Adding numbers with template sensor

Configuration
1

I am automating my bathroom vent fan, I’m planning to compare my house average humidity against the bathroom humidity for an on/off threshold. Problem is my bathroom is very consistently ~10% higher humidity than the rest of the house. So I need to add ~10-15% onto the average for a setpoint for controlling the fan. From my google fu it looks like I need a template sensor, but I’m at a complete loss for how to make this happen after reading through the documentation, am I even on the right track using a template sensor? I’ve done a few templates (binary trend sensor, and 2 switches) before but those are obviously different.

2

Yes, you’re on the right track. Let us know what entities you have for your sensors to save us having to make too much stuff up.

3

Well my house average and bathroom humidity sensors are :

sensor.house_humidity_minus_bathroom
sensor.bathroom_temp_humid_humidity
4 
template:
  - binary_sensor:
      - name: Bathroom too humid
        state: >
          {{ states("sensor.bathroom_temp_humid_humidity")|float(0) > states("sensor.house_humidity_minus_bathroom")|float(0) * 1.1 }}

Make sure you only have one top-level template: declaration.

That will be 'on' if the bathroom humidity is more than 10% over the house average. Of course, if the house average is over 91%, it’ll never come on.

1 Like
5

I think that will work! And I’m not concerned about the house hitting 91%, we very rarely get those conditions and we are adding a heat pump (as soon as the hardware arrives) which will lower the humidity further.