Switch a fan based on absolute humidity difference between two humid/temp sensors, with blocking Light Switch

Description
If switching a fan based on the relative humidity difference between two rooms, if there is a temperature difference, the rule does not provide a consistent behavior. Therefor it is needed to calculate the absolute humidity in g/m3 based on the temperature and relative humidity.

This blueprint also contains an input switch (for example the Light) which, if on, blocks the automatically start of the fan.

blueprint without the light switch: Switch a fan based on absolute humidity differnece between two humid/temp sensors

Open your Home Assistant instance and show the blueprint import dialog with a specific blueprint pre-filled.

Requirements:

  • switch for the fan
  • switch for the light
  • temperature
  • humidity
  • reference temperature
  • reference humidity
blueprint:
  name: Humidity Management based on abs. humidity (g/m3); With blocking LightSwitch
  description:
    Turn a fan on and off based on the difference between a humidity sensor
    and a baseline, based on absolute humidity
  domain: automation
  input:
    humidity_sensor:
      name: Humidity Sensor
      description: A sensor that measures the humidity of the area
      selector:
        entity:
          domain: sensor
    temperature_sensor:
      name: Temperature Sensor
      description: A sensor that measures the temperature of the area
      selector:
        entity:
          domain: sensor
    reference_humidity_sensor:
      name: Reference Humidity Sensor
      description: A sensor that indicates the baseline humidity of the location
      selector:
        entity:
          domain: sensor
      default: []
    reference_temperature_sensor:
      name: Reference Temperature Sensor
      description: A sensor that indicates the baseline temperature of the location
      selector:
        entity:
          domain: sensor
      default: []
    fan_switch:
      name: Fan Switch
      description: A switch that turns the fan on and off
      selector:
        entity:
          domain: switch
    light_switch:
      name: Light Switch
      description: A switch that turns the light on and off. If provided,
        the fan will be stopped and not turned on if the light is on.
      selector:
        entity:
          domain: switch
    rising_threshold:
      name: Rising Threshold (in g/m3)
      description: How many gram/m3 above the reference humidity the sensor
        can rise before the fan is turned on.
      selector:
        number:
          min: 0.0
          max: 3.0
          mode: slider
          step: 0.1
      default: 1.1
    falling_threshold:
      name: Falling Threshold
      description: How many gram/m3 above the reference humidity the sensor
        must fall to before the fan is turned off
      selector:
        number:
          min: 0.0
          max: 3.0
          mode: slider
          step: 0.1
      default: 0.9
  #source_url: https://community.home-assistant.io/t/turn-a-fan-on-and-off-based-on-the-difference-between-a-humidity-sensor-and-a-baseline/255999
trigger:
  - entity_id: !input "humidity_sensor"
    platform: state
  - entity_id: !input "reference_humidity_sensor"
    platform: state
condition:
  - condition: template
    value_template: "{{ mode != switch_state }}"
action:
  - service: switch.turn_{{mode}}
    entity_id: !input "fan_switch"

variables:
  temperature_sensor: !input "temperature_sensor"
  humidity_sensor: !input "humidity_sensor"
  reference_temperature_sensor: !input "reference_temperature_sensor"
  reference_humidity_sensor: !input "reference_humidity_sensor"
  fan_switch: !input "fan_switch"
  light_switch: !input "light_switch"
  switch_state: "{{ states(fan_switch) }}"
  block_state: "{{ states(light_switch) }}"
  rising_threshold: !input "rising_threshold"
  falling_threshold: !input "falling_threshold"
  abs_humid_ref: >-
    {% set h, t = states(reference_humidity_sensor)|float, states(reference_temperature_sensor) %}
    {% if not h or t == 'unknown' -%}
      'unknown'
    {%- else %}
    {% set t = t | float %}
    {{ (h*6.112*2.1674*e**((t*17.67)/(t+243.5))/(t+273.15))|round(2) }}
    {% endif %}

  abs_humid: >-
    {% set h, t = states(humidity_sensor)|float, states(temperature_sensor) %}
    {% if not h or t == 'unknown' -%}
      'unknown'
    {%- else %}
    {% set t = t | float %}
    {{ (h*6.112*2.1674*e**((t*17.67)/(t+243.5))/(t+273.15))|round(2) }}
    {% endif %}
  difference: "{{ abs_humid|float - abs_humid_ref|float }}"
  mode:
    "{% if switch_state == 'off' and difference|float > rising_threshold|float and block_state =='off'
    %}on{% elif switch_state == 'on' and difference|float > falling_threshold|float and block_state =='off'
    %}on{% else %}off{% endif %}"
mode: single
3 Likes

why is light reference a switch and not a light domain?