If airflow is excessive in all zones despite having all the dampers open, proceed as follows.
Check the AC unit's speed controls. To do so:
1. Open all the dampers in the Airzone system, generating demand in all the zones.
2. Disconnect the main control board's communication gateway with the air conditioning unit. Thus, the AC unit's controller will allow changes to be made to the speeds. After a minute, the Airzone thermostats will display Error 9.
3. Check that the speeds change properly using the AC unit's controller.

If you cannot change the AC unit's speeds, there is a problem in the AC unit's speed controls. Consult the manufacturer about the problem.

If you can control the speeds, lower the speed until an airflow is attained in all zones which is not excessive.

If the airflow continues to be excessively high even at the lowest speed, contact our Technical Department (Open a new ticket).

If a suitable airflow is achieved by lowering the speed, reconnect the AC unit gateway and set the Q-Adapt parameter to the desired airflow rate (How do I set Q-Adapt?).

You should also check that the gateway's speed settings are correct (How do I control the AC unit's speeds?).