Lots of hot air

[Jacob]

....

I don't subscribe to a nanny state mandating personal choices and behaviours. A tax and regulatory framework which ensures those who choose to enjoy (selfish) freedoms pay for the pleasure is a better solution. .......

What's the difference?
The nanny state protects people from the unscrupulous; should the owner of a ship be free to make a personal choice about the number of lifeboats?
Also protects people from their own weakness, poor judgement, whatever.
"Nanny state" is just a right wing cliche about reducing public spending and regulation, part of the imaginary "culture war".

 

[John Brown]

don't understand why air source heat pumps cannot be used across most of the UK - they don't need extra land, work to high levels of efficiency to both warm and cool, and can be installed in the average house at a cost not dissimilar to the average gas CH system.

As I understand things, they are a lot more expensive to buy and install, and they don't heat the CH water to a high enough temperature to work with existing natural gas fired radiator systems.
I don't really understand why they should be more expensive, and I know the govt. are planning to reintroduce some sort of grant, but the sceptic in my soul suspects that grants and scrappage schemes tend to benefit the suppliers and installers, rather than the homeowners.

 

[TominDales]

As I understand things, they are a lot more expensive to buy and install, and they don't heat the CH water to a high enough temperature to work with existing natural gas fired radiator systems.
I don't really understand why they should be more expensive, and I know the govt. are planning to reintroduce some sort of grant, but the sceptic in my soul suspects that grants and scrappage schemes tend to benefit the suppliers and installers, rather than the homeowners.

I agree. I dont understand why they are currently so expensive. They are quite common and a lot cheaper in Germany.. That may be the thing, they are still an artisan specialist appliance in the UK and we need mass market innovation to crash the price.
Like you I'm sceptically of grants, except to get a new new markets going where the initial supply chain costs and market start up costs inhibit trade against incumbent technology.

 

[Spectric]

"Net zero" means that greenhouse gas emissions produced equal those removed from the atmosphere. It is not "zero emissions" - it no doubt gives the government some wriggle room.

That will not be much use in getting global warming under control, all that says is that we will only put into the atmosphere an amount that has been offset somewhere else so it will still rise under it's own momentum.

The failure to mandate better building standards is evidence of the influence property developers have over government policy. The government should govern. We will live with the consequences for 50-100 years. Much better to include in the original build than retrofit.

Property developers have most local councils in their pockets and have a blatant disregard for the enviroment, impact on peoples lives or the rat race they leave behind, for them it is only the money to maintain there desire for wealth.

The nanny state protects people from the unscrupulous;

It also protects them from themselves.

I know the govt. are planning to reintroduce some sort of grant,

How many of these government grants have ever really delivered, often a bribe to make householders do something they otherwise would not and in some cases have actually cost them a lot more to put things right. The real solution is to rein in the property developers, provide a new set of building regulations and make all new housing suitable for the future, ok they will get fewer properties onto a given area of land but they have had it to easy for too long.

 

[Spectric]

Heat pumps are one of those things that are much better in theory than often in practice. In essence they are trying to get you free heat, the system itself generates no heat by consuming a source of fuel like gas but does consume energy. Best way to think of them is like a refrigeration system working in reverse, which itself is based upon the principles of change of states of the refrigerant. So ideally they move any available heat from outside your house inside to warm water for circulation, my issue here is that when you need most heat it is at it's coldest outside so now they must rely more on the heat produced by the compressor so in my opinion this is not efficient.

 

[Rorschach]

Heat pumps are one of those things that are much better in theory than often in practice. In essence they are trying to get you free heat, the system itself generates no heat by consuming a source of fuel like gas but does consume energy. Best way to think of them is like a refrigeration system working in reverse, which itself is based upon the principles of change of states of the refrigerant. So ideally they move any available heat from outside your house inside to warm water for circulation, my issue here is that when you need most heat it is at it's coldest outside so now they must rely more on the heat produced by the compressor so in my opinion this is not efficient.

You sound like a real expert there.

 

[Spectric]

No expert in the ground source heat pumps for homes but have worked on industrial refrigeration systems and heating systems with a good background in physics so you get to know when claims look a bit stretched, I suspect they work better when you live in a milder climate and just want to take the chill out of the air.

 

[Rorschach]

No expert in the ground source heat pumps for homes but have worked on industrial refrigeration systems and heating systems with a good background in physics so you get to know when claims look a bit stretched, I suspect they work better when you live in a milder climate and just want to take the chill out of the air.

You really have very little idea what you are talking about.

 

[hairy]

The air source heat pump we had was of course the big box outside, plus inside was a cupboard about 900x900 floor to ceiling with about half being the hot water tank and half the control system. That was adjustable only via engineer laptop other than the simple bits, and I can quite appreciate that all being a lot of cash. Plus floor slab with pipework, manifolds etc during build performing better (but still a bit rubbish and not cheap to run) than the oversized radiators required for fitting in an older house. My current neighbours' pump apparently was not specified with a parts suitable for being closeish to the sea which would have been another £100 originally, but after five or so years the lot needs replacing at £16,000. In that case, and was evident with the plumber installing ours and the manufacturer engineer who also had to repeatedly come out, there may not be much expertise with these in the UK yet?

 

[Spectric]

You really have very little idea what you are talking about.

What don't you understand, I tried to keep it simple as making things over complicated is not the best way to explain the basics.

 

[Rorschach]

What don't you understand, I tried to keep it simple as making things over complicated is not the best way to explain the basics.

Well if that was your goal you introduced a lot of confusion as well as stating things that are just plain wrong such as relying on the compressor for heating

 

[Spectric]

Well if that was your goal you introduced a lot of confusion as well as stating things that are just plain wrong such as relying on the compressor for heating

Ok I assumed a very basic level of physics, obviously assumed wrong. Most people understand that when compressing a gas heat is produced, think back to when you pumped up your bike tyres and the bicycle pump got hot. The same with turbochargers and using an intercooler to reduce the charge temperature and the diesel engine relies on the heat produced through compression to initiate combustion. With heat pumps the liquid is turned to gas as it is warmed by the outside air, then compressed to increase the pressure which adds heat. These gases pass through a heat exchanger to transfer the heat into the water, in doing so they condense back to a cool liquid to repeat the cycle again.

 

[Terry - Somerset]

I have but a very limited understanding of real physics.

But I gather the typical aircon unit can either blow cold or hot air using the phenomenon of a heat exchanger and compression/decompression of the refrigerant gas.

Most literature refers to an efficiency of 3-400% for modern units. I take this to mean that for every kw of energy used to compress and criculate gases, you get ~4kw out. Used directly for heating a 1kw bar fire produces 1kw of heat - hence the efficiency.

I also understand that efficiency falls at lower temperatures. I suspect manufacturers literature is somewhat optimistic they suggest cold weather performance effective down to -xxC.

Therefore they may not be the right solution for north Cumberia and the Highlands - but for namby pamby southerners south of Brum they may be just the ticket!

 

[Doug71]

Plenty of hot air coming off Roger Bisby telling us about heat pumps.

 

[Spectric]

I am sure that guy was a builder comparing tracksaws not long ago, probably started of selling double glazing!

 

[Woody2Shoes]

Its all in Gods hand. Those that can see it can see it for want of a better phrase. There is nothing us "highly intelligent" humans can do about it. We carry on thinking we can but when you really look into it, theres truly nothing we can do. Its a one way path and the end of it is not far away, what is in the book in Revelation is happening today.

Regardless of what you believe or dont believe, its becoming increasingly obvious nothing can be done about it as you say. Shoot me down those who will but I believe what I believe and wont change that for anything.

Personally, I don't believe in God (if I'm wrong, I'm told he is both supremely benevolent and omniscient, in which case he already knows about my mistake and forgives me for my silliness ). I don't think any of us can say with any certainty (I thought this was a woodworking forum, not a climate change experts forum, and even they don't know) whether or not it's too late to avert climate-geddon, but I do subscribe to the notion that when you're in a hole you should stop digging.

Anything any of us can do to reduce our individual and/or collective impact on the environment is very definitely worth doing (even if we're all doomed/damned).

 

[Woody2Shoes]

I am sure that guy was a builder comparing tracksaws not long ago, probably started of selling double glazing!

He's normally pretty sensible.

My 2d's-worth is that there's nuggets of truth in what he's saying:
- they are annoyingly noisy (I predict more neighbour disputes, similar to those between suburban [i.e. nearly all] Australians over pool-pump noise);
- they are least efficient, and likely to put heaviest loads on the electrity grid, when the air is coldest (whether or not they need to use energy to defrost themselves is another question);
- most installations will be in homes where there is insufficient insulation - "fabric first" is the (correct) mantra - and where good design in pushed out of the window by the desire to maximise profit (on the part of the installer) and/or minimise cost (on the part of the homeowner, who may genuinely not feel the need to take a long-term view).
- many homeowners will balk at the cost/disruption of installing proper insulation, ventilation and right-sizing radiators (to suit reduced flow/return temps).

I do wonder how many combi boilers spend their working hours in proper 'condensing' mode....

I foresee a cluster-flap, and don't get me started on 'blue hydrogen'......

 

[Rorschach]

The biggest issue I see with heat pumps for those on low incomes is that they need to run constantly in order to keep your hot water hot and your house warm.
My gas boiler runs when I want hot water and when I don't it uses zero gas. My heating runs when it gets unbearably cold (under 16C usually), otherwise it is using zero gas. I can't afford to just set the thermostat and leave it running all the time and that's with cheap gas now, imagine doing that with expensive electricity for both my heat and hot water.

 

[RobinBHM]

The biggest issue I see with heat pumps for those on low incomes is that they need to run constantly in order to keep your hot water hot and your house warm.
My gas boiler runs when I want hot water and when I don't it uses zero gas. My heating runs when it gets unbearably cold (under 16C usually), otherwise it is using zero gas. I can't afford to just set the thermostat and leave it running all the time and that's with cheap gas now, imagine doing that with expensive electricity for both my heat and hot water.

air heat source pumps are only suitable for houses with high insulation levels - probably to current building regs standards or passiv haus.
So not suitable for majority of UK housing stock.

how we get over the problem of this countries houses having poor insulation’s levels, I really don’t know. The govt won’t or can’t sort out the fire risk cladding, it’s got chance getting every house well insulated.

 

[John Brown]

https://www.theguardian.com/busines...to-use-electricity-transformers-to-heat-homesSaw this today.
I thought it was interesting, despite being in the commie Grauniad...