Brand: Hitachi

The Hitachi Dodai FrostWash RAK-25REF/RAC-25WEF is a reversible fixed split air conditioner rated at 9000 BTU (2.50 kW cooling, Class A++, SEER 6.10, and 3.40 kW heating, Class A+, SCOP 4.20). Recommended for rooms of around 20 to 30 m², it drops to 22 dB(A) in quiet mode. Its FrostWash technology automatically cleans the heat exchanger through freeze/defrost cycles, removing up to 91% of bacteria and 87% of mould. WiFi remains optional. Installation must be carried out by a certified professional.

Fitted recently for a homeowner who wanted to equip a 22 m² bedroom without overspending. The Dodai's compact chassis genuinely helps when mounting above a door, a real space saver on this job. Once the line was run and the unit commissioned, the room dropped from 28 to 21°C (82 to 70°F) in about twenty minutes, with a measured noise level around 38 to 40 dB(A) on high fan speed, matching the manufacturer's figures. The real standout is the FrostWash cycle: when the unit shuts down, you can watch the heat exchanger frost over and then defrost, flushing out a good share of the built-up grime, a simple mechanism but one that clearly cuts down on the musty smell you get from splits that never get serviced. My one gripe: no WiFi as standard, you need to add the optional AirCloud Home module if remote control matters to the customer, and the English documentation is thinner than what Daikin or Mitsubishi provide. For a contained budget and a genuine focus on air hygiene, this Hitachi remains a solid pick.

The Hitachi Dodai Dual Split 9+9 pairs two identical RAK-25REF indoor units (9000 BTU/h each, 2.50 kW cooling, 3.40 kW heating) with a single RAM-53NE2F outdoor unit, Class A++ in cooling. Recommended for cooling two separate rooms (bedroom, office) without adding a second outdoor unit. Note: unlike the mono-split in the range, the FrostWash self-cleaning cycle cannot be activated on this bi-split configuration. WiFi, via the Hi-Kumo app, remains optional.

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.