General Assist Technical Reference
R32 Multi Systems
Indoor unit combinations, connection capacities and installation limits
Applicable to New Zealand outdoor models AOTH24KBCA3, AOTH30KBTA4, AOTH36KBTA5 and AOTH45KBTA5
Fujitsu AIRSTAGE R32 Multi Systems allow between two and five individually controlled indoor units to be connected to one outdoor unit. The indoor unit quantity, capacity classes, model compatibility, piping ports and total connection capacity must all be checked before the equipment is selected or installed.
Important: Adding the indoor unit rated kW values is not sufficient to confirm compatibility. The proposed indoor units must form an exact approved capacity-class combination for the selected outdoor unit. Confirm the current technical manual before installation.
1. Outdoor unit quick reference
| Outdoor model | Indoor units | Cooling capacity | Heating capacity | Connection ports | Max / precharged pipe length |
|---|---|---|---|---|---|
| AOTH24KBCA3 | 2-3 | 6.8 kW 1.8-8.5 kW | 8.0 kW 2.0-9.2 kW | A-C | 50 m / 30 m |
| AOTH30KBTA4 | 2-4 | 8.0 kW 2.4-10.1 kW | 9.6 kW 3.0-12.0 kW | A-D | 70 m / 40 m |
| AOTH36KBTA5 | 2-5 | 10.0 kW 3.5-12.5 kW | 12.0 kW 3.5-14.0 kW | A-E | 80 m / 50 m |
| AOTH45KBTA5 | 2-5 | 12.5 kW 3.5-14.0 kW | 13.5 kW 3.5-16.0 kW | A-E | 80 m / 50 m |
All four outdoor units: single phase 220-240 V, R32 refrigerant, maximum 15 m height difference between the outdoor and indoor units, and maximum 10 m height difference between indoor units.
2. Indoor capacity classes and model reference
The connection charts use a capacity-class number rather than the indoor unit's full model number. Convert every proposed indoor unit to the class below, then check the exact class combination against the applicable outdoor unit chart.
| Class | Nominal class | Compatible indoor models |
|---|---|---|
| 7 | 2.0 kW | ASTH07KMCD |
| 9 | 2.5 kW | ARTH09KLLAP, ARTH09KSLAP, ASTH09KMCD, AUTH09KVLA-GR, AGTG09KVCA* |
| 12 | 3.5 kW | ARTH12KLLAP, ARTH12KSLAP, ASTH12KMCD, AUTH12KVLA-GR, AGTG12KVCA* |
| 14 | 4.0 kW | ASTH14KMCD, AGTG14KVCA* |
| 18 | 5.0 kW | ARTH18KLLAP, ARTH18KSLAP, ARTH18KMTAP, ASTH18KMTD, AUTH18KVLA-GR, ABTH18KRTA |
| 22 | 6.0 kW | ASTH22KMTD |
| 24 | 7.0 kW | ARTH24KMTAP, ASTH24KMTE |
*Five-room restriction: AGTG09KVCA, AGTG12KVCA and AGTG14KVCA floor-mounted indoor units are not compatible with AOTH36KBTA5 or AOTH45KBTA5.
3. Approved combination capacity envelopes
The table below summarises the approved connection-chart envelope by outdoor model and number of connected indoor units. A total that falls inside the stated range is not automatically approved; the individual class combination must also appear in the manufacturer's connection chart.
| Outdoor model | 2 indoor units | 3 indoor units | 4 indoor units | 5 indoor units |
|---|---|---|---|---|
| AOTH24KBCA3 | Total class 14-32 | Total class 21-36 | Not permitted | Not permitted |
| AOTH30KBTA4 | Total class 29-48 | Total class 25-49 | Total class 28-49 | Not permitted |
| AOTH36KBTA5 | Total class 31-48 | Total class 27-54 | Total class 28-54 | Total class 35-54 |
| AOTH45KBTA5 | Total class 36-48 | Total class 34-62 | Total class 34-62 | Total class 35-62 |
Common approved examples
| Outdoor | Example class combination | Total class |
|---|---|---|
| AOTH24KBCA3 | 7 + 9; 9 + 18; 7 + 7 + 12; 9 + 9 + 18 | 16; 27; 26; 36 |
| AOTH30KBTA4 | 7 + 22; 12 + 24; 7 + 9 + 18; 7 + 9 + 14 + 18 | 29; 36; 34; 48 |
| AOTH36KBTA5 | 9 + 22; 18 + 24; 7 + 9 + 18; 7 + 7 + 12 + 24; 7 + 7 + 9 + 12 + 18 | 31; 42; 34; 50; 53 |
| AOTH45KBTA5 | 12 + 24; 24 + 24; 7 + 24 + 24; 9 + 9 + 18 + 24; 7 + 9 + 12 + 14 + 18 | 36; 48; 55; 60; 60 |
Ducted-unit combination restrictions:
• On AOTH24KBCA3, the combinations 7 + 7 + 18, 7 + 9 + 18, and 9 + 9 + 18 cannot use the mid-static slimline indoor unit as the class 18 unit.
• On AOTH36KBTA5, up to two medium-static-pressure ducted units can be connected in an approved combination.
• On AOTH45KBTA5, up to two medium-static-pressure ducted units can be connected; however, the charted combination 7 + 9 + 9 + 18 + 18 permits only one medium-static-pressure ducted unit.
• On AOTH24KBCA3, the combinations 7 + 7 + 18, 7 + 9 + 18, and 9 + 9 + 18 cannot use the mid-static slimline indoor unit as the class 18 unit.
• On AOTH36KBTA5, up to two medium-static-pressure ducted units can be connected in an approved combination.
• On AOTH45KBTA5, up to two medium-static-pressure ducted units can be connected; however, the charted combination 7 + 9 + 9 + 18 + 18 permits only one medium-static-pressure ducted unit.
4. Outdoor connection ports and pipe sizes
Match each indoor unit pipe size to a suitable outdoor connection. Port A is the largest connection on every model. Port B is also a large-gas connection on the four- and five-port outdoor units.
| Outdoor model | Port A | Port B | Port C | Port D | Port E |
|---|---|---|---|---|---|
| AOTH24KBCA3 | 6.35 / 12.70 mm | 6.35 / 9.52 mm | 6.35 / 9.52 mm | - | - |
| AOTH30KBTA4 | 6.35 / 12.70 mm | 6.35 / 12.70 mm | 6.35 / 9.52 mm | 6.35 / 9.52 mm | - |
| AOTH36KBTA5 | 6.35 / 12.70 mm | 6.35 / 12.70 mm | 6.35 / 9.52 mm | 6.35 / 9.52 mm | 6.35 / 9.52 mm |
| AOTH45KBTA5 | 6.35 / 12.70 mm | 6.35 / 12.70 mm | 6.35 / 9.52 mm | 6.35 / 9.52 mm | 6.35 / 9.52 mm |
Connection planning: Class 18, 22 and 24 indoor units generally use a 12.70 mm gas connection and must be allocated to a matching large-gas outdoor port. Class 7, 9, 12 and 14 indoor units generally use a 9.52 mm gas connection. Confirm the actual indoor model pipe size before assigning ports or ordering reducers.
5. Combination selection and connection check
- Select the outdoor unit based on the required number of rooms and the calculated building loads.
- List every indoor model and convert it to capacity class 7, 9, 12, 14, 18, 22 or 24.
- Confirm the exact class combination appears in the connection chart for that outdoor model and room quantity.
- Check indoor-style restrictions, including the floor-unit restriction on five-room systems and the ducted-unit limits.
- Assign the piping ports so each indoor unit gas pipe matches an available 9.52 mm or 12.70 mm outdoor connection.
- Check total and individual pipe lengths, height differences, additional charge requirements and installation access against the current technical manual.
- Check room design loads. An approved connection combination confirms equipment compatibility; it does not confirm that each indoor unit or the outdoor unit is correctly sized for the application.
Worked example
Proposed system: AOTH36KBTA5 with ASTH07KMCD + ASTH09KMCD + ARTH12KSLAP + ARTH18KMTAP.
Capacity classes: 7 + 9 + 12 + 18 = total class 46.
Combination check: This exact four-unit combination is included for AOTH36KBTA5.
Port check: The class 18 ARTH18KMTAP uses a 12.70 mm gas pipe and should be connected to port A or B. The class 7, 9 and 12 units can use ports C, D and E with 9.52 mm gas connections.
Result: The equipment combination and available port sizes are compatible, subject to final piping-length, charge and load-design checks.
Capacity classes: 7 + 9 + 12 + 18 = total class 46.
Combination check: This exact four-unit combination is included for AOTH36KBTA5.
Port check: The class 18 ARTH18KMTAP uses a 12.70 mm gas pipe and should be connected to port A or B. The class 7, 9 and 12 units can use ports C, D and E with 9.52 mm gas connections.
Result: The equipment combination and available port sizes are compatible, subject to final piping-length, charge and load-design checks.
6. Key operating and design notes
- All connected indoor units operate in the same system mode. Simultaneous heating and cooling is not available.
- Each indoor unit can be individually switched and temperature-controlled within the common operating mode.
- The outdoor unit distributes available capacity across the indoor units that are operating. The sum of indoor nameplate capacities is not simultaneously guaranteed at all indoor units.
- Connection approval does not replace a heat-load calculation, airflow design, pipe-sizing check or installation review.
- Products and combinations may change. Always confirm against the current New Zealand technical documentation before quoting or installing.
Source: Fujitsu General New Zealand, Multiple Room Solutions - Multi Systems, August 2025. This article is a selection aid only. Confirm the complete approved combination chart, actual indoor capacities, piping requirements and current installation instructions before installation.