Meguro is one 600 m² office floor — four perimeter rooms of 150 m² — served by a variable-refrigerant-flow system: four 14 kW indoor units on one 56 kW (20 HP) outdoor unit, sharing a single suction line and a single liquid line. Four times fourteen on fifty-six is a connection ratio of 100 %, which is where ISO 15042 and AHRI 1230 rate a multi-split and where this outdoor unit is validated against a maker's own published capacity grid. Each indoor unit serves its own room and modulates to it; the outdoor unit is asked for the sum of what they take, at the coldest evaporating temperature any of them settled at, and its capacity is shared out by what each room is asking for that hour.

On Tokyo's year the four coils do 49.3 MWh of cooling and 26.5 MWh of heating for 11.3 MWh at the outdoor unit plus 4.2 MWh of indoor fans — about 26 kWh/m² a year for both jobs, which is what a VRF is bought for. Heating is the same machine run backwards: the indoor coils condense into their rooms while the outdoor coil takes the heat out of the weather and pays the defrost penalty for it.

The interesting hour is the one where the rooms disagree — a winter morning with the sun on the east and south rooms while the north and west still want heat — because a two-pipe machine cannot do both at once: the model picks the direction the whole manifold's demand asks for and the disagreeing rooms wait. Each room declares which way its glazing faces — 5 m² a room, the prototype's equal glazing on every façade — and on Tokyo's year the north and west rooms wait 129 and 126 hours for heat while the east and south shed sun, and the east room waits 112 hours for cooling when the vote goes the other way. Declared three-pipe, the same outdoor unit serves both directions on 163 hours and the waiting rooms read 1 unmet heating hour each and the east room 52 unmet cooling hours, for the same electricity — the recovered loads are 167 kWh a year, so what recovery buys this office is comfort, not energy. The rooms that disagree by kilowatts are in the Lookout Ridge clinic; the example ships two-pipe, which is the common machine.

What it reads on Tokyo

Coil duty	49.3 MWh cooling / 26.5 MWh heating
Electricity	11.3 MWh at the outdoor unit + 4.2 MWh of indoor fans — about 26 kWh/m² a year
Rooms	17.2–28.9 °C; unmet heating 129 north / 126 west, unmet cooling 112 east / 42 south (two-pipe) — 1 / 1 and 52 / 6 declared three-pipe
Humidity	2 950–3 130 hours a year above 0.012 kg/kg — a VRF without a dedicated outside-air unit does not control it
Connection ratio	100 % (4 × 14 kW on 56 kW), the ratio the standards rate at

What it taught

• A two-pipe manifold has one direction an hour, and the rooms that want the other wait — here the north and west rooms, 129 and 126 hours a winter, while the sunward rooms shed sun; three-pipe recovery buys those hours for no electricity, and the clinic is where it buys kilowatt-hours.
• An indoor unit cannot be offered more than it is rated for: alone on a machine four times its size, a 14 kW unit was offered all 85 kW of it, and a duty a coil cannot pass runs its condensing temperature off the chart.
• A VRF indoor unit has no reheat, so declaring a room humidity ceiling only makes it over-cool: the same building with the ceiling does 91.5 MWh of coil duty on 17.1 MWh at the outdoor unit against 49.3 and 11.3 without, and buys 9 % of its humid hours for it.

The machines

• VRF outdoor unit, 56 kW (20 HP) — open in the builder
• VRF indoor unit, 14 kW — open in the builder

Sources

• ISO 15042:2011 §6.1.1.2 and ANSI/CAN/AHRI 1230 §6.2.2.1.2 (multi-split rating at unity connection)
• DOE Commercial Prototype Building Models, Medium Office (occupancy, setback, gain densities)
• PVGIS TMY, Tokyo

Readings of the shipped model on the building's own PVGIS typical meteorological year; engineering estimates from catalog data and published correlations. The building runs on every plan, including Free, a few times a day.