Can a single-zone mini split be used with multiple indoor units?Updated 6 hours ago

No. If multiple zones (indoor units) are needed, you must purchase a multi-zone system. The selection, which is up to the buyer, is dependent on the number of distinct zones and layout of the dwelling.

Single-zone systems have 1 set of valves for attaching 1 lineset and 1 indoor unit.

The unit has 1 set of valves (suction+liquid) for supporting one connected indoor unit

Multi-zone systems have multiple sets of valves for attaching multiple linesets and indoor units.

The multi-zone outside condenser unit has multiple sets of valves for connecting more than 1 lineset and indoor air handler units

In a multi-zone configuration, the indoor air handlers connect independently to the main outdoor condensing unit via its own set of refrigerant lines and control cable. This is why a single-zone outside unit cannot accommodate additional indoor units.