GENERAL AIRSTAGE Technical Reference
ARTH65KHTA / ARTH72KHTA / ARTH90KHTA
Ducted Systems - Design & Technical Manual
Indoor units ARTH65-90KHTA with AOTH65KBTA / AOTH65KRTA / AOTH72KRTA / AOTH90KRTA outdoor units | R32 inverter heat pump
This article is a quick technical reference to the supplied DR_AR110ES_01 Design & Technical Manual, dated 13 August 2025. It brings together the main design, airflow, piping, electrical and control information used when specifying, installing or supporting these large-capacity ducted systems.
Important: This is a technical reference only. Installation, refrigerant and electrical work must be completed by appropriately qualified personnel. Always confirm the current installation manual, applicable local regulations, site conditions and the full design data before installation or modification.
1. Applicable models
| Indoor unit | Outdoor unit | Power supply | Rated cooling | Rated heating |
|---|---|---|---|---|
| ARTH65KHTA | AOTH65KBTA | 220-240 V, 1N, 50 Hz | 18.0 kW | 20.0 kW |
| ARTH65KHTA | AOTH65KRTA | 380-415 V, 3N, 50 Hz | 18.0 kW | 20.0 kW |
| ARTH72KHTA | AOTH72KRTA | 380-415 V, 3N, 50 Hz | 20.0 kW | 22.4 kW |
| ARTH90KHTA | AOTH90KRTA | 380-415 V, 3N, 50 Hz | 22.4 kW | 25.0 kW |
Indoor unit size: 360 mm (H) x 1,400 mm (W) x 850 mm (D).
Outdoor unit size: 1,418 mm (H) x 970 mm (W) x 370 mm (D).
Outdoor unit size: 1,418 mm (H) x 970 mm (W) x 370 mm (D).
2. Key performance data
| Indoor model | Cooling range | Heating range | High airflow | Indoor sound - High / Quiet |
|---|---|---|---|---|
| ARTH65KHTA | 5.5-20.0 kW | 5.5-22.4 kW | 4,100 m3/h 1,139 L/s | 44 / 35 dB(A) |
| ARTH72KHTA | 6.0-22.4 kW | 6.0-25.0 kW | 4,300 m3/h 1,194 L/s | 46 / 39 dB(A) |
| ARTH90KHTA | 6.5-26.0 kW | 6.5-30.0 kW | 5,040 m3/h 1,400 L/s | 50 / 42 dB(A) |
The manual also contains detailed cooling and heating capacity tables across a range of indoor and outdoor temperatures. These tables should be used where the design condition differs from the rated test condition.
Design point: Capacity is affected by operating temperature, airflow, pipe length and height difference. For long pipe runs or elevated installations, use the manual's capacity compensation tables rather than relying only on nominal capacity.
3. Installation and service space
- Provide sufficient space around both indoor and outdoor units for safe installation, airflow and future servicing.
- The indoor unit manual shows separate layouts for top-access maintenance and service from below.
- Where top maintenance access is provided, the manual shows 450 mm or more above the indoor unit, with 500 mm or more at the service side and 150 mm or more at the opposite side.
- A dedicated maintenance access area is required for the control box, fan units and filter servicing.
- For a single outdoor unit with open space above, typical minimum clearances shown include 100 mm rear, 200 mm side, 300 mm rear when side obstacles are present, and 500 mm front, depending on obstacle arrangement.
- Outdoor units must be installed at least 50 mm above floor level. Snow, drainage and freezing conditions must also be considered.
R32 room-size requirement: The appliance must be installed, operated and stored in a room larger than the minimum floor area specified in the manual. The required area depends on total refrigerant charge and installation height. Check the manual's minimum room-size table before installation.
4. Airflow and external static pressure
All three indoor units have a selectable external static pressure range of 60 to 200 Pa. The standard factory setting is:
| Model | Standard static pressure | Function 26 setting |
|---|---|---|
| ARTH65KHTA | 60 Pa | 31 - Standard |
| ARTH72KHTA / ARTH90KHTA | 72 Pa | 31 - Standard |
Function 26 provides selectable settings from 60 Pa through 200 Pa. Setting value 32 starts Automatic Airflow Adjustment.
Automatic airflow adjustment:
- Set Function 26 to value 32.
- Run the indoor unit in Fan mode at High speed.
- Allow the adjustment to run automatically for approximately 1-8 minutes. Group control may take approximately 10 minutes.
- After the unit stops, turn the air conditioner off and on again.
- Check Function 26 to confirm the setting has changed. Repeat if required.
If the ductwork or outlet arrangement is changed after automatic airflow adjustment, repeat the procedure.
5. Refrigerant piping and charge
| Outdoor model | Liquid | Gas | Factory R32 charge | Additional charge above 30 m |
|---|---|---|---|---|
| AOTH65KBTA / AOTH65KRTA | 9.52 mm (3/8 in) | 15.88 mm (5/8 in) | 3.8 kg | 40 g/m |
| AOTH72KRTA / AOTH90KRTA | 12.70 mm (1/2 in) | 19.05 mm (3/4 in) | 4.5 kg | 60 g/m |
- Pre-charge length: 30 m.
- Maximum total pipe length: 75 m.
- Maximum height difference: 30 m.
- Outdoor operating range: Cooling -15 to 50 degrees C; Heating -20 to 24 degrees C.
Additional charge examples: At 75 m total pipe length, the 65 models require 1.8 kg additional R32 and the 72/90 models require 2.7 kg additional R32. Use the manual's charge table for the actual installed pipe length.
6. Electrical reference
| Outdoor model | Maximum operating current | Reference circuit breaker | Reference power cable |
|---|---|---|---|
| AOTH65KBTA | 30 A | 32 A | 4.0 mm2 |
| AOTH65KRTA | 15 A | 16 A | 2.5 mm2 |
| AOTH72KRTA / AOTH90KRTA | 18 A | 20 A | 2.5 mm2 |
The manual lists a 1.5 mm2 connection cable with a limited wiring length of 76 m and notes that voltage drop should be kept below 2%. Cable size, protection and installation requirements must comply with the applicable regional electrical standards.
7. Controls, external I/O and demand response
Wired controller and group control
- The manual specifies the UTY-RNRT wired touch-panel controller, using non-polar 2-core twisted-pair wiring.
- Group control supports up to 16 indoor units in one system, with total remote-controller cable length up to 500 m.
- When manual remote-controller addressing is required, up to 15 indoor units can be manually addressed.
Common indoor function settings
| Function | Purpose |
|---|---|
| 11 | Filter sign interval |
| 26 | Static pressure / automatic airflow adjustment |
| 30 / 31 | Indoor-unit room-temperature sensor correction for cooling / heating |
| 35 / 36 | Wired-controller room-temperature sensor correction |
| 40 | Auto restart |
| 42 / 48 | Room-temperature sensor selection |
| 43 | Cold-air prevention |
| 46 | External input control - Operation/Stop or Forced Stop |
| 49 | Indoor fan energy-saving control in cooling |
| 60 | External output function |
| 68 / 69 | Auto-mode type and dual-setpoint deadband |
External input and output
- The indoor unit terminal can be configured for Operation/Stop or Forced Stop using Function 46.
- CN47 can provide Operation/Stop, Error Status, Indoor Fan Operation Status or External Heating Device output depending on Function 60.
- The optional UTY-XCSX External Input and Output PCB provides additional external input/output capability.
- Outdoor unit external input functions include Low Noise Mode and Peak Cut Mode. Outdoor outputs can provide Error Status and Compressor Status.
- Outdoor Peak Cut local settings provide 0%, 50%, 75% and 100% rated input-ratio selections.
Demand response
| DR mode | Operation |
|---|---|
| DRM1 | Compressor off. |
| DRM2 | Cooling or heating continues, with half-hour electrical energy limited to no more than 50% of rated-capacity energy. |
| DRM3 | Cooling or heating continues, with half-hour electrical energy limited to no more than 75% of rated-capacity energy. |
The demand-control section specifies a 4-core shielded signal cable, 0.5-1.5 mm2, maximum 30 m, and calls for a compatible smart meter. Follow the dedicated demand-control instructions and applicable AS/NZS requirements.
8. Optional control and integration accessories
| Accessory | Model | Purpose |
|---|---|---|
| Wired Remote Controller | UTY-RNRYT / UTY-RVNYN | Alternative wired control options. |
| Simple Remote Controller | UTY-RSRYT / UTY-RHRYT / UTY-RSNYN | Basic Start/Stop, fan, temperature and/or mode control depending on model. |
| IR Receiver Kit | UTY-LBTYM | Wireless remote-control interface. |
| Remote Sensor | UTY-XSZXT | Remote room-temperature sensing. |
| External I/O PCB | UTY-XCSX | Connection to external devices; bracket UTZ-GXNA is also listed. |
| Zone Control Interface | UTY-CDPXZC / UTY-CDPXZD / UTY-CDRXZC / UTY-CDRXZD | Controls individual zone dampers. |
| Modbus / KNX Converter | UTY-VMSX / UTY-VKSX | Connection to Modbus or KNX open networks. |
| Network Converter | UTY-VTGX | Connects the single-split system to a VRF network. |
| Outdoor External Connect Kit | UTY-XWZXZ3 | Outdoor-unit external input and output functions. |
| L-type Piping Kit | UTP-FX06A | L-type gas-pipe connection for 72 and 90 models. |
9. Full manual contents
Use the attached Design & Technical Manual whenever detailed drawings, wiring diagrams, performance curves or commissioning settings are required.
| Manual section | Technical content | Manual pages |
|---|---|---|
| Indoor unit | Specifications, dimensions, installation and maintenance space, wiring diagrams, capacity tables, fan performance, airflow and sound data. | 2-23 |
| Indoor controls | Safety devices, external I/O, group connection, wired controller, PCB and remote-controller function settings. | 24-50 |
| Indoor accessories | Supplied accessories, controller options and other optional parts. | 51-55 |
| Outdoor unit | Specifications, dimensions, installation space, refrigerant circuits, wiring, capacity compensation, additional refrigerant charge, airflow and sound data. | 58-74 |
| Outdoor controls | Electrical characteristics, safety devices, external I/O, demand control and local function settings. | 75-86 |
| Outdoor accessories | Supplied and optional outdoor-unit parts. | 87-88 |
Design & Technical Manual
Document: DR_AR110ES_01
Issue date: 13 August 2025
Applies to: ARTH65KHTA, ARTH72KHTA, ARTH90KHTA, AOTH65KBTA, AOTH65KRTA, AOTH72KRTA and AOTH90KRTA
Attach the complete PDF to this Freshdesk solution so technicians can access the original capacity tables, diagrams, fan curves and detailed setup procedures.
10. Technical checks before finalising a design
- Confirm the correct indoor/outdoor model combination and power supply.
- Confirm design cooling and heating capacity at the actual ambient and indoor design conditions.
- Confirm duct resistance and select the correct external static pressure / airflow setting.
- Confirm pipe size, total equivalent pipe length, height difference and additional R32 charge.
- Confirm minimum room-size requirements for the total refrigerant charge.
- Confirm indoor and outdoor service clearances.
- Confirm electrical supply, circuit protection, cable sizing and voltage drop.
- Confirm controller type, sensor strategy, zoning, external I/O and BMS integration requirements.
- Where required, confirm demand-response and peak-cut settings before commissioning.
This article is based on Design & Technical Manual DR_AR110ES_01 dated 13 August 2025. Product specifications and design may change without notice. Always refer to the latest official installation, operation and technical documentation before carrying out design, installation, service or commissioning work.