@davidalgave

I would say that most uk installations do not have robust system reporting as standard. I can recommend openenergymonitor and use it myself.

@bontwoody As we have the Homely smart controller, I asked at the time of installation for access to the dashboard data. This is in its’ early iterations and intended for the use of the installer and in a You Tube presentation, the designer explained that they were giving access to installers by popular demand but, to bear in mind that the dashboard as presented is a ‘work in progress’ - I look forward to seeing it evolve in the future. Regards, Toodles.

@toodles That sound like it would be useful and a good selling point if robust

Posted by: @bontwoody

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I can recommend openenergymonitor and use it myself.

Thanks bontwoody.

Because of Brexit, I guess that would cost me the best part of €1000 with shipping and duty and then there wood be the cost of fitting.  I would find that difficult to justify when it would be used over a short period to optimise the system.

I suppose I could fit a three phase meter for consumption fairly cheaply, but measuring output would be a different matter. 

Going back to my original question, if I used the figures from the FTC5 or MelCloud, how inaccurate would I be?

Posted by: @davidalgarve

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Going back to my original question, if I used the figures from the FTC5 or MelCloud, how inaccurate would I be?

I have used both on the same system and the previous internal measurements of COP were very similar to the current externally metered ones.    

Thanks Kev M.

We are having a warm winter in the Algarve, so I can't do much meaningful tweaking of the Ecodan Compensation curve. I have a buffer tank and I am persuaded that the secondary pump is running too fast  and although the pump is variable speed the PWM is not available for it, so at some stage I will change the pump for a more modern version.

That aside, I calculate the January CoP as: From the FTC5 = 3.37 & from MelCloud = 3.39

How does that rate with anyone else?

House is a quite large, 4 bedroom with poor wall insulation but double glazed throughout.  Large Roca aluminium rads. No information on calculated heat loss. 

@davidalgarve 

The figures from the control panel and those from Melcloud should be the same, as yours are. I was talking about using external heat and electricity meters compared with however an Ecodan works it out internally. 

It's hard to compare COPs without knowing your LWT and OAT. When it's 10 deg outside my rads are about 36 deg and my heating COP is around 4. 

I started daily recording the FTC6 heat consumed and delivered figures last February. I paused in the summer (going to weekly) and resumed in October. I wanted two things- to establish a better baseline and to see if I could improve the CoP. 

Once I started recording I quickly noticed that the electricity consumed figure generated by the Ecodan is not consistent with the consumption measured by the meter that just measures the heat pump. (And 'no' this doesn't include any immersion heater consumption.) The difference tends to be that the Ecodan thinks it eats more electricity than the meter measures- in aggregate metered consumption in 2023 was 3138kWh and Ecodan was 3590- over 14% different! I have more confidence in the accuracy of the meter though it measures to 2 decimal places whereas the Ecodan only displays whole numbers so rounding will be a particular factor when consumption is low. In 2023 the maximum daily difference was Ecodan 53% higher and 43% lower.

This is all very frustrating. I have concluded three things:

- I assume that the Ecodan's power delivered figure is as likely to be as unreliable as its power consumed

- I hope that using the Ecodan's figures for both is more likely to give me a consistent representation for whether my tinkering is beneficial for CoP efficiency.

- looking at daily data is time consuming and is not a good basis to endlessly obsess about making frequent small adjustments (to WC curve and/or pump speeds for three different pumps). I only act once week on the basis of weekly totals and not daily. 

Good luck!

(edited for clarity)

@davidalgarve

My surplus power 'consumed' last year was around 630kWh, so around 1.75kWh every day. Some fairly random variation either side of this, not related to consumption, and certainly not a straightfoward percentage overestimate. A standard deduction would get you closer to the figure, but if you want accuracy then the most cost effective would be a standard electric meter (c£40ish?) that has a pulse output which can be plugged into the FTC controller and will replace the units guesstimates with accurate measurements.

glpinxit

I also spent a long period at first noting down daily figures from the controller - most tedious. But then mastered looking at the code generated by MelCloud in a browser window (in my case Firefox >Tools >Browser Tools >Developer Tools> then Network and Response options) and have managed to create an entire history of the unit's performance in a spreadsheet. This is much more useful to make comprisons with.

Posted by: @davidalgarve

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When contributors are quoting CoPs for Ecodan MelCloud setups, how are the obtaining them? I had previously understood that the figures on the e.g. FTC5 were not very accurate and the MelCloud Consumed/ Delivered figures appear to need some interpolation.

Do most UK installers provide external power consumption/ delivery measurement devices? My Portuguese contractors provided no means of measurement, but then that is only one of many of their failings!

I would suggest that you look within the 'Service' menu at the 'Energy monitor settings', since it would appear that the estimated power consumption of external water pumps has to be entered rather than being measured. Obviously even a small difference between the entered value and the actual power consumption will lead to errors over time.

It also depends upon where the power for any external pumps is derived, if it is via the heat pump equipment then it should be included in the value obtained from a heat pump dedicated power meter, but if the water pumps are powered from a separate power source, which is just being switched on and off by the controller, then it will not be measured by the the heat pump power meter.

This may be a problem with most heat pump systems, since the true overall COP should include all the electrical power consumed by the heating system, but the power used by externally powered equipment may not be included in the measurement made by an heat pump dedicated power meter.

I suppose that you could try setting any values found within the 'Energy monitor settings' to zero, and see if the controller calculated power usage reduces and is more inline with any heat pump dedicated power meter.