JamesPa

Its the Daily Telegraph!

Here are the regs for BUS https://www.legislation.gov.uk/uksi/2022/565/contents/made Reg 9(2) requires that the heat is delivered by a liquid. Based on your explanation of A2A above I think that excludes A2W but there clearly may be room for debate. Definitely there is no exclusion of units capable of cooling as some maintain there is. However pd rules don't apply if used for cooling, which is a separate consideration to the grant.

Thanks for the clarification. I think you are right that the legal system can't deal with the finer points of thermodynamics but on that account I would say the delivery medium is a gas. It would be interesting to understand what the intent was. If it's only to allow a2W why use 'liquid' as opposed to 'water ( which may be treated to prevent corrosion or freezing)'

The word used in the regulations is 'liquid'. I can't see how refrigerant once compressed doesn't meet this definition and my understanding is liquid when it hits the heat exchanger.

That's an interesting question. The regs say that heat must be delivered 'by a liquid'. For some reason it doesn't say 'delivered by water'. So an A2A system that heats the house and dhw via a liquid refrigerant may qualify. My understanding is that the refrigerant is liquid at the point it hits the heat exchanger in an A2A system. It also needs to heat the dhw which is entirely possible but not normal, but perhaps it could be.

That's exactly my understanding too. Of course that doesn't prevent you claiming bus, installing under pd, and then making a planning application to use the already installed unit for cooling. Obviously you wouldn't do this if your principal reason for install is cooling, but if that's the secondary reason you just might.

I can't find anywhere in the bus rules where it actually says this. I think (but may be wrong) that this is a common myth based on a misunderstanding of the permitted development rules (which do not apply to ashps used for cooling, but don't actually prohibit ashps capable of cooling) If someone can point out in the bus legislation (link above) where it prohibits cooling I am happy to be proved wrong.

Is this actually the case. I can't find it in the bus rules https://www.legislation.gov.uk/uksi/2022/565/contents/made but maybe I missed something. Permitted development excludes the use of an ashp for cooling, but doesn't exclude ones which are capable of cooling

Personally Id rather discuss, in a constructive way, solutions to problems we collectively face. Unfortunately there appears to be a tendency in this thread to dismiss any positive suggestions made by those commenting, or by those in power, but without (in most cases) providing practical alternatives which we could debate. Ultimately this gets us all absolutely nowhere, but I guess serves as a vent for frustration. As you say this is thread drift. We could start another thread entitled 'No hope' or 'Vent your frustrations' which those who wish could follow. We could also start one entitled 'Petition to repeal the second law of thermodynamics' whilst we are at it. The title of this thread is Are we targeting ASHP's at the wrong market.

Yeah, but now it's hailed as a great success. If you build your own house, chances are it will go over time and over budget. That's the nature of construction unfortunately. Government isn't magically immune to the failings that afflict us as individuals and, unlike individuals, has to deal with changing colour potentially every 5 years, which is a lot less than the timescale for major infrastructure projects. This alone inevitably multiplies cost. I'm not defending it, but don't have a practical alternative proposition if we are to build national infrastructure. It's easy to criticise, but what is the alternative?

Haven't heard many complaints about the Elizabeth line. The point surely is that part of the role of a successful government is to take risks that the private sector won't, in the greater interest of the nation. So you can expect them to be difficult, controversial, and occasionally even to fail at least in part. Unfortunately it doesn't suit the media narrative of perpetual incompetence of government to point that out, because in reality all they want is to swipe at one side of the political divide and a sup to the other, in support of their paymasters. I'm not defending HS2 btw, imho it's an anachronistic vanity project promoted by the rail industry, suited to an age before it was possible to work whilst on train, and a country much bigger physically than the UK.. Unfortunately government fell for it, but now we have to make the best of it. Such projects often find a good use eventually! If someone desires a society run solely by the oligarchy for the oligarchy then so be it. Just bear in mind that this is the ultimate objective of the drip drip of bile in certain sections of the media. Unless someone following the lead of this sector of the media is very rich, they are almost certainly acting against their own self interests. Since the majority aren't very rich, this shouldn't be a threat. Unfortunately, time and time, again turkeys do vote for Christmas (or for that matter Thanksgiving) lured into that by the misinformation put out by those parts of the media.

As a variant of this option - Buy the baseload at one price (guaranteed contract, you pay even if you dont consume and supplier pays the difference if they cant supply) and the variable load at another price. Re "Providing energy at competitive rates would be a major economic boon to the UK. " My crude understanding is that our model for computing electricity prices (and in particular the fact that its based on the marginal price, ie the price for electricity generated from gas) is driven by the EU. This begs the question - how did we end up with more or less the worst ratio of gas to electricity prices in the EU. Was the previous government (or the government before that) asleep at the wheel?

Difficult one then. Investment needs incentives and so we have to expect some profit to go to those investing. The question is whether it's excessive or not. I don't have the facts.

Where does the 'excess' go I wonder. Is it making electricity generation ultra profitable for those who generate (at scale) using renewables, or is it offsetting something else?

Sometimes good and practical ideas come from off the wall thinking!

I will assume that was intended to be facetious!

Based on my experience so far I would say one useful option is to switch on an electric resistance heater during recovery from defrost. Rare and for a short period of time so cost not particularly significant. In my own case I'd only do it at night as principally it's to reduce noise, at negligible cost because my night time tarrif is low. We need to be careful not to rule out options to manage things in the myriad of house configurations we have. A one size fits all approach will make the transition more difficult.

In 99% of households this just isn't required, just heat the water to 50, it's no longer an issue anyway. Most houses run on chlorinated water (like or not), if you have an unvented system also, how does legionella get in? I agree you are probably right, but that's not the point. The point is that, until there is a public health statement from the NHS to the contrary, legionella protection will inevitably be fitted/required by some, if only for liability reasons and so until we fix that it must be provided for. If there were an authoritative public health statement that could change, but it can't change based on your opinion or mine, it needs someone with the relevant qualifications in the relevant position. Is that a real comment, add in loads of defrosts at anything approaching zero, sounds like a good system performance will prevail - NOT. I said it's not ideal, but the world isn't ideal and to outlaw it is going too far. There are people who quite happily run at this temperature accepting the cost trade off and it's still better for the environment than burning fossil fuel. Not everyone lives in a well insulated new build with lots of space and money for large radiators, and if we want to get to 1.4m per year we need some flexibility for people to make informed trade offs.

I just said a way Well yes but...its hardly making it easy in the scenario where your gas boiler breaks, you are banned from buying a new one, and the industry takes weeks to give you a poor quote for a replacement ASHP for which you might yet need planning permission. We do have to try a bit harder than just legislating against things if we are to take the public with us! So a new gas appliance has the same playing field as a heat pump. I would apply those limits to ALL heat pumps also. R290 can pump out 70+ degs, but at a CoP hit so why allow it. I thing the principle is a good one (and building regulations aren't that far off now) but honestly whats wrong with 55? Its not optimal for sure, but still gives a COP of 2.5 and probably tolerably sized radiators whereas insisting on 45 quite likely makes it impossible and totally impractical in some cases. Also my heat pump does the legionella cycle at 70. Obviously the COP is rubbish, but better than the immersion heater. I grant that the need for a legionella cycle is questionable, but while many still view it as necessary and in the absence of a proper public health statement on the matter any law must provide for it.

We replace ~1.4M gas boilers every year, presumably mostly because they are beyond their useful life. Thats 1.4M (missed) opportunities to fit an ASHP at a time when the homeowners are anyway chucking out their existing heating. The challenge is presumably that many of these are distress purchases. Somehow we need to find a way to fit ASHPs in these cases as well as the cases where there is more time.

Whilst I fully sympathise with your views and would probably do this if I could, I fear that the headlines in certain parts of the press would make this politically impossible. Just look at the confected fuss over LTNs! That said you can do a lot of unpopular things near the beginning of a term of office!

Sorry to ask again, but what would you do differently (within the bounds of political reality and physics)?

Unfortunately the newspapers (and other media) create, at least in part by pedalling deliberate misinformation or analysis so dumbed down as to be laughable, the environment in which the politicians have to operate to win votes. If we didn't have such a divisive political system it might just be possible for the more sensible politicians to get together and overcome this, but we do have a divisive political system. Noted and of course that is your prerogative. (Would a modest decline in return for greater security such a bad thing - is monetary wealth the sole goal of the human race, and is it compatible with the laws of nature?)

Thanks. I don't have ebusd or another way to graph compressor modulation unfortunately. I can graph many parameters using ha, but not this one. So I'm reliant on the MK1 eyeball method. I will keep monitoring.

So no solution then, just give up hope and you might as well do nothing. How depressing! PS why should we expect the problem to be fixed in a 5 year timescale, as you say thats unrealistic. Is it solely because we, as a nation, are too stupid and too much led by the Daily Mail (other organs of information and misinformation are available) to realise that some things take longer than a single electoral cycle?