Set fan timer

The Set fan timer action sets the fan to run for a specific duration. The SDM API supports a maximum duration of 12 hours.

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 set the fan timer 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. From the search box, search for and select Nest: Set fan timer.
6. Select what you want to control. Under By target (see Targets), pick the area your thermostat is in. You can also select a device or a specific entity.
7. Set the duration for the fan to run.
8. Select Save.

Options in the UI

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 nest.set_fan_timer. A basic example looks like this:

action: nest.set_fan_timer
target:
  entity_id: climate.upstairs
data:
  duration:
    minutes: 15

This sets the upstairs thermostat fan to run for 15 minutes.

Options in YAML

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 nest entity behind that target.

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

Good to know

• The SDM API supports a maximum duration of 12 hours.

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.

Automation: ventilate when CO2 levels are high

When a CO2 sensor crosses a threshold, run the fan to bring in fresh air until levels drop back to normal.

• Trigger: Numeric state: CO2 sensor above 1000 ppm
• Action: Nest: Set fan timer
  • Target: Living room thermostat
  • Duration: 30 minutes

alias: "Run fan when CO2 is high"
triggers:
  - trigger: numeric_state
    entity_id: sensor.living_room_co2
    above: 1000
actions:
  - action: nest.set_fan_timer
    target:
      entity_id: climate.living_room
    data:
      duration:
        minutes: 30

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.