If the louvres increase the amount of outlet air, what happens to the return air louvres?

When the louvres that control the outlet air increase their opening, this typically results in an increase in the volume of air being discharged from the system. The return air louvres function by maintaining a balance in the air pressure and flow within the system. If more air is being pushed out of the outlet louvres, the return air louvres need to adjust to respond to this change.

In this case, having the outlet louvres open wider increases the pressure on the outgoing air, which can lead to a differential that causes the return louvres to close. Closing the return air louvres helps to prevent excessive loss of conditioned air from the system, ensuring that the overall airflow remains balanced and efficient. Consequently, they adjust in a manner that optimizes the system's performance and maintains the desired environmental conditions.