Mitsubishi Ecodan Monitoring and Control Upgrades

I’ve been reading about some of the advanced users on here optimising their heat pump efficiency and I’d like to do the same.

I’ve got a pair of 12kW Ecodan units connected to FTC5 controllers that were installed in 2016 and I’m sure they could be running more efficiently. Last year we consumed around 30k kWh of electricity, the bulk or which is attributed to the Ecodans (a little EV charging in the mix), we’re heating circa 5k sq.ft. of 2016 new build in the South East of England for reference.

I’ve recently had the system serviced by a Mitsubishi engineer who found some issues with the original installation and now would seem like the ideal time to add some additional sensors etc. if I’m going to have the remedial work done.

As I understand the system only has the basic (EMP1?) monitoring package in place (no RHI as new build), I upgraded both units with the WiFi interface last year so I can monitor/control through the MELCloud app/API.

Monitoring/control equipment wise today I have the following;

  • 2 x FTC5 Controllers with WiFi modules
  • emonpi and emontx with pulse sensor (recording PV generation) and CT sensors
  • 3-Phase smart meter connected to Glowmarkt Bright app/API
  • Home Assistant (using integrations to connect emoncms/melcloud/glowmarkt etc.)

I’m pulling some data into emoncms via the MELCloud integration for Home Assistant currently, such as flow and return temperatures plus outdoor, indoor and hot water temperatures.

What would you guys recommend I add to my system from a monitoring perspective? Flow meter(s)? Heat meter(s)?

Also, should I go Mitsubishi EMP3 or home brew? I’ve had some (ongoing) issues with the Mitsubishi cloud service as both units intermittently stop updating the flow/return and hot water temperatures in the MELCloud app, so I’m swaying towards being self-sufficient.

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Hello @Dan_Nichols what are you able to tell from the data at the moment? can you see flow temperatures? do you have a CT from the emonpi/emontx that can isolate just the heat pump component? What do the graphs look like?

You should be able to get a lot of insight with what you already have, maybe enough to do some optimisation? It’s obviously nice to have heat metering as you can then accurately measure COP and so more easily monitor the effectiveness of optimisations but it’s not necessarily required.

I would personally do a separate system to the EMP3 as you can then pull out more data from the heat meters via MBUS and at higher resolution, there may be some scope to do both with the same heat meter, I think the Mitsubishi system uses the pulse output from the heat and electric meters, I may be wrong about that. You could then have the data both through MEL Cloud and seperatly via MBUS direct to a Pi… You’d just need to make sure that the heat meter and electric meters have MBUS outputs…

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Hello @TrystanLea, thank you for taking the time to reply. I’m not able to tell much at the moment as I’ve only just realised I can export some of the MELCloud data to emoncms via Home Assistant and I’m suffering with the apparent MELCloud API throttling issue that I’ve seen a few of the members on here discussing. I’ve tweaked the Home Assistant MELCloud integration to reduce the API calls from 60 to 120 seconds so once they start updating my data (stopped around 20:30 last night) I’ll see if that gives me a more reliable data feed.

The heat meter feels like a good step forward as I’m in for a few £k of upgrades to get my system on the Mitsubishi diamond cover anyway. Any suggestions on what heat meter model you would recommend and exactly where in the system this should be installed would be appreciated.

The engineer also mentioned that the type of flow meters I have installed at the moment can be problematic down the line so I might look at replacing those (although they may be covered under the maintenance contract in future).

What type of electric meter do you recommend? I’ve been using some 100A CT clamps with emontx which I don’t think are very accurate - I’ve got two side by side reading ~50-100W apart most of the time and another that appears faulty and stopped reading altogether. Perhaps it is because they are too large for the application? (thin wire with large CT clamp)

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My recently installed Ecodan has the Sika Vortex meter. The FPC 6 is reading an analogue voltagd output. Ive piggybacked a ESP8266 NodeMCU onto the output (directly as the max is 3.6V, but thats for unachievably high flow rates - normally its about 1V) and im powering the ESP8266 from 5v flow meter supply. Im then sending that direct to Emoncms. It seems to work!


Hello @Dan_Nichols, we’ve written a piece on selecting the right heat meter here HeatpumpMonitor/ at master · openenergymonitor/HeatpumpMonitor · GitHub, do you have a diagram of how the system is plumbed together?

I’ve been using the SDM120 electric meters for class 1 metering with heat pumps, you can read these with either modbus or mbus depending on which variant you order.

@Rachel that’s a nice solution, @Dan_Nichols do you by any chance have any Sika vortex flow meters on yours already? Looks like this: