EmonHP - how to create flow rate feed

Emoncms
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Hi,

I’ve got the level 3 heat pump monitoring setup. Is there a way to work out the flow rate? I can see a volume reading but this is around 2,500 and I can’t figure out how that would relate back to the 15-25 litres per minute the LG controller shows. The system has some glycol (which the heat meter was calibrated for) but I don’t know exactly how much so would struggle to figure out a specific heat capacity.

My LG heat pump controls the flow rate based off some in-built logic, which it calls ‘optimal flow rate’, and I understand LG trains installers to commission with this setting. You can change it to fixed dT (but only 6C+ delta!), or fixed flow rate. I’d like to create a flow rate feed so I can map out the flow rate it’s using against the COP to confirm that, as you’d expect, this is indeed optimal.

Thanks in advance for any help. I assume the inputs are the same for all emonHPs but happy to paste a screenshot if not.

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You don’t say which heat meter you have (I believe the emonHP comes with either Sontex or Kamstrup).

The Sontex definitely provides a flow rate input over mbus; just multiply it by 16 2/3 to get l/min into a feed.

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That’s very helpful - thanks!

It’s a Sontex Supercal 5. The multiplier means I’m looking for a figure in the 1-1.5 region so (tomorrow) I’ll check that and see if the Sontex display gives me an exact figure to match.

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Thanks again. Found it by comparing the numbers on the Sontex with the inputs.
It comes through under input heatmeter_Record14 as m3/h but without any decimal points. Division by 100k then multiplication by 16 2/3 (as you say) to convert to litres per min.

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And so the LG optimal flow rate begins to reveal itself. My Heatpump app

Essentially, it looks to go full blast (30lpm) until it reaches temperature, then drop the flow rate to retain a high (5-6C) dT.