enough is at high peak demand, like getting the house up to temperature in the morning, or the coldest days of winter. So the thing there is to reduce the heat loss of the building, using insulation. That means that the higher setback temperature can be held more efficiently, and there is a lower peak demand to get up to temperature quickly.
Ultimately the same amount of heat is required for a given comfort level. The amount of energy required to create that heat will be lower with a heat pump. The speed at which the heat can be delivered depends on the source. The amount of heat lost depends on insulation in either case. There is room for discussion about losses in the electricity distribution network against oil or gas....

 

[Beesnaturally]

The philosophy that equality of access to disproportionate, state financed, energy saving measures does not matter as long as the minimal and theoretical, global energy savings are achieved is a concept that is rooted at such a distance from my own that I despair at finding a middle ground in discussion.

Let me just take the opinion out and mess it about so we can try to read it without the judgement.

The philosophy that:... equality of access to state financed energy saving measures... does not matter.... as long as ...global energy savings are achieved... is a concept that is rooted at such a distance from my own that I despair at finding a middle ground in discussion.

This seems to hinge on the idea of equality of access, funded at state level, yes? Its anti-socialist? Its saying: if you can't pay the going rate (shoved up by people who can pay, that's ok?

And then: what is worse, this socialism is predicated on and justified by... a merely theoretical problem - ie man-made global heating.

And this idea: that we pay taxes to help poor people with their electricity bills (which are made higher by the subsidy of renewables) in pursuit of what could well be a phony goal (Net zero) ... is not something I agree with...

Is that right?

 

[Beesnaturally]

Just for the record solid stone thick walls are far more efficient than you give them credit for. They act as thermal stores in their own right and once warm will help keep temperatures constant. I have done lots of research. The only single skin wall I had to insulate were the 6inch thick ones. The 1 foot stone ones are fine.

Same with brick, but only IF: they are dry (look at the deep eaves on older houses). However the buffering works both ways:...

Also they may be more efficient than you think, but.... that's not very efficient in modern terms.

I can find my 2" celotex room in the morning at 5 deg or so, and have it at 20 deg. in ten minutes with a 1.2 kW heater (and if it wasn't full of cold stuff it would be much quicker). Once warm my body heat while working at the computer keeps it that way. You can't do that in a stone room.

 

[Beesnaturally]

Yes. I suppose we could get the beams sealed off with a false ceiling. The windows fill the whole window recess so adding insulation would mean we wouldn’t be able to open them. So no I won’t.

Quite. Its not that it can't be done, its that you don't want to do it.

btw insulating between beams goes most of the way as beams are good insulation themselves.

 

[madasafish]

Why? About what?

Do you think the bods in charge of upgrading the national grid, the folks who have announced 6 new large nuclear power stations, the investment community et al.. have all forgotten to model future demand?

Yes, decarbonising the energy supply requires a huge increase in renewable generation. Its a huge task. It will involve lowering demand in buildings. And it will involve home generation and intelligent metering. All this stuff has been studied and planned at the highest level, and in the investment communities, for decades. By people who are good at sums.

Spherical objects.
Such faith in people proven to be wrong. Or lying. And both.

Who closed down 70% of UK gas storage in 2017 as a cost saving measure? And have been forced to reopen it again?
Who decided not to invest in nuclear power for two decades when it was bleeding obvious to a child we needed to replace our ancient failing nuclear reactors?
Who publicly stated the nuclear power was dirt cheap and would solve all our energy needs for the future?
Who publicly stated (in 2020) we had enough electrical generating capacity to prevent blackouts in the future?
Who said Smart Meters would never be used to cut off consumer's supplies?
Who said we would invest in a fleet of small nuclear reactors in 2021 and would order a prototype to be operational in 2030.. and no order has yet been placed, nor is likely to be placed?
Who set up a system of energy supply that encouraged risk taking , unsustainable business models with the inevitable result of large scale failures and a LARGE increase in consumer bills to pay for the debacle?

ANSWER:
People who are "good at sums". People at "the highest level". People in "the Investment Community".

 

[Beesnaturally]

Spherical objects.
Such faith in people proven to be wrong. Or lying. And both.

Who closed down 70% of UK gas storage in 2017 as a cost saving measure? And have been forced to reopen it again?
Who decided not to invest in nuclear power for two decades when it was bleeding obvious to a child we needed to replace our ancient failing nuclear reactors?
Who publicly stated the nuclear power was dirt cheap and would solve all our energy needs for the future?
Who publicly stated (in 2020) we had enough electrical generating capacity to prevent blackouts in the future?
Who said Smart Meters would never be used to cut off consumer's supplies?
Who said we would invest in a fleet of small nuclear reactors in 2021 and would order a prototype to be operational in 2030.. and no order has yet been placed, nor is likely to be placed?
Who set up a system of energy supply that encouraged risk taking , unsustainable business models with the inevitable result of large scale failures and a LARGE increase in consumer bills to pay for the debacle?

ANSWER:
People who are "good at sums". People at "the highest level". People in "the Investment Community".

Hindsight is a wonderful thing.

Yes, politicians could have done a lot better. The science and specialist communities told them what they needed to do. Thankfully wind generation got under way, the national grid got strengthened and digitalised, 6 new nuclear power stations are on order, and the James Webb telescope is beaming us images form close to the birth of the Universe.

They can't all be idiots you see?

The real idiots are the public who elect the wrong politicians. The rest works pretty well.

 

[user 20297]

Let me just take the opinion out and mess it about so we can try to read it without the judgement.


This seems to hinge on the idea of equality of access, funded at state level, yes? Its anti-socialist? Its saying: if you can't pay the going rate (shoved up by people who can pay, that's ok?

And then: what is worse, this socialism is predicated on and justified by... a merely theoretical problem - ie man-made global heating.

And this idea: that we pay taxes to help poor people with their electricity bills (which are made higher by the subsidy of renewables) in pursuit of what could well be a phony goal (Net zero) ... is not something I agree with...

Is that right?

It's not Socialist to think that it's unfair to place a financial levy on all holders of domestic fuel bill accounts in order to give that cash in huge chunks to already wealthier individuals.
Taking issue with the way that the Government is tackling global warming does not imply a complete denial of the problem.
If we all end up with an improved outlook as regards control of the worsening climate and a small minority of people enjoy both the improved outlook and a significant financial benefit, my view is that the Government has managed the situation very badly.

 

[Beesnaturally]

It's not Socialist to think that it's unfair to place a financial levy on all holders of domestic fuel bill accounts in order to give that cash in huge chunks to already wealthier individuals.

I hope I didn't say it was. I think most people would agree its undesirable that the less well-off would have to pay it. There is near universal distaste at the levels of profit being made via the war windfall - but that's of late: I think you are talking about the renewables (green) levies on electricity prices. If so, I think its fine that most people pay higher costs for greater use (not just a higher standing charge), to provide the seedcorn money (which is what it effectively is) that draws in investors in renewable generation. Don't forget the treasury makes a huge profit from the offshore licences. Most people don't realise what an incredible success the public-private partnership that is offshore wind is. The green levies have made that possible - the gov can't simply borrow more or magic money every time it needs to make things happen.

Taking issue with the way that the Government is tackling global warming does not imply a complete denial of the problem.

I'm glad to hear that

If we all end up with an improved outlook as regards control of the worsening climate and a small minority of people enjoy both the improved outlook and a significant financial benefit, my view is that the Government has managed the situation very badly.

Capitalism always has winners and losers, and its the job of government to navigate a way to greatest social benefit; to protect the poor while engaging the better off to put their money to good social use. On the whole I think they all try to do that - though the parties have different ideas about how to go about it. Don't forget most investment comes from the like of pension funds.

 

[Erichalfbee]

Quite. Its not that it can't be done, its that you don't want to do it.

I can’t afford to.

 

[Beesnaturally]

I can’t afford to.

That's because you are paying a fortune for energy

 

[Erichalfbee]

You don’t know my circumstances. So best not assume.

 

[madasafish]

Hindsight is a wonderful thing.

Yes, politicians could have done a lot better. The science and specialist communities told them what they needed to do. Thankfully wind generation got under way, the national grid got strengthened and digitalised, 6 new nuclear power stations are on order, and the James Webb telescope is beaming us images form close to the birth of the Universe.

They can't all be idiots you see?
2.7GH
The real idiots are the public who elect the wrong politicians. The rest works pretty well.

Both political parties are to blame. And as a qualified scientist , it has been obvious for the last decade that it is all going wrong/

Wind generation is great when the wind blows: It is intermittent so a base load is needed.. Like a 100% backup. Or mass electricity storage. We have neither. Neither planned nor on order nor technically feasible in the volumes and capacity required.

As I write windpower is generating 2.7GW .Total demand is over 35GW. Anyone planning on windpower is planning for blackouts when gas power stations are closed.
(All figures from Gridwatch)

 

[Beesnaturally]

Both political parties are to blame. And as a qualified scientist , it has been obvious for the last decade that it is all going wrong/

Wind generation is great when the wind blows: It is intermittent so a base load is needed.. Like a 100% backup. Or mass electricity storage. We have neither. Neither planned nor on order nor technically feasible in the volumes and capacity required.

As I write windpower is generating 2.7GW .Total demand is over 35GW. Anyone planning on windpower is planning for blackouts when gas power stations are closed.
(All figures from Gridwatch)

The last Labour government put in place the legal arrangements for massive offshore wind. National Grid responded with a huge upgrade. They wrote sustainable policies deep into the heart of planning law.

The tories have carried on those policies - with the exception of loosening the requirements on new build insulation - thankfully, and to their credit, they've largely built on them.

As a scientist (que field?) I'd have thought you'd have figured out by now that every gW produce by renewables is a gW that doesn't have to be produced by fossil fuels. ...

Distributed generation: the wind is always blowing somewhere and we have new interconnectors exchanging electrical power right across the continent. They'll probably be attached to vast North African solar farms before long.

Yes, we need standby: that'll be home batteries and cars, stored hydrogen, industrial-scale battery banks and about 10 nuclear power stations. And doubtless the odd gas plant, perhaps maintenance of biofuel generation.

There are oodles of things we can do to fill in the cracks. Insulate buildings mostly.

I mentioned the James Webb telescope early. Technological miracles like that happen because there are competent grown up in charge. Why people assume that's not the case in the UK I don't know.

The main issues are about timing, not about the need, nor the possibility. Its even beginning to sink in that this presents huge opportunities for us.

The main obstacle (it is also starting to sink in) is oil money, going to lobbying and disinformation. And public ignorance and lack of concern. I'm all right (now) Jack.

 

[Sutty]

Just for the record solid stone thick walls are far more efficient than you give them credit for. They act as thermal stores in their own right and once warm will help keep temperatures constant. I have done lots of research. The only single skin wall I had to insulate were the 6inch thick ones. The 1 foot stone ones are fine.

A quick Google (which I did recently when adding a layer of insulation inside a thin stone wall which had a condensation problem) reveals the R-value of stone as 0.08 Vs an R-value for polyurethane board of 6.25 (imperial units).
This means that a 2 foot thick stone wall has the same insulation properties of 0.3 inches (about 8mm) of polyurethane board - so I can't agree stone is "more efficient than you give them credit for"!
On the plus side it means if you can add internal insulation you don't need much to double the insulation properties!

 

[enrico]

A quick Google (which I did recently when adding a layer of insulation inside a thin stone wall which had a condensation problem) reveals the R-value of stone as 0.08 Vs an R-value for polyurethane board of 6.25 (imperial units).
This means that a 2 foot thick stone wall has the same insulation properties of 0.3 inches (about 8mm) of polyurethane board - so I can't agree stone is "more efficient than you give them credit for"!
On the plus side it means if you can add internal insulation you don't need much to double the insulation properties!

Who am I to argue? My only question would be how long does the polyurethane board retain the heat once warmed compared to a foot thick stone wall.....that was my point!