Ventilation Assistant is a Home Assistant custom integration for HACS. It creates virtual ventilation devices from existing indoor sensors, outdoor sensors, and door/window contacts.

Model

The integration is fully configurable from the Home Assistant UI. Configuration is stored by Home Assistant as config entries in .storage/core.config_entries; it does not create Home Assistant Helpers.

Use the config flow to create:

  • one global defaults entry for the shared comfort temperature band, comfort relative-humidity band, and decision priority
  • one or more ventilation device subentries under that entry

priority can be TEMPERATURE or HUMIDITY. Each device can override any global default, or leave that field empty to inherit the global setting.

Each ventilation device creates a Home Assistant device containing:

  • Indoor temperature average
  • Indoor relative humidity average
  • Indoor absolute humidity
  • Indoor projected absolute humidity
  • Indoor projected relative humidity
  • Indoor projected relative-humidity difference
  • Indoor projected temperature difference
  • Outdoor temperature average
  • Outdoor relative humidity average
  • Outdoor absolute humidity
  • Any doors/windows open
  • Door/window open percentage
  • Temperature advice: KEEP_CLOSED, OPEN, KEEP_OPEN, or CLOSE
  • Humidity advice: KEEP_CLOSED, OPEN, KEEP_OPEN, or CLOSE
  • Advice: KEEP_CLOSED, OPEN, KEEP_OPEN, or CLOSE

Availability

Calculated entities return unavailable when their required inputs are missing or unavailable:

  • Averages require at least one available source entity.
  • Absolute humidity requires temperature and relative humidity.
  • Projected indoor absolute humidity requires indoor temperature and outdoor absolute humidity.
  • Projected indoor relative humidity requires indoor temperature and projected absolute humidity.
  • Door/window sensors require at least one available contact sensor.
  • Advice requires either available indoor/outdoor temperature values or available indoor/projected relative-humidity values. Without an available contact sensor, advice is limited to OPEN or CLOSE.

HACS installation during development

Copy or symlink this repository into Home Assistant, or add it as a HACS custom repository with category Integration. After installing, restart Home Assistant and add Ventilation Assistant from Settings > Devices & services.

Complete the global defaults form during first setup. After that, use Add device to add each ventilation device directly. Use the gear icon on the Ventilation Assistant integration entry to change the global defaults later. Use the configure action on a ventilation device subentry to change the input entities for that virtual device.