What is a multi-split air conditioning system?

A multi-split system (also called a multi-zone or ductless multi-split) connects multiple indoor units to one outdoor condensing unit via refrigerant lines. Unlike a single-split system which serves one room, a multi-split lets you cool or heat two, three, or more separate spaces from a single outdoor compressor.

Each indoor unit operates independently, meaning you can set different temperatures in the bedroom, living room, and kitchen without ducting. Refrigerant flows from the outdoor unit through insulated piping to each indoor evaporator, which are typically mounted on walls or ceilings. A wireless or wired remote controller on each unit lets occupants adjust their zone without affecting other rooms.

This setup appeals to older HDB flats and landed homes in Tampines where central air conditioning ductwork is impractical or costly to install. Multi-split systems avoid the space and structural disruption of ductwork, and spare unused rooms from air conditioning, reducing energy draw. The trade-off is higher upfront cost than a single-split, more indoor units to maintain, and the need for proper lineset routing and refrigerant charge during installation.

When selecting a multi-split, work with air conditioning installation providers who size the outdoor unit correctly to the combined load of all indoor units and ensure proper lineset installation, as undersized or incorrectly configured systems lose efficiency.