Daikin's current residential Multi range includes outdoor units capable of serving up to five indoor units. The maximum number is not the only design consideration: each combination must comply with the selected outdoor unit's permitted connected capacity, indoor-unit combinations, pipe lengths, vertical separation and other manufacturer limits. We therefore design the system room by room and then select the appropriate outdoor unit rather than choosing a five-port unit simply because five rooms exist.

Each indoor unit has its own controller and can normally be switched on or off and set to its own target temperature. That gives much better room-by-room control than treating the house as one zone. However, the indoor units share an outdoor system, so the overall operating mode and available capacity are governed by the particular multi-split design. We explain the controls and any system-wide limitations at design and handover.

Do not assume this is possible on a standard residential multi-split. Many conventional multi-split systems operate the connected indoor units in the same overall mode, so one room cannot call for heating while another simultaneously calls for cooling. If simultaneous heating and cooling is a genuine project requirement, it needs to be identified at survey and a system specifically capable of that function would need to be considered.

Not automatically. Multi-split is attractive where several rooms need AC but the customer wants fewer outdoor units, has limited external space or wants a cleaner exterior. Separate single splits can sometimes offer simpler pipework, greater redundancy and different design flexibility. The best solution depends on room loads, available outdoor positions, pipe routes, aesthetics, budget and how the rooms will be used. We compare the practical options rather than defaulting to one approach.

Each indoor unit requires insulated refrigeration pipework back to the relevant outdoor system, together with condensate drainage and the required interconnection/control cabling. Routes may pass through lofts, cupboards, risers, ceiling voids or external containment depending on the property. We aim for gravity condensate drainage wherever practical and minimise visible containment. On refurbishment projects, first fixing before plastering and decorating can produce a much cleaner finished installation.

Potentially, and flat roofs are common locations on London extensions, but the position must be designed properly. We consider roof structure and waterproofing, mounting feet or support frame, vibration, airflow clearances, service access, edge protection/access arrangements, pipe length, electrical isolation, noise and planning. Planning rules can be particularly relevant to roof-mounted heat-pump/AC equipment, so the location should be checked before installation rather than assumed to be permitted.

The other connected indoor units can normally continue operating within the capabilities of the selected multi-split system. Inverter-driven equipment adjusts output according to the active demand, although exact minimum/maximum capacities and efficiency vary by outdoor-unit model and combination. This is one reason the system must be selected using manufacturer data rather than treating the outdoor unit as a fixed-capacity box.

Yes, and this is often the best time to install a multi-room system. We can agree indoor/outdoor positions and then install the refrigeration pipes, condensate drains, interconnections, electrical supplies and required penetrations before walls and ceilings are closed. We return later for second fix, equipment installation and commissioning. Early coordination with the builder also helps avoid clashes with steelwork, joinery, lighting, plumbing and other services.

We use the electrical data for the actual selected outdoor/indoor combination and assess the existing installation before specifying the circuit. Our electricians consider design current, manufacturer protective-device requirements, cable size and route, voltage drop, isolation, RCD/RCBO requirements, earthing and the property's maximum demand. We also consider other significant loads such as EV charging, battery systems and heat pumps so the AC is not designed in isolation.