When only one room or small zone requires cooling, a properly designed zoning system should not continue delivering full-system airflow to that single zone.

The active zone damper remains open according to demand, while satisfied zones reduce their airflow.

What happens to the indoor fan?

An ECM or variable-speed fan can reduce airflow as the number of active zones decreases.

The control system may also use duct static-pressure feedback to prevent excessive pressure when several dampers close.

Can every other damper completely close?

Not always. The air handler still requires a minimum amount of airflow to operate safely and correctly.

Depending on the system, some zones may retain a minimum damper opening, or other airflow-management strategies may be used.

What happens to inverter compressor capacity?

As the overall building cooling demand decreases, the inverter heat pump can reduce compressor output according to return-air temperature, coil conditions and its internal control logic.