Mitsubishi Electric installer, Melbourne’s south-east.

The 2.5 kW MSZ-AP is the bedroom unit. Quiet at 21 dBA on low fan, barely draws anything on standby, and the parts pipeline is never a worry. If it's going in a kid's room and it has to run all night without waking anyone, this is the one.

The 3.5 kW is the sweet spot for a big master bedroom or a smaller open-plan. Same reliability as the 2.5, same low-noise profile, just enough extra capacity to handle the doors-open scenario without running at 100% all summer.

The 5.0 kW MSZ-AP is our default recommendation for an open-plan living zone in a modern brick-veneer family home. Big enough to handle a Melbourne heatwave with the doors open, small enough that it doesn't cycle constantly on a mild day.

The 6.0 is for the room that falls between the two obvious sizes. Cathedral ceilings, or a big north-facing glass wall, add load that a floor-area calculation misses, and that's usually what pushes a room off the 5.0 and onto this one.

The 7.1 is about as far as a wall unit sensibly goes. Past this, ducted or multi-head moves air around a room better than one head can. For a big north-facing living zone in Berwick or Officer, this is usually the answer.

The biggest wall split Mitsubishi makes. In most rooms this size, ducting moves the air better. Where this one wins is the single large space you don't want to duct: a warehouse conversion, a double-height room, anywhere the ceiling turns ductwork into a project of its own.

One outdoor condenser, two indoor heads. This is the answer when there's exactly one place the outdoor unit can go, a balcony or a narrow side path, and you still want the two rooms controlled separately.

The 3F is our most-installed multi-head. One outdoor unit, three bedrooms, which is a lot tidier on the wall than three separate condensers, and each room gets its own controller rather than sharing a ducted zone with the room next door.

The 4F is our recommendation for a family home that wants individual per-room setpoints rather than shared ducted zones. One outdoor unit, four indoor heads, one refrigerant loop to service.

The 5F handles five indoor heads off one outdoor unit, 4 bedrooms plus a living zone. Beyond this we move to the 6-port MXZ-6C or to ducted.

The MXZ-6C is Mitsubishi's biggest multi-head, 12 kW across 6 indoor heads off one outdoor unit. Genuinely rare in the market (most brands cap at 5 heads). What we quote for a 5-6 bed home that wants proper per-room control without committing to ducted.

The PEA-M is Mitsubishi's default ducted system for a typical Melbourne family home. Three capacity steps (10 / 12.5 / 14 kW) cover most single-storey retrofits, and the HAA-VKA Hyper Heating variant holds capacity down to −15 °C, worth specifying for hills postcodes like Emerald and Gembrook. Pairs with the PUZ outdoor and any Zonemate zone controller.

The PEA-M160/180/200 is the large-capacity extension of the PEA-M range, same indoor platform as the M100/125/140, sized up for double-storey homes, 6+ zones, or long ceiling-cavity duct runs. The 20 kW step is offered in both single-phase and three-phase to suit whatever supply the property has. Pairs with the PUZ-M outdoor and the HAA-VKA Hyper Heating variant is available up to M140 for hills postcodes; larger capacities use the standard PUZ.

The MFZ-KW sits on the floor where an old radiator sat. It's the answer when there's no wall free at head height, when warmth coming off the floor suits the room better than warmth coming off the ceiling, or when you're dropping into an old hydronic radiator's footprint and don't want walls patched up high. Same reliability as the wall splits underneath the different shape.

The PAR-41MAA is Mitsubishi's current-generation standard wired wall controller, the model we fit as standard on every PEA-M and MFZ-KW install. Physical wall control for anyone who'd rather not reach for a phone or handheld remote. Direct interface into Zonemate zoning so one controller drives both temp and zones.

The PAR-ZC01M-E is the glass touch controller on the wall, and behind it sits a PAC-ZC interface board driving the dampers: PAC-ZC40 for four zones, PAC-ZC80 for eight, in an L version for 24 V damper motors and an H version for 240 V. The part people notice is the occupancy sensor built into the controller itself. It watches the room it is in, and when nobody has been there for a while the system can drop that zone back rather than keep conditioning an empty study. Everything is Mitsubishi end to end, which means one warranty channel and one support number for the indoor unit, the outdoor unit and the zoning. Zonemate goes on instead when a job wants more than eight zones, or more than one indoor unit driven from a single tablet. Both are on the van.