ESPHome ERV

erv.yaml

substitutions:
  exhaust_pwm_pin: GPIO26 
  exhaust_rpm_pin: GPIO27
  exhaust_min_power: "0.2"
  exhaust_max_power: "1.0"
  exhaust_power_scale: "1.0"
  exhaust_min_rpm: "300"
  exhaust_max_rpm: "2000"
  exhaust_pulse_per_rotation: "2.0"

  intake_pwm_pin: GPIO14
  intake_rpm_pin: GPIO13
  intake_min_power: "0.2"
  intake_max_power: "1.0"
  intake_power_scale: "1.0"
  intake_min_rpm: "300"
  intake_max_rpm: "2000"
  intake_pulse_per_rotation: "2.0"

  status_pin: GPIO2
  onewire_pin: GPIO33

esphome:
  name: erv
  friendly_name: Energy Recovery Ventilator
  min_version: 2024.12.0

  on_boot:
    - priority: 500 # after sensor setup, before wifi
      then:
        - component.update: co2_pid_float
        - script.execute: update_fan_speed

esp32:
  board: esp32dev
  framework:
    type: arduino

logger:
  level: WARN

api:
  id: ha_api
  encryption:
    key: !secret hrv_api_key

ota:
  - platform: esphome
    password: !secret ota_password

wifi:
  ssid: !secret wifi_ssid
  password: !secret wifi_password

web_server:
  version: 3
  ota: False
  include_internal: True
  sorting_groups:
    - id: sorting_group_control
      name: "Control"
      sorting_weight: 1
    - id: sorting_group_fans
      name: "Fans"
      sorting_weight: 2
    - id: sorting_group_efficiency
      name: "Efficiency"
      sorting_weight: 3
    - id: sorting_group_other
      name: "Other"
      sorting_weight: 50

time:
  - platform: homeassistant
    id: homeassistant_time

one_wire:
  platform: gpio
  id: onewire_bus
  pin:
    number: ${onewire_pin}

output:
  - platform: ledc
    id: exhaust_fan_pwm
    pin:
      number: ${exhaust_pwm_pin}
      mode: OUTPUT_OPEN_DRAIN
    frequency: 25000
    channel: 0
    min_power: ${exhaust_min_power}
    max_power: ${exhaust_max_power}
    zero_means_zero: true

  - platform: ledc
    id: intake_fan_pwm
    pin:
      number: ${intake_pwm_pin}
      mode: OUTPUT_OPEN_DRAIN
    frequency: 25000
    channel: 2
    min_power: ${intake_min_power}
    max_power: ${intake_max_power}
    zero_means_zero: true

light:
  - platform: status_led
    id: status_led_light
    name: Status LED
    internal: True
    pin:
      number: ${status_pin}
      ignore_strapping_warning: true
    web_server:
      sorting_group_id: sorting_group_other

fan:
  ##############################
  # Fan Control
  ##############################
  - platform: template
    id: fan_control
    name: Fans
    restore_mode: RESTORE_DEFAULT_OFF
    preset_modes:
      - Exchange
      - Exhaust
      - Intake
    on_turn_on:
      then:
        - script.execute: update_fan_speed
    on_turn_off:
      then:
        - script.execute: update_fan_speed
    on_preset_set:
      then:
        - script.execute: update_fan_speed
    web_server:
      sorting_group_id: sorting_group_control

sensor:
  ##############################
  # Fan Speed
  ##############################
  - platform: pulse_counter
    pin:
      number: ${exhaust_rpm_pin}
      mode: INPUT_PULLUP
    id: exhaust_fan_rpm
    name: Exhaust Speed
    icon: mdi:gauge
    unit_of_measurement: 'rpm'
    accuracy_decimals: 0
    use_pcnt: False
    internal_filter: 1ms # 2000 rpm: 1/(2*2000)*60 = 0.015ms
    count_mode:
      rising_edge: DISABLE
      falling_edge: INCREMENT
    update_interval: 5s
    filters:
      - lambda: "return x / ${exhaust_pulse_per_rotation};"
      - clamp:
          min_value: 0
      - clamp:
          max_value: ${exhaust_max_rpm}
          ignore_out_of_range: True
      - sliding_window_moving_average:
          window_size: 4
          send_every: 12
          send_first_at: 2
      - round_to_multiple_of: 5
    web_server:
      sorting_group_id: sorting_group_fans

  - platform: pulse_counter
    pin:
      number: ${intake_rpm_pin}
      mode: INPUT_PULLUP
    id: intake_fan_rpm
    name: Intake Speed
    icon: mdi:gauge
    unit_of_measurement: 'rpm'
    accuracy_decimals: 0
    use_pcnt: False
    internal_filter: 1ms
    count_mode:
      rising_edge: DISABLE
      falling_edge: INCREMENT
    update_interval: 5s
    filters:
      - lambda: "return x / ${intake_pulse_per_rotation};"
      - clamp:
          min_value: 0
      - clamp:
          max_value: ${intake_max_rpm}
          ignore_out_of_range: True
      - sliding_window_moving_average:
          window_size: 4
          send_every: 12
          send_first_at: 2
      - round_to_multiple_of: 5
    web_server:
      sorting_group_id: sorting_group_fans

  ##############################
  # C02
  ##############################
  - platform: homeassistant
    id: co2_pid
    name: CO2 PID
    icon: mdi:molecule-co2
    internal: True
    entity_id: sensor.co2_pid
    accuracy_decimals: 1
    filters:
      - debounce: 3s
      - clamp:
          min_value: 1
          max_value: 100
    web_server:
      sorting_group_id: sorting_group_fans
  
  - platform: template
    id: co2_pid_float
    name: C02 PID float
    icon: mdi:molecule-co2
    internal: True
    accuracy_decimals: 3
    lambda: |-
      if (isnan(id(co2_pid).state)) {
        // Ignore 'unknown' state if connected to Home Assistant.
        if ( id(ha_api).is_connected() ) {
          return {};
        }
        return 0.5;
      }
      return id(co2_pid).state / 100.0;
    update_interval: 5s
    filters:
      # - filter_out: NAN
      - sliding_window_moving_average:
          window_size: 30
          send_every: 1
          send_first_at: 1
      - round: 5
      - clamp:
          min_value: 0
          max_value: 1
    on_value:
      then:
        script.execute: update_fan_speed
    web_server:
      sorting_group_id: sorting_group_fans


  ##############################
  # Temperature & Efficiency   #
  ##############################
  - platform: dallas_temp
    one_wire_id: onewire_bus
    id: exhaust_input_temp
    name: "Exhaust Input Temperature"
    icon: mdi:thermometer
    address: 0xF0F0F0FF0F0F0FF0
    accuracy_decimals: 2
    update_interval: 7s
    filters:
      - filter_out: nan
      - offset: 0.3
      - clamp:
          min_value: 10
          max_value: 30
          ignore_out_of_range: True
      - throttle_average: 60s
    on_value:
      then:
        component.update: efficiency
    web_server:
      sorting_group_id: sorting_group_efficiency

  - platform: dallas_temp
    one_wire_id: onewire_bus
    id: intake_input_temp
    name: "Intake Input Temperature"
    icon: mdi:thermometer
    address: 0xFF00FF00FF00FF00
    accuracy_decimals: 2
    update_interval: 10s
    filters:
      - filter_out: nan
      - clamp:
          min_value: -20
          max_value: 40
          ignore_out_of_range: True
      - throttle_average: 60s
    on_value:
      then:
        component.update: efficiency
    web_server:
      sorting_group_id: sorting_group_efficiency

  - platform: dallas_temp
    one_wire_id: onewire_bus
    id: intake_output_temp
    name: "Intake Output Temperature"
    icon: mdi:thermometer
    address: 0xFFFF0000FFFF0000
    accuracy_decimals: 2
    update_interval: 8s
    filters:
      - filter_out: nan
      - offset: 0.5
      - clamp:
          min_value: 0
          max_value: 30
          ignore_out_of_range: True
      - throttle_average: 60s
    on_value:
      then:
        component.update: efficiency
    web_server:
      sorting_group_id: sorting_group_efficiency

  - platform: template
    id: efficiency
    name: "Efficiency"
    icon: mdi:home-percent-outline
    state_class: measurement
    unit_of_measurement: "%"
    accuracy_decimals: 1
    update_interval: never
    lambda: |-
      if (
           isnan(id(intake_output_temp).state) 
        || isnan(id(intake_input_temp).state) 
        || isnan(id(exhaust_input_temp).state)
      ) {
        return NAN;
      }

      // When cold outside, 
      if (
        id(intake_input_temp).state <= id(exhaust_input_temp).state
        &&
        (
          // fresh air must be colder
          id(exhaust_input_temp).state <= id(intake_output_temp).state
          ||
          // outside must be at least a degree colder 
          id(exhaust_input_temp).state - id(intake_input_temp).state < 1
        )
      ) {
          return NAN;
      }

      // When warm outside, 
      if (
        id(intake_input_temp).state > id(exhaust_input_temp).state
        &&
        (
          // fresh air must be warmer
          id(exhaust_input_temp).state >= id(intake_output_temp).state
          || 
          // outside must be at least a degree warmer
          id(intake_input_temp).state - id(exhaust_input_temp).state < 1
        )
      ) {
        return NAN;
      }

      return 
        ( id(intake_output_temp).state - id(intake_input_temp).state ) 
        / 
        ( id(exhaust_input_temp).state - id(intake_input_temp).state )
        * 100.0;

    filters:
      - debounce: 5s
      - lambda: |-
          if (
               id(exhaust_fan_rpm).state > ${exhaust_min_rpm} 
            || id(intake_fan_rpm).state > ${intake_min_rpm}
          ) {
            return x;
          }
          return NAN;
      - round: 1
      - clamp:
          min_value: 0
          max_value: 100
          ignore_out_of_range: True
      - throttle_average: 60s
    web_server:
      sorting_group_id: sorting_group_efficiency

script:
  - id: update_fan_speed
    mode: restart
    then:
      - script.execute:
          id: set_fan_speed
          mode: !lambda |-
            return id(fan_control).preset_mode;
          value: !lambda |-
            return id(co2_pid_float).state;

  - id: set_fan_speed
    mode: restart
    parameters:
      mode: string
      value: float
    then:
      - if:
          condition:
            - fan.is_on: fan_control
          then:
            - if:
                condition:
                  - lambda: return mode == "Intake";
                then:
                  - output.turn_off: exhaust_fan_pwm
                else:
                  - if:
                      condition:
                        - lambda: return mode == "Exhaust";
                      then:
                        - output.set_level:
                            id: exhaust_fan_pwm
                            level: 1.0
                      else:
                        - output.set_level:
                            id: exhaust_fan_pwm
                            level: !lambda |-
                              return fminf(1.0, value * ${exhaust_power_scale} );
            - if:
                condition:
                  - lambda: return mode == "Exhaust";
                then:
                  - output.turn_off: intake_fan_pwm
                else:
                  - if:
                      condition:
                        - lambda: return mode == "Intake";
                      then:
                        - output.set_level:
                            id: intake_fan_pwm
                            level: 1.0
                      else:
                        - output.set_level:
                            id: intake_fan_pwm
                            level: !lambda 
                              return fminf(1.0, value * ${intake_power_scale} );
          else:
            - output.turn_off: exhaust_fan_pwm
            - output.turn_off: intake_fan_pwm