Delta ERV (台達全熱交換機) Integration for Home Assistant

This is a custom component for Home Assistant that integrates Delta ERV (Energy Recovery Ventilation) devices via Modbus (serial or TCP). You need to connect a RS485 to Ethernet/Wi-Fi converter to the RS485 port of the Delta ERV system.

Features

• Control ERV fan speed (Low/Medium/High)
• Turn ERV system on/off
• Monitor outdoor and indoor return temperatures
• Monitor supply and exhaust fan speeds
• Monitor system status and error conditions
• Support for both serial RS485 and TCP connections

Supported Models

Based on the Delta ERV specification document, this integration supports:

• VEB250-N, VEB150, VEB250, VEB350 models (full feature support)
• VEB500, VEB800, VEB1000 models (limited register support)

Note: Some sensors may show as "unavailable" depending on your ERV model. This is normal as different models support different registers. The core fan control functionality (power and speed) is supported on all models.

Installation

1. Copy the custom_components/delta_erv directory to your Home Assistant custom_components directory.
2. Restart Home Assistant.
3. Add the integration through the Home Assistant UI (Configuration > Integrations > Add Integration).

Configuration

The integration can be configured through the Home Assistant UI. You'll need to provide:

• Name: A friendly name for your ERV device
• Connection Type: Choose between Serial, TCP, or RTU over TCP
• For Serial connections:
  • Port: Serial port (e.g., /dev/ttyUSB0)
  • Slave ID: Modbus slave ID (1-247, default: 100/0x64)
  • Optional: Baud rate, data bits, parity, stop bits
• For TCP connections:
  • Host: IP address of the Modbus TCP gateway
  • Port: TCP port (default: 502)
  • Slave ID: Modbus slave ID (1-247, default: 100/0x64)

Entities

Fan Entity

• ERV Fan: Controls the main ERV fan with three speed levels
  • Low (風量 1)
  • Medium (風量 2)
  • High (風量 3)

Sensor Entities

• Outdoor Temperature: External air temperature
• Indoor Return Temperature: Return air temperature
• Supply Fan Speed: Supply fan RPM
• Exhaust Fan Speed: Exhaust fan RPM
• Abnormal Status: System error conditions
• System Status: Current system operating state

Register Mapping

The integration uses the following Modbus registers based on the Delta ERV specification:

Register	Name	Function
0x05	開關機	Power On/Off
0x06	風量設定	Fan Speed Setting
0x10	異常狀態	Abnormal Status
0x11	外氣溫度	Outdoor Temperature
0x12	室內回風溫度	Indoor Return Temperature
0x0D	送風機轉速	Supply Fan Speed
0x0E	排風機轉速	Exhaust Fan Speed
0x13	系統狀態	System Status

Hardware Setup

1. Connect your Delta ERV system to a RS485 to Ethernet/Wi-Fi converter
2. Configure the converter for the appropriate baud rate (default: 9600)
3. Set the ERV Modbus slave ID (default: 100)
4. Connect the converter to your network

Troubleshooting

Connection Issues

• Verify RS485 wiring (A/B or +/- connections)
• Check baud rate and communication parameters
• Ensure the slave ID matches between the ERV and configuration
• Test with a Modbus testing tool first

Missing Entities

• Some registers may not be available on all ERV models
• Check the specification document for your specific model
• Enable debug logging to see communication details

Debug Logging

Add this to your configuration.yaml to enable debug logging:

logger:
  logs:
    custom_components.delta_erv: debug

Development

This integration is based on the Delta ERV Modbus specification document and follows Home Assistant integration best practices.

License

This project is licensed under the MIT License.