Dew Point/Temperature Sensor, my configuration.yaml

Configuration
5

Hi there.

I liked this, but needed dew point calculations for various rooms. Turns out, the new macros syntax is pretty neat to make multiple template sensors with a macro function.

Here’s how it works on my side.

Step 1: Create a new folder custom_templates/ in your configuration folder, if it doesn’t exist already.

Step 2: Create a new file custom_templates/macros.jinja:

{% macro calculate_dew_point(entity_temperature, entity_humidity) %}
  {% set T, RH = states(entity_temperature), states(entity_humidity) %}
  {% if (T == 'unknown') or (RH == 'unknown') %}
    unknown
  {% elif (T == 'unavailable') or (RH == 'unavailable') %}
    unavailable
  {% else %}
    {% set T = T | float %}
    {% set RH = RH | float %}
    {% set a = 6.1121 | float %}
    {% set b = 18.678 | float %}
    {% set c = 257.14 | float %}
    {% set d = 234.5 | float %}
    {% set e = 2.71828 | float %}
    {% set gamma = log((RH/100)*e**((b-T/d)*(T/(c+T)))) | float %}
    {% set dew_point = ((c * gamma) / (b - gamma)) | round(1) %}
    {{ dew_point }}
  {% endif %}
{% endmacro %}

Step 3: Create your template sensors like this:

template:
  - sensor:
    - name: "Kitchen - Dew Point"
      unique_id: kitchen_dewpoint
      unit_of_measurement: "°C"
      icon: mdi:water-percent-alert
      state: >
        {% from 'macros.jinja' import calculate_dew_point %}      
        {{ calculate_dew_point('sensor.kitchen_temperature', 'sensor.kitchen_humidity') }}

P.S.: The P formula from the original code got removed in step 2, as it wasn’t used for the dew point result.

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