I needed a proper roof ventilation to cool my server room. Noice (dB) and power usage are the most important factors for me. I tested many options and finally bought a Zehnder/StorkAir MX110 Fan.Zehnder/StorkAir MX110 Roof Fan
This fan is really quiet, has low power usage and you can buy these quite cheap at online auctions, marketplaces or Ebay (around €150-250).
New price is about € 1000,- or even more, depends on the exact model.

Since I want to control it using my own domotics (via KNX, Datec 0-10v Analog Actor based on a temp. sensor), I could grab any model since they all have the same hardware. Other models (MX110 ZMV, WS,..) add a pressure sensor, temperature control,..etc. which I don’t need.

The basic hardware let you control the fan in a lot of ways: on/off, voltage adjusted (0-10v), RS485,..
Zehnder/StorkAir MX110 without cover to see Control Unit

Below I link all relevant information and software because the people at Zehnder were not always as helpful as you might expect.

No Buy a $4,- Passive RS232 to RS485 convertor (A passive one doesn’t need an additional 5-12V, you can recognize it because it has only 3 connectors: RS-485+, RS-485- and GND).

Passive RS-232 to RS-485 Converter

Connect the RS485+ to pin … on the MX control unit.
Connect the RS485- to pin … on the MX control unit.

Below is the pinout of the MX Controller (click to enlarge)

Zehnder StorkAir MX Fan Control Unit Pinout


Question I still have is:
– Does someone know the password to get into ‘Service mode’ ?

Maintenance Software Request for Login

A screenshot of the Maintenance Software with one MX110 connected (click to enlarge)
Zehnder/StorkAir Maintenance Software screebshot