Did you consider Airthings devices? Not exactly zigbee, but they might be able to monitor CO2, VOCs, PM2.5 and Radon (no gas). There is an app for integration in HPM
Did you consider Airthings devices? Not exactly zigbee, but they might be able to monitor CO2, VOCs, PM2.5 and Radon (no gas). There is an app for integration in HPM