Connect your Zehnder ComfoAir 350

As a ventilation system a Zehnder ComfoAir 350 is in use.

Zehnder ComfoAir 350 assembled Zehnder ComfoAir 350 with serial cable

Connect the ventilation system

The ventilation system is connected with openHAB via a serial port which is normally used for the maintenance access. It is directly connected to the serial port of my server. Currently I can’t answer if it works with a “RS232 to ethernet lan adapter”. Just try and let me know if it works.

Since the communication protocol is very well documented by the community, you can use it for your own control software. I developed a binding for openHAB which allows me to control and analyse the ventilation system.

Ventilation visualisation and control in openHAB

Automation by rules

By openHAB rule engine following smarthome functions could be implemented.


The binding configuration and all openHAB rules to control the ventilation system are part of my deployment project and can be tried or downloaded there. Alternatively, the openHAB rules can also be obtained directly from my Github Repository.

Additional examples and informations