Heat Pump Monitoring (and expand to solar later)

Hi all,

A pal of mine has had a LG Therma V heat pump installed and there is no monitoring included. All looks poor and the only offering is a £200 wifi dongle that doesn’t look like it brings much to the table.

After showing him @TrystanLea latest graphs etc showing COP he was interested, but I need to price this up for him.

As I already own an emonPi and 2 x emonTX I was thinking something similar, but I don’t know enough about the heat pump board to know what combo of things to recommend buying.

What we want to monitor:
Ideally I think we’ll need 4 CT clamps (heat pump, grid, immersion and a spare for later), so I’m drawn to an emonTX.
Note: he will hopefully add another emonTX in his garage once he gets Solar, Battery and EV in there.

Flow and Return (plus perhaps other temps), so get some DS18B20 sensors hung off a terminal box breakout off the TX.

Qalcosonic E3 heat meter - is this still the goto heat meter? Any recommended places to buy from? Is the only option to be sure about matching the pipe sizing?

I then think we’d get the emonbase and M-Bus to USB Converter board. (is there a cable that connects the MBUS board to the heat meter?)

I’ve never owned a emonbase, just an emonpi, so no different really apart from the lack of screen?
Looking into the future, should we worried about no space for an aerial? Especially if adding another TX later (that will be the other side of the house in the garage).

Does that sound about what we’d need?
Any help with this would be appreciated.

Cheers, Mick

Hello Mick, Good questions and sounds like a great project!

Your general plan the EmonTx sounds great and using DS18B20’s connected to a terminal block breakout. Would be good to get flow, return and outside temperature, might be useful to add cylinder temperatures and temperatures on other components, different circuits, either side of a buffer if your friend has one? That might be more on the advanced side of things, if you wanted to add that later.

On the heat meter side of things, we’ve got a guide here on selecting a suitable heat meter HeatpumpMonitor/selectingheatmeter.md at master · openenergymonitor/HeatpumpMonitor · GitHub the first question is does the heating circuit contain glycol? If it does then the Sontex heat meters are the only meters (available through Stockshed at least) that can be calibrated for glycol. That does get expensive and a bit complicated to install of course as you have to drain the system or segment of pipe, cut the pipe and connect it in.

It’s obviously really nice to measure the heat output accurately with a heat meter as you can then get the COP but you can also learn a lot with just electric consumption and system temperatures.

@johncantor did a good video overview of using an emonTx with temperatures for monitoring a heat pump here Introduction to heat pump monitoring hardware - YouTube.

Yes the emonBase runs exactly the same software as the emonPi but does not have the energy monitoring board and LCD, it’s just a PI with a simple 433Mhz radio receiver. The emonBase has a wire aerial.

Hope that helps!

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That’s all spot on @TrystanLea , thank you, makes a lot of sense.

I will look to get him to buy the emonbase, emonTX, the breakout board and temp probes for starters.

Then i’ll pop up and get it him all setup. :slight_smile: