🌿 Overview

The SCD41-2HA module measures CO₂ (carbon dioxide) is designed for direct integration into Home Assistant using the ESPHome integration.

It is based on the professional-grade Sensirion SCD41 sensor, a high-precision photoacoustic NDIR CO₂ sensor well suited for indoor air quality monitoring.

The SCD41-2HA module comes fully assembled in a compact 56 × 58 × 28 mm enclosure and requires no hardware configuration.

⚙️ Technical Specifications

Sensor: Sensirion SCD41

Technology: Photoacoustic NDIR

CO₂ Measurement Range: 400 to 5000 ppm

CO₂ Accuracy: ±50 ppm – ±2.5% of measured value

Additional Measurements:

Relative humidity

Temperature

Connectivity: Wi-Fi

Integration: Native Home Assistant support via ESPHome integration

Power Supply: 5 V via USB Type-C connector

⚠️ The temperature reading is for indication only, as the sensor is affected by internal heat buildup.

🏠 Home Assistant Integration

Installation steps:

Plug the module into a 5 V USB-C power supply.

Connect it to your Wi-Fi network.

It will be automatically detected, or you you will need to add it via the ESPHome integration.

The CO₂, humidity, and temperature entities will appear automatically in Home Assistant.

🧰 Typical Use Cases

Indoor air quality monitoring

Automating ventilation or air purifiers based on CO₂ levels

Displaying live air quality data on Home Assistant dashboards

💡 Extensions and Options

In addition to CO₂ measurement, you may also find it useful to monitor:

VOC and NOx with the SGP40 sensor

Temperature, humidity, and pressure with the combined AHT20 + BMP280 sensor

A BH1750 light sensor, although this is less relevant for air quality

These are available as optional add-ons.

If you’d like to integrate additional sensors or features (such as a buzzer, button, or LEDs), feel free to contact me.

🔗 Related Product

If you also wish to measure fine particulate matter (PM), check out my SPS30-2HA module here: 👉 SPS30-2HA