Posted by: @jamespa

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I guess we have to comfort ourselves that we have chosen to be early adopters, so can expect this sort of nonsense.

I agree, and constantly remind myself of this. I am still the only one I know of in my locality who has a heat pump. I even said to one of my local councillors at one point when it all seemed like it was going to fall apart that if I, a capable and enthusiastic early adopter had to fight so damned hard to get it to happen, then what hope was there that Joe Blogs would apply the same determination? She didn't really have a reply, and to some, possibly a large, extent, that is the problem, an inability to see that if you put hurdles (I use the term widely, to mean anything obstructive) in the way, then people start giving up. There is also a serious lack of imaginative drive, a lack of how can we make this happen? And, as has always been the case, the career politicians are, well, just that, career politicians, without the necessary background to understand more technical matters. Whether there was ever a golden era when permanent civil servants did have some expertise I am not sure. It may always have been 'Yes Minister' behind the scenes as much as it ever was on TV.

@cathoderay Yes indeed, early adopters (even if it is of of well established engineering mechanics) we are, and I suspect, most if not all of us by conviction to ‘go green’. I also think it may well have cost us dearly to stick to these convictions to not use ‘cheap’ gas for our heating.

One thing that seems sorely lacking from any governmental department is any attempt to tackle the ‘Spark Gap’ This ludicrous situation where any use of gas dictates the wholesale price of electricity regardless of the means by which it is produced is in the word of Greg Jackson ‘Bonkers’!

Surely the best way of securing a speedier adoption of Heat Pumps would be the carrot not the stick - make it cheaper to heat with ‘leccy’ than gas. Persuasion via the wallet or purse is far more headline grabbing for the passenger on the High Holborn bus! Regrets, Toodles.

Posted by: @cathoderay

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... the career politicians are, well, just that, career politicians, without the necessary background to understand more technical matters. Whether there was ever a golden era when permanent civil servants did have some expertise I am not sure. It may always have been 'Yes Minister' behind the scenes as much as it ever was on TV.

I have just picked up this point in a part of the Forum only available to Moderators.

Apologies to @toodles and others, but there's some sensitive information therein.

Within that private topic I've illustrated an issue which is too technically deep for politicians to be expected to respond to,
but I've shown how an MP is able to pick up such a matter and 'require a response from the Minister'.

Whilst the subject matter is different, I think @cathoderay has now reached that point with his Midea ASHP.

He's got enough detail to demonstrate that the regulatory bodies (and MCS in particular) are pursuing strategies which are deficient and not based on the underlying science.

That can be written up as a 'Briefing' to his MP.
The accompanying letter/email makes the points

• that the Government can't achieve Net Zero if decisions aren't supported by the required physics
• that  ASHPs is a vital part of the Net Zero policy
• that the take up of heat pumps under the Boiler Upgrade Scheme falls far short of Government targets (provide a graph like the one below, but with the latest plots included)
• that take up is adversely affected by poor customer experience

The MP doesn't need to understand the Briefing itself.
They read those bullet points and appreciate the significance of the matter being raised.

The MP forwards that email and Briefing to the relevant Minister.

Posted by: @toodles

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Persuasion via the wallet or purse is far more headline grabbing for the passenger on the High Holborn bus!

I absolutely agree. Not only is it absurd that electricity costs so much more than gas per kWh, it is even more absurd that way pay extra levies* to go green. The pricing needs to be such that it removes the gas is cheaper to run argument. I also think bigger installation grants would go a long way towards increasing uptake. It might cost more to government upfront, but there are rewards later on. Bigger grants might also be a vote winner! 

These levies are typically hidden behind obfuscation. Ofgem don't even call them levies, they are instead 'policy costs'. It also likes to hide the electricity levy by mixing it in with gas, and giving figures for dual use punters. I think, so far as I can tell, the levy currently accounts for around 15% of a typical electricity bill, but only 5% of a typical gas bill (@transparent may well have better and or more recent figures). It needs to be the other way round! Or, if not that, then the same for both fuels. 

Posted by: @transparent

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That can be written up as a 'Briefing' to his MP.

I sense a call to action! However, the resolution of my heat pump woes is very much a live matter at the moment, as (hopefully) both my installer and Freedom both come out of their Christmas breaks this coming week. I have also not yet approached MCS, partly because I don't think I have necessarily got as far as I can go with Freedom and my installer yet, and partly because I am not a great fan of playing message in a bottle games (even if at some point I may have to).

Posted by: @transparent

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The MP doesn't need to understand the Briefing itself.
They read those bullet points and appreciate the significance of the matter being raised.

As a former local government employee (following a career in engineering) I realised that explaining the consequences to politicians simply and in terms they could understand was key to good decision making.  Fortunately the company for which I previously worked had a PowerPoint based metabolism, and I found this invaluable in simplifying situations down to the key material options.

From my perspective 'Yes Minister' (which may well be accurate) was an amusing but unfortunate representation of political decision making.  The job of the civil servant at any level is to make sure political decisions are based on as accurate an understanding of the consequences as humanely possible, without interfering in genuinely political choices*. 

I was always clear that genuinely political decisions should be made (and the consequences shouldered) by politicians, and on many occasions I declined to make any recommendation in respect of a course of action for this very reason.  On other occasions (probably most) it was objectively clear what should be done (or should be done if declared political objectives are to be achieved) and in those circumstances I was very clear what decision the politicians needed to make and, if necessary, I would refer back to their declared objectives in making such recommendations. 

Looking back the approach rarely failed. On occasions of course the councillors made decisions with which I disagreed, but almost always for genuinely political reasons in full knowledge of the consequences.  That's perfectly ok, its called democracy!

MPs and local politicians are the same type of people so far as I can tell (many MPs start off as local politicians).  Obviously the more senior MPs are either more determined or more ruthless (or both), but in essence I believe they (mostly) start from similar places.

However presenting simplified consequences and getting them appreciated successfully requires a degree of influence, either because of position (which the industry has) or out of trust.  The issue for me is that I can't find a way for people who understand the matters in question, but do not have a vested interest, to get a trusted voice.

So, at least based on my own experience, I think @transparent is right, but the key question is how to get a voice given that the industry will see (so far as I can tell  already sees) knowledgeable or simply intelligent outsiders as a threat.

To that I have no answer, but I am convinced that, if we could overcome this problem, we could make a genuine difference.

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*To be clear, there is imho, absolutely nothing political about, for example, the science of climate change.  The political question is the response to the facts.  IMHO its entirely legitimate politically to say 'do nothing' so long as one doesn't try to justify the position or delude others by either denying the science or the spectrum of possible societal consequences.

Posted by: @jamespa

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an amusing but unfortunate representation of political decision making.

It wasn't meant to be a representation of political decision making, just as Fawlty Towers wasn't meant to be a representation of a small town hotel! Both used the classic situation comedy wheeze of placing an individual in a situation that was a bit beyond them, and then letting rip.

One of the all time greats in my view, starting at 2:50

cathodeRay KCMG 

I have been looking a bit more closely at what actually happens when my heat pump gets itself into can't quite cope mode, and the IAT falls, ie when the OAT is around zero or below for several hours or more, and comparing it to a time when the OAT is warmer: 

One thing I hadn't really noticed, or rather hadn't paid too much attention to, is the relation between actaul LWT and set LWT changes. In normal running, with 'normal' cycling, the actual LWT routinely overshoots and then undershoots the set LWT, with a result that the effective (mean) LWT is about where is should be (the same as the set LWT). However, when the OAT is at zero or below, and the heat pump is going flat out and using defrost cycles, the actual LWT is mostly only ever at or below the set LWT, ie there is no overshoot, or if there is, it is small and short lived. As a result, the effective (mean) LWT is considerably less than it needs to be.

The above chart is the result of my current WCC/auto-adapt settings. These are currently set up very cautiously at the low OAT end to ensure that the heat pump doesn't try to exceed its capabilities ie take the LWT over 60 degrees, with possibly deleterious consequences for the local environment. However, looking at that chart, I think I might be able to tweak the WCC/auto adapt script settings to allow the LWT at zero or below OATs to go a degree or two higher. This will need a very careful eye on things, plus a hard cap at say set LWT of 59 degrees, to ensure the heat pump doesn't go outside its operating range. It looks like we are in for another spell of cold weather over the next couple of days and that should provide a chance to try running the heat pump a little bit hotter, to see what happens. If I can squeeze a bit more heat out of the heat pump without putting it in mortal danger, then it just might solve the can't quite cope at low OATs problem. I will report back in due course.     

@cathoderay  - I'm about to email a technical member of a Government Committee which is tasked with developing the forthcoming protocols for remote control of heat-pumps (and other Energy Smart Appliances), known as Demand Side Response. I'll be referring to this topic.

A: Can you please clarify for us how much you're inclined to believe there is a 'deficiency' or 'mistake' in each of the following categories:

1. the Midea firmware, its WCC algorithm etc (as per the Title of this topic)
2. the OAT sensor accuracy, lag, hysteresis etc
3. the configuration of your system by the installer; the commissioning process or the system design/layout

Please evaluate each category separately, according to your current assessment and level of confidence.
The sum total can be more than 100% !

B: Please expand on what you mean by "the heat pump is going flat out and using defrost cycles..."

1. Does the defrost cycle take heat from the DHW cylinder, and does it also turn on the immersion heater?
2. Do you have glycol or other additive(s) in the system, and if so was the quantity stipulated by Midea, the installer or yourself?
3. Do you have anti-freeze valves fitted on the external pipes (I assume not, otherwise you'd be refilling the system each time it freezes!)

Many thanks.

Posted by: @transparent

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• Does the defrost cycle take heat from the DHW cylinder, and does it also turn on the immersion heater?

 

This is an interesting one which had faintly crossed my mind.  Does any heat pump do this. 

I have heard that there are some which have an auxiliary electric heater for defrost, but this approach would remove the need for a separate auxiliary, which would mean that the method could be selected or not (by the heat pump controlled) depending on the excess capacity available but without having unnecessary components.  That said an electric heater is pretty cheap!

@transparent - certainly, here are my replies:

A: at the moment it is 50:50 between 1 and 3, with 2 not really part of the problem (because the WCC can take account of things like the 'OAT' being in fact the air intake temperature). The focus in option 1 is on modulation, either a hardware or software fault, such that modulation doesn't happen when it should, though I have since discovered there is a small amount modulation, the question is whether this limited restricted modulation is by design of by fault, and only Freedom can answer that question. The focus in option 3 is on the pipework, is it too narrow, and therefore restrictive (limits flow)? The jury is still out on this, which is why, taking all together, I have to say it is 50:50 between options 1 and 3 (or even a bit of both). We need Freedom's input to get to a clearer position. You might want to mention the problem of uncommunicative and unhelpful suppliers in your email, it has been a major problem in my case.

All the above said, I have in the last 24 hours realised there may be a tiny bit of headroom left in my system at the low OAT end of the weather curve, see my immediate last post above. If that can supply the deficit, then it will be a lot easier than fixing modulation and/or structural alterations.

I'm sorry I don't have a definitive answer yet, it is the nature of these things that they evolve over time, a time span largely governed by what the weather actually does, because we need the real world data of what actually happens in different conditions.

B:1 I don't think the defrosts take anything materially from the DHW, as the two way three port valve is always set to space heating, apart from during timed DHW heating (between 1300 and 1400) and very occasional manual DHW heating. The vast majority of the time the heat for defrosts comes from the house. I do have a DHW tank immersion heater fitted, but it is not in use.

B:2 I do have glycol in the system, at a quantity set and supplied by my installer. I don't know the exact percentage, but I do know that at my last annual service a fem months ago, my installer said (based on a refractometer reading) the current level of protection is down to -8 degrees C.

B:3 You are right, no anti freeze valves (and no plans to fit them).

Hope that helps, don't hesitate to ask if you would like more information.       

Posted by: @cathoderay

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One thing I hadn't really noticed, or rather hadn't paid too much attention to, is the relation between actaul LWT and set LWT changes. In normal running, with 'normal' cycling, the actual LWT routinely overshoots and then undershoots the set LWT, with a result that the effective (mean) LWT is about where is should be (the same as the set LWT). However, when the OAT is at zero or below, and the heat pump is going flat out and using defrost cycles, the actual LWT is mostly only ever at or below the set LWT, ie there is no overshoot, or if there is, it is small and short lived. As a result, the effective (mean) LWT is considerably less than it needs to be.

Interesting. 

I currently run in 'low noise' mode at night and I find that mine overshoots in both 'normal' cycling and defrost but not when 'low noise' mode is active.  These subtleties of behaviour have the potential to matter quite a lot.

Posted by: @jamespa

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These subtleties of behaviour have the potential to matter quite a lot.

I agree, and it is why we need to look so closely at actual behaviour. 

I have just upped each end of the WCC by one degree, it is now 57 at -4, 35 at 15. I will report back on what happens once it has been cold for a while.