Hitachi airHome: the 200 to 800 ladder explained

airHome is Hitachi's wall-mounted single-split family: one indoor unit paired with an outdoor condenser, inverter-driven, on lower-impact R32 refrigerant, and reverse-cycle so it cools in summer and heats in winter. It comes in four tiers, the 200, 400, 600 and 800, plus multi-split indoor options within the 600 and 800 lines for running several rooms off one outdoor unit.

Model codes tell the tiers apart at a glance: the 200 is RAK-CJ, the 400 is RAK-DJ, the 600 is RAK-VJ and the 800 is RAK-XJ (indoor units start RAK-, outdoor units RAC-). The range is now built and backed by Bosch Home Comfort Group, which completed its acquisition of the business on 1 August 2025. Keep it separate from Hitachi's air-to-water airH2O line, which shares the 800 name but is a different product for radiators and hot water.

The four tiers share the same core, so what you are really choosing is how far up the ladder to go. Here is how they compare, from the value entry to the flagship.

airHome 200 is the value entry (RAK-CJ codes). It covers roughly 2.0 to 5.0 kW, rates A++ in cooling and A+ in heating, and starts from about 21 dB(A). It uses a simpler defrost self-clean rather than FrostWash, with eco mode and app control. Choose it for reliable year-round cooling and heating without the extra sensing.

airHome 400 is the mainstream smart tier (RAK-DJ), in capacities up to about 7 kW and still A++. It adds Hitachi's FrostWash self-cleaning, which freezes moisture on the coil then melts it to flush away dust, dirt and mould, plus fuller smart-app control with scheduling, energy monitoring, Alexa and Google Home. The quietest models run from about 20 dB(A).

airHome 600 is the mid-range step up (RAK-VJ). It reaches A+++ cooling on the 2.0 to 3.5 kW sizes (A++ on the larger ones), and adds an occupancy motion sensor that drops to a power-saving mode when the room is empty, a SleepSense function that eases output once you are asleep, an ioniser and four-stage filtration. Night mode drops to around 19 dB(A).

airHome 800 is the flagship (RAK-XJ), in a choice of white or grey. On its 2.5 and 3.5 kW sizes it hits A+++ for cooling and heating with a SCOP up to 5.2, among the best on a domestic split, and runs as quiet as 19 dB(A). It carries FrostWash 3.0, an AQtiv-Ion ioniser, an anti-virus filter and Mould Guard, and HeatForce technology that holds heating output in outdoor temperatures as low as about -15°C.

Prices depend on tier, capacity and how tricky the install is, so treat these as bands and always work from a proper quote. Supplied and fitted, a basic airHome 200 has been advertised from around £1,250. Moving up the ladder, budget roughly £1,400 to £1,900 for a mainstream 400, £1,800 to £2,400 for a 600, and £2,300 to £3,000 or more for a flagship 800. Supply-only unit prices are lower, but you still need an F-Gas registered installer to fit and commission it.

On running costs, a more efficient tier turns each unit of electricity into more heat. At an assumed 25p per kWh, the flagship 800 (SCOP 5.2) delivers a kWh of heat for about 4.8p, against roughly 5.4p for a 200 or 400 (SCOP 4.6). The gap per unit of output is real but modest, so the bigger differences between tiers are up-front price, noise and features. Prices and the unit rate are correct as of July 2026; the Ofgem price cap changes quarterly, so check the current rate.