Published on · By the Faster-EV team
Single-split: one room, one outdoor unit
A single-split pairs one indoor unit with one outdoor unit. It is the simplest solution for a single room: quick installation, independent operation and a wide choice of wall-mounted or console units.
For several rooms, multiplying single-splits also multiplies the outdoor units on the facade or balcony.
Multi-split: several rooms on one outdoor unit
A multi-split connects several indoor units, usually two to five, to a single outdoor unit. Each room keeps its own unit and set temperature, with only one unit outside.
The trade-offs: all units run in the same mode (heating or cooling) at the same time, an outdoor unit failure affects every room, and each indoor unit needs its own refrigerant line, often protected by trunking.
Ducted: a single, invisible unit
A ducted unit is installed in the attic or a false ceiling: air is distributed through ducts to grilles in each room. Only the grilles remain visible, making it the most discreet solution for a whole home.
Combined with a multi-zone system, which adds motorised dampers and a thermostat in each room, it lets you control each room separately. It does, however, need space for the unit and the ducts, which makes it best suited to new builds or major renovations.
How to decide
One room to equip: a single-split is the simplest. Two to five rooms with wall space for the units: a multi-split limits the number of outdoor units. The whole home, with discretion in mind and space in the attic or a false ceiling: a ducted unit with multi-zone control.
For offices, shops or buildings, commercial ranges (cassettes, ceiling-suspended and ducted units) and VRF systems meet larger needs.
Accessories to plan for
Whatever the system, plan for refrigerant lines between the units, trunking to protect them on the facade, condensate drainage (with a condensate pump if gravity drainage is not possible) and wall or floor supports for the outdoor unit. Connection and commissioning must be carried out by a company holding a refrigerant handling certificate.