2026.6.3
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Set pollution settings

The Set pollution settings action configures how your Renson ventilation unit responds to pollution. You set the ventilation levels used during the day and night, choose which sensors trigger extra ventilation, and tune the CO2 thresholds.

This is useful when you want an automation to change how aggressively the unit ventilates, for example a quieter program at night.

Targets of the action

This action requires a target. The target is the object of the action. You can point the action at a single entityAn entity represents a sensor, actor, or function in Home Assistant. Entities are used to monitor physical properties or to control other entities. An entity is usually part of a device or a service. [Learn more], a device, an area, a floor, or a label, and Home Assistant will run the action on every matching fan entity behind that target.

  • Entity: one specific fan entity, such as fan.living_room.
  • Device: every fan entity that belongs to a device.
  • Area: every fan entity in a room or area.
  • Floor: every fan entity on a floor.
  • Label: every fan entity that shares a label.

You can also select different target types in one action. For example, you can add a specific entity and an area as targets in the same action to run the action on both of them at once.

Using this action from the user interface

If you prefer building automations and scripts visually, Home Assistant walks you through this action step by step. You pick what to target, tweak a few options, and save. No YAML knowledge required.

To configure the pollution settings from an automation or a script:

  1. Go to Settings > Automations & scenes.
  2. Open an existing automation or script, or select Create automation > Create new automation.
  3. If you’re setting up a new automation, add a trigger in the When section. Scripts don’t need a trigger. They run when something else calls them.
  4. In the Then do section, select Add action.
  5. Select what you want to control. Under By target (see Targets), select the Renson ventilation unit.
  6. From the actions shown for that target, select Renson: Set pollution settings.
  7. Set the Day pollution level and Night pollution level, then adjust the control and CO2 options as needed.
  8. Select Save.

Options in the UI

Day pollution level (Required)

The ventilation level used when pollution is detected during the day. One of: Level 1, Level 2, Level 3, or Level 4.
Night pollution level (Required)

The ventilation level used when pollution is detected during the night. One of: Level 1, Level 2, Level 3, or Level 4.
Enable humidity control (Optional)

Whether the unit increases ventilation when it detects high humidity.
Enable air quality control (Optional)

Whether the unit increases ventilation when it detects poor air quality.
Enable CO2 control (Optional)

Whether the unit increases ventilation when it detects high CO2 levels.
CO2 threshold (Optional)

The CO2 level, in parts per million, above which the unit increases ventilation, between 400 and 2000.
CO2 hysteresis (Optional)

How far the CO2 level, in parts per million, must drop below the threshold before ventilation returns to normal, between 50 and 400.

Using this action in YAML

If you work directly in YAML, or you want to know exactly what Home Assistant does under the hood, this section has the technical reference. It lists the field names you use in YAML, their types, and which ones are required.

In YAML, refer to this action as renson.set_pollution_settings. A basic example looks like this:

ActionActions are used in several places in Home Assistant. As part of a script or automation, actions define what is going to happen once a trigger is activated. In scripts, an action is called *sequence*. [Learn more] 
action: renson.set_pollution_settings
target:
  entity_id: fan.ventilation
data:
  day_pollution_level: level3
  night_pollution_level: level2

This sets the day ventilation level to level 3 and the night ventilation level to level 2.

Options in YAML

day_pollution_level string Required

The ventilation level used when pollution is detected during the day. One of level1, level2, level3, or level4.

night_pollution_level string Required

The ventilation level used when pollution is detected during the night. One of level1, level2, level3, or level4.

humidity_control boolean

Whether the unit increases ventilation when it detects high humidity.

airquality_control boolean

Whether the unit increases ventilation when it detects poor air quality.

co2_control boolean

Whether the unit increases ventilation when it detects high CO2 levels.

co2_threshold integer

The CO2 level, in parts per million, above which the unit increases ventilation, between 400 and 2000.

co2_hysteresis integer

How far the CO2 level, in parts per million, must drop below the threshold before ventilation returns to normal, between 50 and 400.

Try it yourself

Ready to test this? Open Developer tools > Actions, search for this action, fill in the fields, and select Perform action. You see what happens on your actual entitiesAn entity represents a sensor, actor, or function in Home Assistant. Entities are used to monitor physical properties or to control other entities. An entity is usually part of a device or a service. [Learn more] without writing a line of YAML.

More examples

Real scenarios where this action shows up in automations and scripts. Copy any example and adapt it to your setup.

Tip

You don’t need to edit YAML to use these examples. Copy a YAML snippet from this page, open the automation editor in Home Assistant, and press Ctrl+V (or Cmd+V on Mac). Home Assistant automatically converts the pasted YAML into the visual editor format, whether it’s a full automation, a single trigger, a condition, or an action.

Automation: Use a quieter program at night

This automation lowers the night pollution ventilation level every evening so the unit runs more quietly while you sleep.

  • Trigger: the time is 10:00 PM
  • Action: Renson: Set pollution settings
    • Target: the ventilation unit
    • Day pollution level: level3
    • Night pollution level: level1
Show example YAML
AutomationAutomations in Home Assistant allow you to automatically respond to things that happen in and around your home. [Learn more] 
alias: "Quieter ventilation at night"
triggers:
  - trigger: time
    at: "22:00:00"
actions:
  - action: renson.set_pollution_settings
    target:
      entity_id: fan.ventilation
    data:
      day_pollution_level: level3
      night_pollution_level: level1

Still stuck?

The Home Assistant community is quick to help: join Discord for real-time chat, post on the community forum with the action you’re calling and what you expected to happen, or share on our subreddit /r/homeassistant.

Tip

AI assistants like ChatGPT or Claude can also explain actions or suggest the right one when you describe what you want in plain language.

Related actions

These actions work well alongside this one:

  • Set timer: Runs the Renson ventilation unit at a chosen level for a set time.

  • Set Breeze: Configures the Breeze function of the Renson ventilation unit.