I’m looking for a algorithm to calculate thermal output KW/h.
My heat pump have a DC water pump.
Over Modbus/ mqtt is possible read follow l/min and flow and return temperature.
The issue is first minute data and when is defrosting.
You’ll need to do a mass flow rate calculation, see: https://docs.openenergymonitor.org/heatpumps/basics.html#mass-flow-rate-heat-transfer, you can do this in Emoncms input processing.
You want to include minus data for defrost in the calculation since this is heat being subtracted from the house, but it’s a very small amount.