Using Temperature, Humidity and Atmospheric Pressure for some Greenhouse Calculating Stuff

Home Assistant template.yaml

{# Some stuff for testing Home Assistant Template to make template sensors  #}
{# This is equivalent to Tasmota Berry Script used on greenhouse automation #}
{# https://gist.github.com/boozeman/e191e01ef914e2651544a03a7acf32eb #}

{# Target_VPD set here by hand. Read some sensor data to variables  #}
{% set Target_VPD = 1.4 |float %}
{% set T = states('sensor.your_sensor_sht3x_temperature') |float %}
{% set RH = states('sensor.your_sensor_sht3x_humidity') |float %}
{% set p = states('sensor.your_sensor_bme280_seapressure') |float %}

{# Absolute Humidity g/m3 #}
{% set AH = RH * 6.112 * e**((17.67 * T) / (T + 243.5)) * 2.1674 / (273.15 + T) * p / 1013.25 %}

{# Saturation Vapour Pressure in kPa #}
{% set SVP = 610.78 * e**(T / (T + 237.3) * 17.2694) /1000 %}

{# Saturation Vapour Pressure but different equation in kPa #}
{% set es = 6.112 * e**((17.67 * T) / (T + 243.5)) /10  %}

{# Actual Vapour Pressure in kPa #}
{% set ea = RH/100 * es %}

{# Vapour Pressure Deficit calculated with 2 different ways in kPa #}
{# https://gardeningincanada.net/rapid-growth-from-houseplants/ #}
{% set VPD = es - ea %}
{% set VPD2 = SVP * (1 - RH/100) %}

{# How to get optimal relative humidity for choosed VPD value #}
{% set Target = SVP - Target_VPD   %}
{% set rh = (Target / es) * 100 %}

Temperature: {{ T }}
equivalent sealevel pressure: {{ p }} hPa
relative humidity: {{ RH }} %
Saturation vapour pressure: {{ es |round(3) }} kPa
Saturation vapour pressure2_ {{ SVP |round(3) }} kPa
Actual vapour pressure: {{ ea |round(3) }} kPa
Vapour pressure Deficit VPD {{ VPD |round(3)  }} kPa
VPD2: {{ VPD2 |round(3) }}
Absolute humidity:{{ AH |round(2) }} g/m3
Target humidity for VPD:{{ rh |round(1) }} %