Posted by: @grahamh

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i have read some I'll informed rubbish in my time but this thread is world class.

... 

If you need help have you considered paying someone who knows what they are doing? Asking keyboard warriors on the web is a great way to get shit advice.

 

I can see why I no longer get involved in after sales. Bloody tedious. 

Almost everyone on this forum has found their way here precisely because they considered paying someone who knows what they are doing ..... only to find they didn’t after all. It seems the best way to get, as you put it, “shit advice” is to ask the first installing company you spot; there are on balance, it appears, more charlatans than professionals out there and those that do do a good job (like the ones who helped me) are like gold dust.

Whilst there is a range of content posted here - some good advice, some questionable - on average it is no worse nor a wider range than forums on any other topic. Moreover, plenty of people have found their competent professional saviour through suggestions and recommendations made here. Your coming on here and dismissing contributors here with condescending terms like “keyboard warrior” is unhelpful. A pity from someone who, as his books make obvious, has it in his capacity to be hugely helpful.

Posted by: @julianc

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@editor I remember your vids and early shut downs with the filter. I thought you got good help from your installer?  They had to add further pumps to get flow around the house?

The installers were helpful and finally moved the filter inside for easier access, but the flow issues persisted which prompted them to add more distribution pumps. No more flow issues, but the phantom running costs have certainly gone up.

Normally this forum is an excellent example of what a forum (forum: a place where people can exchange opinions and ideas on a particular issue) should be. Fora aren't 'the bible' on a subject, they are places where ideas opinions and information, some of it excellent, some of it less so, are exchanged. We are extremely lucky to have a number of knowledgeable people who give freely of their time and expertise. Keyboard warriors are notable by their absence - or were, until 9:48pm yesterday when a classic example appeared, wielding four letter words and slashing abuse in all directions. So hot was this warrior that his spellchecker overheated, and he came out with some I'll (sic) chosen words. I might even manage to do the same.

We know who wrote the Freedom calculator, and have done for some time. In it's native format, large parts of it are hidden (making it a 'black box'), but I have an aversion to black boxes, so I took the necessary steps to unhide the hidden parts. Unfortunately, most installers, mine included, just treat the black box as the oracle. While what you see in the black box is mostly rather clever, it is far from perfect. Rather than say vaguely I have 'loads of evidence' that it is far from perfect, I will show you some.

The calculator is based on the MCS approach, which is pretty standard. Whether it encourages designs with 'loads of headroom' is open to debate. I'd suggest the 'loads of headroom' stem more from decisions the system designer does or doesn't make (like what size heat pump to install). The actual calculations are of course fixed and rigid, 2 + 2 always equals 4, never 5, in a spreadsheet, and MCS itself is notoriously fixed and rigid in its requirements, with in effect a binary (0 or 1, about as rigid as it gets, there is no such thing as headroom in a binary world), and the spreadsheet reflects this: the proposed system gets either a pass or a fail. Very binary, no headroom. 

In the hidden parts of the spreadsheet there are vast arrays of look up tables, stretching into the distance like solar panels across landscape. Much of the work of the spreadsheet is done by looking up data from these tables, and then producing the results the spreadsheets user sees. In passing, praise where praise is due: the formulae used are mind-boggling, GH is to be praised for managing to put them together. A classic example is the heat load vs selected unit output graph. Here's mine as sent to MCS by my installer (I got a copy after it was sent): 

Unfortunately, the heat loss sheet contains a rather inconvenient typo. The external wall length in my largest room got entered as 2.3 metres when in fact it is 12.3 metres. Simple error, easy to make, but it makes a big difference, as we can see in the chart from the corrected version:

There is now no headroom at all. In fact, when you add the DHW, the head pops through the ceiling, into no no land. Nonetheless, the system is a pass, just, with no headroom. Below the chart in the spreadsheet there are some RULES telling what is and is not acceptable, and a table that has the binary outcome, Will the system qualify for MCS, Yes or No. In my case it was a yes, but there is NO headroom: the heat loss is exactly the same as the claimed heat output from the heat pump at design temps, 12.4kW for each figure. I don't see any evidence of MCS encouraging oversizing, or 'loads of headroom'. In fact, I see quite the opposite, no headroom. Here's the table, showing the system is an MCS pass:

Now, and this is most unfortunate, the Freedom calculator guessed the output of the Midea units, and they guessed wrong. Unsurprisingly, they guessed upwards (they do so love their Midea units, better give them the benefit of the doubt). None of this is apparent to the ordinary customer or installer, it is all hidden in the hidden part of the spreadsheet. Look at the blue line in the charts, and the numbers on the line. They come indirectly (there is yet another trick in the spreadsheet pack of tricks, white text on a white bacjground, the actual plotted data is derived data in columns G and H) from tables in the hidden part of the spreadsheet. Note how the three 12.4 values aren't joined by a straight line. The curve is rather clever, it is in fact an X-Y scatter plot with an added smoothed line, that's how it gets the dip for the defrost cycles between 0 and 3 degrees ambient - otherwise, the three identical values would be joined by a straight line. It's really all rather creative, rather like creative accounting, and very pretty. But it is also wrong. And so too is the assertion that the system is an MCS pass. It's not, it's a fail.

Freedom (or rather GH) mostly made up the Midea figures. Buried in the hidden part of the spreadsheet, the part no one normally sees, is a cell with a very telling comment. This is what it says (screen grab for evidential purposes, and no Photoshopping, I promise)

It turned out these figures are over optimistic. We now know, thanks to the diligent thoroughness of certain members of this forum, what the real, or at least the manufacturer's claimed figures (which may also be optimistic) are. Here's the data from the relevant Midea documentation (Midea_A_series_Mono_M-Thermal_Heat_Pump_R32_2020513_V1_7.pdf) showing Midea's claimed output:

My system was designed with a 14kW Midea unit, with a LWT of 55 degrees (a necessary compromise, because small rooms means smaller rads means higher LWT). I've highlighted the relevant cells. Midea use slightly different set points for ambients, 0 and -5, rather than Freedom's 0 and -2, but you can very clearly see that between 0 and -5 degrees ambient, the unit puts out between 11.5kW (at 0 degrees) and 11.1kW at -5 degrees. Let's say that means 11.3kW at - 2 degrees, compared to Freedom's 'mostly made up' (their term) figure of 12.4kW.

Unfortunately, 11.3kW is less than 12.4kW. My system is an MCS fail, despite the fact Freedom claimed it was a pass.

Now, where on earth has all that headroom gone?  

@grahamh, if I'm honest I

Posted by: @grahamh

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If you need help have you considered paying someone who knows what they are doing? Asking keyboard warriors on the web is a great way to get shit advice.

Most people here have paid in excess of £12,000 for their heap pumps to be installed professionally, but the installations have been bodged by incompetent installers that don't know (or don't care) what they're doing. Consequently, systems have been fitted that don't heat houses and are expensive to run. That is unacceptable.

Homeowners have nowhere to turn. The consumer codes don't help and organisations like MCS are toothless. So there are thousands of heat pumps fitted each month, many of which are sadly not fit for purpose. When homeowners question installers they are slapped back with an arrogant "how dare you question my work" attitude.

So why should people pay even more money for another self-professed expert who's probably just another cowboy. The industry, to use one of your own terms, is full of shysters and it's not difficult to see why heat pumps have got a bad reputation with the mainstream media. 

Frankly, the keyboard warriors on this forum have been far more useful to helping struggling homeowners get a grip on their systems that have been bodged. At least we're helping homeowners understand what's wrong because heat pump experts don't have the time of day for after sales. It's all about shifting and fitting units, get those commissions and moving on.  

@kev-m I disagree on the badging issue. Have you seen the way Audi size their cars? 35,40,50 etc just gives a rough indication of the power scale. I see the ASHP 18kW as something similar - it gives a scale for their range. It is incumbent on the designer to understand the system requirements and the spec a solution to meet the client need. But it again comes back to the same point: you need a good heating engineer 

@editor I thought I remembered that Mars. Which circulation pump did they fit?

 
I have a Grunfos Magna 1 variable pump that only consumes 9-151W to pump around 24 radiators. This seems low power and good energy value. But it’s an expensive pump to start with

Posted by: @julianc

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Have you seen the way Audi size their cars? 35,40,50 etc just gives a rough indication of the power scale. I see the ASHP 18kW as something similar

That's not the same thing, as your comment makes clear: the 35, 40, 55 etc are arbitrary vaguely ordinal numbers (could just as easily be 3 4 and 5 or 350 400 and 500 or whatever you want) with no units and no actual relation to HP, they are just model numbers. On the other hand, 18kW has a unit (kW, something you can measure) attached, and so implies actual output. If a unit is described as a Midea 14kW heat pump, a consumer will, and is entitled to assume, it has a 14kW output over its expected in use range. Otherwise, what does the 14kW mean? What not call it a 24kW unit and say it is up to the designer/consumer to discover it is a 11kW unit?

Under your system, supermarkets could sell 1.5kg bags of spuds, and then say it is up to the consumer to discover when they get home and open the bag  that a 1.5kg bag only contains 1.1kg of spuds. All the 1.5kG meant was that it was bigger than a 1kg bag. When there is a legitimate difference in total weight sold and usable contents, eg tinned goods, it is made clear by stating the net weight.    

@cathoderay you make a good point. My first class at university was the importance of Units. 
But I still think it’s down to the heating engineer to pick the right solution for the job.

Posted by: @julianc

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@cathoderay you make a good point. My first class at university was the importance of Units. 
But I still think it’s down to the heating engineer to pick the right solution for the job.

You are correct Julian, you have hit the nail on the head.

Could you please explain to us 'common' people how to identify a 'real' Heating Engineer from someone claiming to be a real heating engineer?

Posted by: @julianc

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@editor I thought I remembered that Mars. Which circulation pump did they fit?

They slapped in two of these in addition to the other two circulation pumps we have and at this time of year they have to run at max.

Could you please explain to us 'common' people how to identify a 'real' Heating Engineer from someone claiming to be a real heating engineer?

That is the million dollar question. We screened six installers. Three were very clearly cowboys, so they were easy to dismiss. The problem is well-presented installers (or sales people) who say the right things, answer your questions and come across as professional are difficult to dismiss as cowboys, so you make a gut call. And frankly, that's not good enough when you're spending in excess of £12,000 for a new heat pump. There should be more guarantees in place.

Ultimately, we screened our installers as best we could and still ended up with a system that runs well below par. Word of mouth is important, but more often than not it's a game of installer Russian roulette. 

@julianc - thanks. 

Posted by: @julianc

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But I still think it’s down to the heating engineer...

I agree, but perhaps more often than not, there isn't a real engineer directly involved. My system was in effect designed by Freedom's flawed calculator, my installer just dialled in the numbers and the black box churned out the answers. I rather expect this is the norm, Freedom plug their calculator as the installer's best friend, and it means anyone who can type numbers into a spreadsheet can appear to be an engineer. If the installer can't enter numbers in a spreadsheet, then I rather suspect that's what part of Freedom's training courses trains them to do.

There are two problems at work here: (a) the industry allows anyone who can work a spreadsheet to appear as if they are an engineer and (b) the black box (the spreadsheet) may be imperfect. These two then get compounded, because the installer, not being an engineer, doesn't spot the problems because they can't see inside the black box. For completeness, there is also at least a third source of error, typos, but those are relatively easy to spot and correct (but I have to add that only happened in my case because I happen to know how to do heat loss calculations, and spotted the fact the total heat loss had to be too low. I suspect most consumers would have no idea of what ball park their heat loss should be in). 

The obvious solution (and this is a suggested answer to @derek-m's question) is a radical restructuring of the industry to have accredited heating engineers, as in engineers who have completed a proper course, and passed an exam at the end of it. MCS could do worse that get off their backsides and set up such a scheme, but they won't, because it will get in the way of their sacred mission, to plug renewables, get units installed regardless of cost or competence, and reward their masters with glorious numbers of completed installations. Such a restructuring would of course cost money, and we the consumer would end up paying, but, hey, if it means we get systems that work, is that really a problem?