Aqara Temperature / Humidity sensitivity with ZHA

thimic · June 22, 2020, 12:07pm

Hi,

Wondered if anyone’s got experience adjusting the sensitivity of the Aqara Temperature / Humidity sensor.

I am using the humidity reading to turn on a bathroom fan when the humidity is high and off again when it drops. It works okay most of the time, but quite often there’ll be a really long gap (up to almost an hour) between two readings. This despite the humidity definitely changing significantly over the period.

The fan usually kicks in when it’s supposed to. The issue is having it turn off. I’m guessing that’s because the rise in humidity usually has a much steeper slope than the drop off.

I’m using a ConBee II and ZHA. There’s a tolerance attribute under RelativeHumidityCluster, though I can’t seem to get a reading of the current tolerance, even when repeatedly pressing the button on the side to keep the sensor alive. I also don’t know what tolerance values to try instead or the manufacturer code, if that is needed.

Thanks,
Michael

lolouk44 · June 22, 2020, 4:12pm

I don’t believe you can adjust the sensitivity on the sensor.
Are you sure however that the issue is sensitivity? What happens when you press the button (don’t hold), do you see an update in HA?
I experience something a bit similar with similar setup (aqara hygro sensor via zigbee2mqtt and a sonoff basic switch connected to the fan)
The way I switch my fan off however is if R% is below 75% for over 20min:

github.com

lolouk44/homeassistant/blob/1443afd02b82e63477172d8fc833a941d05e98fc/automation/Bathroom.yaml

- alias: Bathroom - Turn Fan On When R% > 75%
  id: bathroom_-_turn_fan_on_when_r_over_75
  initial_state: true
  trigger:
    - platform: state
      entity_id: sensor.bathroom_humidity
  condition:
    - condition: template
      value_template: '{{ states("sensor.bathroom_humidity") | int > 75 }}'
    - condition: state
      entity_id: switch.bathroom_fan
      state: 'off'
  action:
  - service: switch.turn_on
    data:
      entity_id: switch.bathroom_fan

- alias: Bathroom - Turn Fan Off When R% < 75%
  id: bathroom_-_turn_fan_off_when_r_under_75
  initial_state: true

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thimic · June 23, 2020, 7:04am

This is how I’ve solved it too for now. In our case the fan turns off 12 minutes after the last above threshold reading. That works reasonably well most of the time but it does mean the fan staying on longer than we’d like sometimes, while going off too early at others.

It’s winter in our part of the world at the moment, and the air the fan brings in is rather cold. That’s why having the fan stay on longer than necessary is a bit of a big deal, at least for my wife

I’ll try to press the button next time there’s a long interval between updates and see if that forces an update.