Water flow energy sensor / heat meter DIY (not just water flow)

ESPHome
9

Yes! It was pretty easy after all.

My solution consists of four key entities, two generated by my microcontroller in ESPHome, two derived inside Home Assistant.

Entities:

  • Absolute increasing water volume (in L) - ESPHome
  • Absolute increasing energy consumption/production (in kWh) - ESPHome
  • Relative water flow (in L/min) - in Home Assistant
  • Relative average power (kW average over a moving window) - in Home Assistant

image

ESPHome

(Beware that I have everything twice. Could certainly be templated)

Home Assistant

Intermediary step:

sensor:
  - platform: derivative
    name: Heizungsregelung Heizkreis Volumenstrom ZWISCHENSCHRITT
    source: sensor.heizungsregelung_heizkreis_volumen
    unit_time: min
    time_window:
      seconds: 30
    round: 1

  - platform: derivative
    name: Heizungsregelung Heizkreis Leistung ZWISCHENSCHRITT
    source: sensor.heizungsregelung_heizkreis_energie
    unit_time: h
    unit: kW
    time_window:
      seconds: 60
    round: 2

The interesting entities for water flow and power

template:
  - sensor:
      - name: Heizungsregelung Heizkreis Volumenstrom
        unique_id: uniqueid__heizungsregelung_heizkreis_volumenstrom_l_min
        unit_of_measurement: "L/min"
        icon: mdi:waves-arrow-right
        state_class: measurement
        #device_class: water_rate  # doesn't exist
        state: >
          {{ states('sensor.heizungsregelung_heizkreis_volumenstrom_zwischenschritt') | float(0) }}
        availability: >
          {{ states('sensor.heizungsregelung_heizkreis_volumenstrom_zwischenschritt') not in [ 'unavailable', 'none', 'unknown' ] }}

      - name: Heizungsregelung Heizkreis Leistung
        unique_id: uniqueid__heizungsregelung_heizkreis_leistung
        unit_of_measurement: kW
        state_class: measurement
        device_class: power
        state: >
          {{ states('sensor.heizungsregelung_heizkreis_leistung_zwischenschritt') | float(0) }}
        availability: >
          {{ states('sensor.heizungsregelung_heizkreis_leistung_zwischenschritt') not in [ 'unavailable', 'none', 'unknown' ] }}

Daily energy consumption:

utility_meter:
  heizungsregelung_heizkreis_energie_daily:
    name: Heizungsregelung Heizkreis Energie täglich
    unique_id: uniqueid__heizungsregelung_heizkreis_energie_daily
    source: sensor.heizungsregelung_heizkreis_energie
    cycle: daily

Hope this helps! Let me know in case you need more details

1 Like