@jamespa

I have just Google'd 'Who funds MCS', and obtained the following comical message.

It is supported by the Department for Business, Energy & Industrial Strategy. Having an MCS Certified product installed by an MCS Certified Contractor means users can be confident that their system will perform efficiently and safely.1 Mar 2023

Posted by: @derek-m

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Whilst I agree that the present systems need vast improvement to encourage uptake of heat pumps, your idea of HT heat pumps I feel will have even bigger problems when people become aware of the running costs.

Installing better insulation and larger heat emitters may discourage some, but once done they will reap the benefits for years to come.

Your assessment of SCOP in your spreadsheet is far from real world situations. Below are some details of SCOP's that can be expected. The password for the file is midea2020

Thanks for this.  I can only see manufacturer data here not 'real world situations'.  Am I missing something? 

My analysis used manufacturer data (from LG not Midea) so, as far as I can determine, is on the same basis as the document you have very helpfully provided.  Another individual on another forum reported a real world SCOP of 3.0 (at 55 in the North of England) for an earlier LG model, against a predicted SCOP based on manufacturer data of 3.2, at least giving one point to suggest that manufacturer data is not actually so bad.  And remember a SCOP of 3 is good enough with the current ratio of gas prices to electric, which is artificially weighted in favour of gas and hopefully likely to change.

Your statement 'Installing better insulation and larger heat emitters may discourage some, but once done they will reap the benefits for years to come.' presumes that people have the capital funds to invest.  Most don't and are forced in many scenarios to trade long term cost for short term affordability.  If this weren't the case nobody would ever take out a loan or a mortgage.  We cannot keep (arguably somewhat arrogantly) asserting that short term pain for long term gain is the only way forward, many people just cant afford it.  The industry has to provide choice, not assume that everyone can, or wants, to do what they want or think is 'best'.

As it happens I think that installing bigger emitters is the least of the problems with the current 'throw it out and start again' approach, since emitter replacements are relatively cheap and easy in most cases.  Most quotes I hear about seem to involve replacing also the DHW tank, associated pipework and frequently other stuff too.  This is, if anything, more difficult to justify to the customer as it is unlikely to improve their experience materially and, even if it does, unlikely to be sufficient to convince them to pay the vast cost and suffer this disruption.  The upshot is inevitable that they don't change and either keep their existing fossil fuel boiler or replace it with a new fossil fuel boiler.  That may suit the installation industry, small volumes high price is a good business model, but it doesn't suit the planet.

I know I'm being a bit provocative, that's (as I admit above) deliberate.  But its also necessary if we are to get out of the current rut which leads inexorably to heat pumps remaining a minority interest in this country.  We need to think out of the box, think the unthinkable, until we find a sweeter spot than the one we are currently in.  I'm not saying I have the solution, but some thought around the proposal will, I'm pretty sure, get us to a better place than we are today.

@derek-m According to MCS accounts they are funded mostly by 'trading activity'.  More specifically:

According to its website MCS became a charitable foundation independent of Government in 2018, and decided to do so in 2015. its revenue comes almost exclusively from trading (Yellow = trading activities, Green = Investments)

And its its trading arm, MCS service company, states in its most recent accounts that 

So it appears that it is funded by the industry.  it may well be that BEIS 'support' MCS, but I seem to remember hearing somewhere that he who pays the piper calls the tune.

@jamespa

I was primarily referring to the comical part of the statement.

'Having an MCS Certified product installed by an MCS Certified Contractor means users can be confident that their system will perform efficiently and safely'.1 Mar 2023

Reading many of the posts on the forum, which I have been doing for the past couple of years, this is not always the case. What is that other saying 'the tail wagging the dog'?

Posted by: @jamespa

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...... presumes that people have the capital funds to invest.  Most don't and are forced in many scenarios to trade long term cost for short term affordability.  If this weren't the case nobody would ever take out a loan or a mortgage.  We cannot keep (arguably somewhat arrogantly) asserting that short term pain for long term gain is the only way forward, many people just cant afford it. 

totally agree with this. I recognise that I'm in a very fortunate position of having had the capital to invest to make the changes that I have done with my house, and that the vast majority don't have this option. we're all in the innovators to early adopters section of the curve, or at best first part of early majority. the solution needs to now be skewed towards the rest of early and late majority - whose  requirements are "Don't charge me a load of money for the change, don't make me worse off long term, don't  totally disrupt my house, keep me warm, and if you can do that whilst making things greener, that's great".

Posted by: @jamespa

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I know I'm being a bit provocative, that's (as I admit above) deliberate.  But its also necessary if we are to get out of the current rut which leads inexorably to heat pumps remaining a minority interest in this country.  We need to think out of the box, think the unthinkable, until we find a sweeter spot than the one we are currently in.  I'm not saying I have the solution, but some thought around the proposal will, I'm pretty sure, get us to a better place than we are today.

 

so if I understand you right, your (deliberately provocative) position is simply - swap the gas boiler for HT HP and change little or nothing else? In which case I still say,  that'd probably keep the house warm, and be simple and cheap(ish) to install: but the run cost is highly like to be bonkers. That only gets solved (without the aforementioned emitter and cylinder changes etc) is by making the run cost comparable at source - either by the market electricity cost actually coming down, so that a HP with a SCOP of 1.5 is the same run cost as Gas, or some kind of tariff that meters HP use separately, if that were possible. there is also one engineering thing that needs to be considered - flow rate. even if the HP has the same LWT as the boiler and thus in theory the exact same emitter, cylinder , pipework can be used to get the same heat output to the property - the DT needs of the HP will require a substantially higher flow rate, which might not be achievable without those changes.  the answer will always be house-specific (so we're back to "not a simple swap"). Unless someone can build HP's that run nicely at DT20. 

I think that the price ratio of Electicity to Gas is largely responsible for the UK's reluctance to embrace heatpumps.  I understand that it will come down in the next few years, and then I expect it will be easier to install a heatpump and have lower bills than with a gas boiler.  Attached graph showing the UK is almost at the "top" of the table 🙄 .

The Graph below came from here:  https://www.researchgate.net/figure/The-COP-h-of-air-source-heat-pump-operated-with-R32-under-varied-outdoor-air-and-supply_fig2_320762600

While it's COP, not SCOP, I think the graph trend will be the same or very similar.  You can just about get a factor of two in the COP, depending on the heat emitter size assuming weather compensation is correctly set up.  While I agree with the sentiment of "just get a heatpump, don't worry about the COP & SCOP" - it's a rare individual that is willing to pay a higher running cost to save the planet.

There's a lot of heatpumps out there - but they are (imho) a mature technology, and I do not think the fundamental COP will improve significantly now.  High temperature heatpumps - eg R290(propane) is such a high temp refrigerant, and has been around a long time - propane was around 100 years ago in heatpumps!  Details like better automated setup of WC, energy star standby(not yet a thing, but should be), quieter, cheaper, decent measurements, etc will improve though. 

Posted by: @iancalderbank

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understand you right, your (deliberately provocative) position is simply - swap the gas boiler for HT HP and change little or nothing else?

Thats the provocative statement yes, but OK its the extreme to stimulate out of the box thinking.  Currently most HP retrofits seem to involve changing almost everything, the opposite extreme.  Somewhere in between probably lies the right answer

Posted by: @iancalderbank

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That only gets solved (without the aforementioned emitter and cylinder changes etc)...

That's an assumption, not necessarily a truth!

Lets take the cylinder change - why do we do it?  Answer (principally) because a larger coil is necessary to deal with a delta T of 5C and a flow temp of (generally) 55.  Well that's true at a flow temperature of 55, but not true at a flow temperature of 65, provided the HP modulates sufficiently.  Also, there are ways to increase the 'coil area' without replacing the cylinder.  Mixergy, in their heat pump conversion kit, offer a pump and plate heat exchanger to augment their small coil by pumping the water through the PHE (much like happens in a combi boiler).  Why not offer that concept as an add on, much cheaper (and much, much less disruption), than swapping out a cylinder. 

Alternatively, and even simpler still, use the heat pump (running at the standard 55 for HPs in a DHW cycle (or 60) to heat to 40 (or 45) and the immersion heater (or better still a Willis heater fitted low down on an external loop) to do the final push to 50.  For a typical sized tank this would cost about an extra £120 per year at current electricity prices.  That penalty (at inflated electricity prices) means that the business case for swapping out the DHW cylinder is absolute pants!

Now lets look at the feeds.  Its frequently argued that the feeds to the rads don't have sufficient capacity at DT5.  Well sometimes that's true, particularly (but not always) where microbore has been fitted.  But in most cases probably not.  The vast majority of the UK housing stock is two storey, and its a fair bet that there is a separate upstairs and downstairs loop.  So if this plumbed in 22mm, which in most cases it is, you have 6-8kW per floor, much more than enough for most houses.  So replumbing in 28mm is necessary only up to the point they split and, if this is not somewhere that's noise sensitive you could run this at 1.5m/s meaning that even this is only necessary for installations >9kW.  heat geek recently did a video on this point and basically say what I am saying.  They are typically fairly perfectionist so if they also say it I think its almost certainly right.

So onto the rads themselves.  Many houses have had upgraded insulation since the rads were fitted and thus will have oversized rads.  As it happens this is the area where there is most bang for the buck in upgrading (whether the buck is measured in money terms or disrpution terms), so I would probably accept that upgrades are frequently a good idea, provided that the customer is offered the option (or several options).  I may want to do the upgrades or I may not, and that should be my choice, separately priced, with approximate savings if I do.  Some customers may choose not to do the upgrades for purely aesthetic reasons, again it should be their choice not the installers.  Provided they are told the trade-offs that's entirely fair.

Currently we (by which I mean the industry) bundle all of the upgrades and insists that they are essential.  They aren't.

@jamespa

There is no such thing as a 'standard real world situation', if identical heat pumps were to be installed on your home and your neighbour's home, they would undoubtedly produce different results.

The standard data provided by manufacturers is the closest thing that you will get to comparing apples with apples, and is obtained using standard testing procedures as detailed by EN14511 or OM-3-2015.

I suspect that real world operation would struggle to match the standard test data.

Samsung's own data provides the following COP values for a 12kW HT heat pump:-

Amb.   LWT = 55C   LWT = 60C   LWT = 65C   LWT = 70C

-2C            2.74           2.52             2.23             2.17

 7C            3.4             3.06             2.71             2.44

15C           3.82           3.48             3.06             2.77

Whilst the COP values in the above table may not look too bad, I suspect that real world values could be significantly lower.

I do agree with your sentiment that people should be given the choice, but it should also be made abundantly clear that money saved on the installation, would be eaten by higher running costs in the subsequent years.

I don't have any proof, but I suspect the much of the present £5000 grant goes directly into the pockets of the installers and manufacturers in the form of inflated prices. The same happened with solar PV systems, that are now half the price I paid over 10 years ago. The Scottish system of interest free loans may be a better option to help reduce prices and deter the cowboys.

Another possible thing to think about for @iancalderbanks list is an independent heat loss survey function, together with some protection for the installer if they have followed the survey or deviated from it only at the customers request.  Today, the way it works (so far as I can tell), is that you buy the survey (for about £300, sometimes suppliers offer for free) from the heat pump supplier. 

So a) its effectively tied to that supplier (because what supplier will rely on a survey done by another supplier and b) the surveyor is incentivised to tilt the outputs in favour of that supplier.  Some sort of independent survey with a guarantee attached could turn this upside down.  I get my survey done, then go to suppliers for quotes.  It should help suppliers too because they would get a higher 'hit' ratio.

For what its worth I have so far had a bad experience with these surveys.  Two done (each taking 2.5hrs and on the surface very through), both coming out with about 16kW load.  I did my own calculations using the MCS assumptions, and got to 10.5kW.  The differences are I took into account fabric upgrades which I told the surveyors about in both cases.  For one survey only I asked for the detailed calculations and it turned out that they had completely ignored the fabric upgrades.  In addition they had double counted by accounting for room-room losses (which is arguably correct for sizing radiators) but not room to room gains.  If you are going to count room to room losses you need to subtract the room to room gains when sizing the system as a whole.  I can only presume that the second surveyor did similar.

Now my actual measured demand is 7.5kW, even less than I calculate, which I put down largely to poor ventilation (thus lower ventilation losses than the MCS assumptions.  16kW vs 10.5kW (or at the extreme 7.5kW) makes one hell of a difference to the system engineering and drives all sorts of unnecessary expense.

Posted by: @derek-m

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Samsung's own data provides the following COP values for a 12kW HT heat pump:-..

With a design LWT of 65 and WC applied, the system will spend most of its time (in the South East of England) at an LWT in the low 50s or better, typically achieving a COP (based on the specs) of 3.8+.  Its very rare we have sub zero temps and much more common that temps are 7+ (again in the South East of England)

As it happened I did the simulation for the Samsung HT HP also, I just didn't quote it.  Average calculated SCOP based on South of England temperature distributions, 65 flow temp and reasonably but not perfectly adjusted WC - 3.6.  That leaves some margin between this figure and the 3.0 required to achieve price parity at current gas/electric price ratios.

However do please see also my comments in response to @iancalderbank.  Im taking an extreme position (dot change anything) to counter the extreme position taken by the installation industry (change everything.  In reality I suspect the answer is somewhere inbetween (but different for different people); I explore that upthread.

In the end I'd settle for being given the choice.  Today the industry tells us what we 'must have'.

Incidentally I'm not sure I entirely buy the often quoted 'early adopter' argument.  The only technology which is new (and not very new) is the heat pump itself.  Everything else is well past the early adoption phase.  So getting through this phase alone wont solve the price problem.  Installer rates would have to go negative to offset the materials cost of the stuff that is functional but thrown away!

Posted by: @derek-m

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I don't have any proof, but I suspect the much of the present £5000 grant goes directly into the pockets of the installers and manufacturers in the form of inflated prices. The same happened with solar PV systems, that are now half the price I paid over 10 years ago. The Scottish system of interest free loans may be a better option to help reduce prices and deter the cowboys.

i fear you may be right!

The blog on this forum compares installed SCOP to manufacturers datasheets, giving overall average of 2.7:

https://renewableheatinghub.co.uk/how-to-correctly-install-heat-pumps-so-that-they-work-properly-and-efficiently

Posted by: @robl

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The blog on this forum compares installed SCOP to manufacturers datasheets, giving overall average of 2.7:

Thanks.  My first reaction is that's scary.  It looks like the average predicted is (about) 3.5 and the average actual is 2.7.  The latter doesn't match gas in cost, so if its representative then its toast for heat pumps (and the planet) at present. 

SCOP is, of course, the reciprocal of the interesting fact, ie how much energy is consumed; this data shows (based on the averages) 30% more energy consumed than predicted.  Not sure that's any less scary.  If actual = 30% more than predicted is correct, then predicted SCOP needs to be 3.9 to get an achieved SCOP of 3.0 (the current target for equal-cost-to-run gas retrofit).  Thats currently unachievable at anything above about 45-50C.  If the electric/gas price ratio were to reduce to 2.5 to 1, then the predicted SCOP would need to be 3.2 on the same basis (actual = 30% worse than predicted), which looks, based on my modelling and the manufacturer data, achievable at 65C, at least in the South of England.  Altogether not great news though.

However....

What is even more scary, but perhaps also more interesting, is that there appears to be almost no correlation at all between predicted and actual, and the absolute floor of 2.50 (I added the 0 for a reason - to emphasise that this is almost certainly an artefact) is rather suspicious.  Given the total absence of correlation and the artificial floor, does this data actually make any sense at all I ask.  Frankly I don't know!

I had a skip read of the article from which this comes.  The author speculates (and then backs up with experiments) that the poor performance is due to on/off control and buffer tanks, rather than long and slow (or whatever you want to call it).  That's plausible, but doesn't obviously explain the total lack of correlation or the floor.  He claims that on/off is the majority type of control in the UK and, when the article was written, (or even now) he may be right.  In fact he expressly states that 'Unfortunately, as things stand today, most manufacturers, merchants and the majority of training organisations recommend the installation of third party thermostats and buffer tanks or system separation as a design strategy for heat pumps'.  I'm not sure the first part of this is true anymore (apart from outliers like Grant), but the second part perhaps is still true, although that is also reducing as modulation begins to be appreciated.  Also some, at least, are realising that a badly set up/badly designed 4 port buffer is an instant 10% efficiency penalty (or more) not a panacea for all problems.

If the author of the article you cite is correct about the cause of the poor performance, there is actually, contrary to the scary initial reaction, enormous room for optimism!  I will read and digest the article further over the next couple of days.  

There is some data at https://heatpumpmonitor.org/ which seems, prima facie, to paint a rather more optimistic picture of the average achieved, albeit this data doesn't tell us the predicted.  

If only we had some more data, with the key factors which determine actual vs predicted teased out in the data.