Smart Ventilation
A view into the air moving through your home. An ESPHome integration and a Home Assistant card bring the ventilation controller, temperatures and airflow into one place.
- Integration
- ESPHome + Home Assistant
- Connection
- Modbus / RS-485
- Tested controller
- Optima 251
Two parts, one system
The ESPHome gateway connects the ventilation controller to Home Assistant through its encrypted native API. A separate dashboard card uses Home Assistant entities to make the airflow and operating state easier to read.
The card can also display ventilation entities from other integrations. It needs no firmware changes and does not connect directly to a controller’s HTTP API.
From the controller to the dashboard
The integration exposes air temperatures, humidity, fan output percentages and connection diagnostics. It also provides controls for ventilation level, temperature setpoint and controller settings. State is read back through scheduled polling.
Airflow Card shows the outdoor-to-supply and extract-to-exhaust paths, recovery or bypass state, and optional diagnostics. Its buttons open Home Assistant’s entity details. The card itself does not send controller commands.
Tested hardware and current limits
The ESPHome configuration was developed and tested with a NIBE GV-HR 120-400, an Optima 251 controller and a Waveshare ESP32-S3-RS485-CAN gateway. The repository also identifies the regional ALTO Basic 120-400 product name.
Compatibility with other units or controllers has not been established. Bypass position and RPM mappings include documented assumptions. The card’s recovery estimate is a temperature ratio, not measured energy efficiency.
Installation and configuration
The ESPHome repository contains the configuration, setup instructions, wiring diagram and register documentation. The Airflow Card repository explains installation through HACS as a custom repository or as a manual dashboard resource.
Use those repositories for the current instructions and known limitations.