Hitachi Dodai FrostWash Dual Split 9+9
Two rooms cooled with a single outdoor unit: Hitachi's Dodai bi-split air conditioner in 2x9000 BTU, Class A++, for a bedroom and a home office.
Key features
- Power: 2.50 + 2.50 kW cooling, 3.40 + 3.40 kW heating (9000 + 9000 BTU/h)
- Type: Fixed dual split (2 identical indoor units + 1 outdoor unit)
- Noise level: From 22 dB(A) per indoor unit (quiet mode)
- Cools 2 rooms with 1 outdoor unit, SEER 8.10
In detail: Hitachi Dodai FrostWash Dual Split RAK-25REF x2 / RAM-53NE2F, reversible fixed bi-split air conditioner 2x9000 BTU
The Hitachi Dodai FrostWash Dual Split 9+9 is a fixed bi-split air conditioner: two RAK-25REF indoor units at 9000 BTU/h each, connected to a single RAM-53NE2F outdoor unit, for cooling two separate rooms (a bedroom and a home office, say) without adding a second outdoor unit to the facade. A solution built for homes with limited outdoor space, or for anyone wanting to avoid the visual clutter of two separate units.
Each indoor unit delivers 2.50 kW nominal cooling (9000 BTU/h, range 0.90 to 3.10 kW) and 3.40 kW heating (range 0.90 to 4.40 kW), with independent temperature control room by room. The RAM-53NE2F outdoor unit, meanwhile, offers a combined capacity of 5.3 kW nominal cooling and 6.3 kW heating, for a strong seasonal efficiency: SEER 8.10 and SCOP 4.10, above average for this segment, running on R-32 refrigerant.
Compact at 78 cm wide, each indoor unit fits even above a door. Noise drops to 22 dB(A) in quiet mode, with a sound power of 54 dB(A) at full fan speed. On the outdoor unit side, expect 50 to 51 dB(A) depending on mode, with a footprint of roughly 85 x 75 x 30 cm and a weight of 51 kg.
An important point to know before buying: although the indoor units come from the Dodai FrostWash range, the freeze/defrost self-cleaning cycle, which removes bacteria and mould on the mono-split in the same range, can only be activated in a monosplit setup, not on this dual split kit. A distinction not to confuse with the Hitachi Dodai FrostWash 9000 mono-split, which fully benefits from this feature.
WiFi remains optional, via a module compatible with the Hi-Kumo app (rather than AirCloud Home as on the range's mono-split units), which also allows MODBUS and Konnex home automation integration for more advanced setups. Like any split air conditioner, and even more so with two indoor units to connect to the same outdoor unit, installation must always be carried out by a certified professional for vacuum pumping and R-32 refrigerant charging, a regulatory requirement across Europe.
For anyone wanting to cool two rooms with a single outdoor unit without sacrificing energy efficiency, this Hitachi dual split remains a solid option, as long as you accept that the range's FrostWash selling point doesn't apply to this particular configuration.
Technical data
Detailed characteristics (EAN: 8059657009197)
Performance
| Type?General technical category the unit belongs to (portable, split, evaporative...). | Fixed multizone dual split, heat pump (2 identical indoor units + 1 outdoor unit) |
|---|---|
| Cooling capacity (per indoor unit)?The unit's cooling power, expressed in kW or BTU/h (British Thermal Unit per hour). | 2.50 kW nominal (9000 BTU/h) each, range 0.90 to 3.10 kW |
| Heating capacity (per indoor unit)?The unit's heating power, for reversible models working as a heat pump. | 3.40 kW nominal each, range 0.90 to 4.40 kW |
| Combined cooling capacity (outdoor unit)?The unit's cooling power, expressed in kW or BTU/h (British Thermal Unit per hour). | 5.3 kW nominal, range 1.5 to 6.0 kW |
| Combined heating capacity (outdoor unit)?The unit's heating power, for reversible models working as a heat pump. | 6.3 kW nominal, range 1.5 to 6.6 kW |
| Energy class?European energy efficiency class (from A+++ to G), showing how the unit's consumption compares with similar models. | A++ cooling, A+ heating (average climate) |
| SEER (outdoor unit)?Seasonal Energy Efficiency Ratio: the higher it is, the more efficient the unit over a full season of use. | 8.10 |
| Refrigerant?Gas used in the cooling circuit. R290 and R32 are now favoured for their lower environmental impact. | R-32 (GWP 675) |
| Indoor unit noise level (each)?Noise emitted by the unit, in decibels (dB(A)). As a reference, a normal conversation is around 60 dB(A). | 22 to 40 dB(A) cooling, 20 to 41 dB(A) heating, sound power 54 dB(A) |
| Outdoor unit noise level?Noise emitted by the unit, in decibels (dB(A)). As a reference, a normal conversation is around 60 dB(A). | 50 dB(A) cooling, 51 dB(A) heating, sound power 52 to 61 dB(A) |
| Refrigerant line length?Gas used in the cooling circuit. R290 and R32 are now favoured for their lower environmental impact. | 3 m minimum, 35 m maximum per indoor unit, 20 m maximum height difference |
Features and connectivity
| Functions?Operating modes offered by the unit (cooling, fan, dehumidifying, heating...). | Cooling, heating, fan only, dehumidifying, independent setting per room |
|---|---|
| Connectivity?Ways to control the unit remotely (mobile app, WiFi, voice assistants...). | WiFi optional via the Hi-Kumo app, compatible with MODBUS and Konnex home automation |
| Timer?Programmable delay for the unit to switch on or off automatically. | 12 hours, RAR-7PE1 remote included per indoor unit |
Dimensions and power supply
| Indoor unit dimensions (each)?Width, depth and height of the unit (W x D x H). | 21.5 x 78 x 28 cm (depth x width x height) |
|---|---|
| Outdoor unit dimensions?Width, depth and height of the unit (W x D x H). | 29.8 x 85 x 75 cm (depth x width x height) |
| Weight?The unit's weight, an important factor for a portable air conditioner regularly moved between rooms. | 7.7 kg per indoor unit, 51 kg (outdoor unit) |
| Power supply?Electrical voltage and frequency required to run the unit. | 220-240V~, 50Hz |
Additional information
| Indoor unit model | 2x RAK-25REF |
|---|---|
| Outdoor unit model | RAM-53NE2F (Multizone Dodai Series F range) |
| SCOP (outdoor unit) | 4.10 |
| EER | 4.10 |
| COP | 3.90 |
| FrostWash self-cleaning | Indoor units come from the Dodai FrostWash range, but the freeze/defrost self-cleaning cycle can only be activated in a monosplit setup, not on this dual split kit |
| Pipe diameters (per indoor unit) | 1/4" (liquid) and 3/8" (gas) |
| Number of connectable indoor units | 2 (fixed on this outdoor unit, not expandable) |
| Operating range | -10°C to 46°C (14°F to 115°F) cooling, -15°C to 24°C (5°F to 75°F) heating |
| Manufacturer warranty?Period during which the manufacturer commits to repairing or replacing the unit in case of failure, excluding damage or misuse. | 5 years on electronic boards and compressor |
Comparison
In the 800 to 1500€ range, the Hitachi Dodai Dual Split 9+9 regularly comes up against the Ariston Prios Dual Split 9+12, another bi-split kit already in our selection, in searches like "Hitachi vs Ariston dual split air conditioner". Here is how the two kits compare, based on the public specifications of both manufacturers.
| Criterion | Hitachi Dodai Dual Split 9+9 | Ariston Prios Dual Split 9+12 |
|---|---|---|
| Power | 9000 + 9000 BTU/h (symmetrical) | 9000 + 12000 BTU/h |
| Efficiency (outdoor unit SEER) | 8.10 | Not published |
| Self-cleaning | Not available, despite the Dodai FrostWash name | Yes, generic self-cleaning function |
| Follow Me function | No | Yes |
| Typical price | ≈€1486 | ≈€869 |
In short, the Ariston Prios Dual Split stays notably more affordable and offers a genuine self-cleaning function plus Follow Me tracking, two concrete advantages. The Hitachi Dodai Dual Split answers with two strictly identical indoor units (9000 + 9000 BTU, handy for two similarly sized rooms) and strong seasonal efficiency on its outdoor unit, at the cost of a bigger investment.
Related video
Video: Hitachi FrostWash Air Conditioner - Published on 27 June 2019
Our tester's verdict: Christophe Delpuech
Fitted for a couple who wanted to cool their bedroom and home office without adding a second outdoor unit to the building's facade, in a flat with a fussy managing agent. This Hitachi dual split let us connect both rooms to a single RAM-53NE2F outdoor unit, a real selling point for getting the works approved. The two RAK-25REF units, strictly identical, brought each room down from about 29 to 22°C (84 to 72°F) in roughly half an hour, with independent settings for each: quiet night mode in the bedroom, a cooler setting for the office during the day. Measured noise sat around 33 dB(A) on medium fan speed for both units, matching the spec sheet. My clearest gripe: the Dodai FrostWash name on the product listing is misleading, the freeze/defrost self-cleaning cycle that makes the mono-split in this range so appealing simply isn't available here. Second thing to watch: running both units flat out at the same time trims each one's output slightly, since they share the same outdoor unit. For cooling two rooms in one go without adding outdoor clutter, this kit remains a solid option, as long as you accept that trade-off on air hygiene.
Frequently asked questions: Hitachi Dodai FrostWash Dual Split RAK-25REF x2 / RAM-53NE2F, reversible fixed bi-split air conditioner 2x9000 BTU
No: although the indoor units come from the Dodai FrostWash range, the freeze/defrost self-cleaning cycle can only be activated in a monosplit setup. On this dual split kit, this function isn't available.
Yes, each RAK-25REF unit adjusts temperature and mode independently, but both share the same RAM-53NE2F outdoor unit, which can slightly reduce available output if both run simultaneously at full load.
The mono-split cools a single room with its own outdoor unit and benefits from the FrostWash cycle. This dual split cools two rooms with a single RAM-53NE2F outdoor unit, but without FrostWash self-cleaning, which isn't available in this configuration.
No, it requires an optional WiFi module compatible with the Hi-Kumo app (rather than AirCloud Home as on the range's mono-split units), which also allows MODBUS and Konnex home automation integration.
Bracket fitting and site preparation can be done in advance, but connecting both indoor units to the outdoor unit and charging the R-32 refrigerant must always be carried out by a certified professional.
The unit is covered by a 5-year manufacturer warranty on electronic boards and the compressor, under the standard terms applied to the Dodai range.
More products in the "Fixed air conditioner" range
Ariston Prios Dual Split 9+12
Check price (7)
Two rooms cooled with a single outdoor unit: Ariston's dual split fixed air conditioner, with Follow Me function and a refrigerant leak sensor.
Atlantic Murao Access 3.5 kW
569.00€
Atlantic's entry-level reversible split air conditioner, with its refrigerant line factory pre-charged up to 7 metres, for a living room of about 35 to 40 m².
Atlantic Takao M2 Tri-Split 5.4 kW
3299.99€
Three rooms cooled with a single outdoor unit: Atlantic's Takao M2 tri-split kit, 5.4 kW, Class A+++, for a house with several bedrooms.
Daikin ATXC35E
Check price (4)
The reversible Daikin split air conditioner, cooling and heating, with built-in WiFi, for anyone after the brand's reliability without the premium-range price.
Page published on 3 August 2026