Home / Comparisons / 12,000 BTU wall-mounted heat pumps
HITACHI airHome 600 and airHome 800: what changes from one series to the other
Two 12,000 BTU HITACHI series, with an outdoor unit of the same dimensions according to HITACHI. The 800 mainly adds cooling efficiency (SEER2 25.0 against 20.0) and a colder certified point (−30 °C against −25 °C). In seasonal heating, Region V, the 600 has the higher value. Here is every documented difference.
HITACHIairHome 600 · 12,000 BTU
RAK-GJ12PHAA / RAC-GJ12WHAA · AHRI 215413019
See the product page
HITACHIairHome 800 · 12,000 BTU
RAK-XJ12PHAA / RAC-XJ12WHAA · AHRI 215911631
See the product pageWhat the electricity costs, in dollars, winter and summer
AirGreen estimate for the same 12,000 BTU/h zone in Montréal, on Hydro-Québec Rate D, taxes included. Both heat pumps are calculated exactly the same way, with the same method as on all our comparison pages; only their certified efficiencies change. Electric baseboards serve as the reference point.
Read with the result. The 600 has the higher HSPF2 Region V (9.0 against 8.7): its estimated winter costs a little less. The 800 has the higher SEER2 (25.0 against 20.0): its summer costs less. Depending on your heating and cooling hours, the annual gap changes direction; the sliders show it.
How this amount is calculated
- Heat needed over the winter. A zone whose heat loss reaches 12,000 BTU/h (3.52 kW) at −23.1 °C, Montréal’s design temperature: 3.52 kW × 24 h × 4,167 degree-days ÷ (18 − (−23.1)) = 8,558 kWh of heat for round-the-clock heating, all winter. Heating degree-days (18 °C base) and design temperature: Natural Resources Canada, HOT2000 climate data, Montréal Intl station. With fewer hours a day (“Heating” slider), the heat is reduced in the same proportion, for the heat pump and for the baseboards alike: a simplification that ignores the recovery after a temperature setback.
- Electricity for heating. Heat pump: heat × 3.412 ÷ HSPF2 Region V, the value of the AHRI certificate published by NEEP. Region V is the coldest in the standard, and its calculation includes the backup electric heat expected when the heat pump can no longer keep up. Electric baseboards: 1 kWh of electricity for 1 kWh of heat.
- Electricity for cooling. 12,000 BTU/h ÷ SEER2 × hours a day × 60 days ÷ 1,000: the method of Hydro-Québec’s air-conditioning calculator, with the seasonal SEER2 efficiency from the AHRI certificate. The number of hours is a scenario, adjustable above from 1 to 24 h. At 24 h, the calculation assumes rated capacity all day long: that is a maximum, since a variable-speed unit slows down once the room is at the right temperature.
- Price. Hydro-Québec Rate D in effect on April 1, 2026: 7.065¢ per kWh up to 40 kWh a day, 11.142¢ above that; the average price, 9.104¢, is the one Hydro-Québec’s calculators use. GST and QST included. Grid access charges, the same with or without a heat pump, are not counted.
AirGreen method v1.1, November 9, 2026. An estimate is for comparing units under the same conditions. The actual bill depends on the house, its insulation, the settings and how it is used; this amount is not a promise.
What changes between the 600 and the 800, part by part
Pick a part of the system. Only the differences documented by HITACHI (airHome 600 brochure of March 2025 and airHome 800 brochure of December 2024) are highlighted in yellow; what is identical is shown too.
Below −15 °C: the 600 stops at −25 °C, the 800 goes down to −30 °C
Both HITACHI brochures publish the maximum capacity at −20 and −25 °C, the same method from the same manufacturer: these two temperatures compare directly. NEEP certifies −15 °C for both, then −25 °C for the 600 and −30 °C for the 800.
At −20 °C: 11,200 BTU/h (600) and 13,500 BTU/h (800); at −25 °C: 8,800 and 10,500 BTU/h, per the HITACHI brochures. At −30 °C, only the 800 has a point; HITACHI states a heating range for the 600 that stops at −25 °C.
What each manufacturer writes, feature by feature
Only the features named in the documents we read are listed. When a document says nothing about one, we say so: that does not mean the feature does not exist.
This is the low operating limit HITACHI states for each series.
Defrost water must drain under the outdoor unit without freezing.
Cleanliness of the indoor coil and filter.
To adjust the unit remotely.
Same names in both brochures.
Amount of water removed from the air in cooling, per HITACHI.
| Documented feature | airHome 600 | airHome 800 |
|---|---|---|
| Base pan heater | Yes “Basepan heater”, March 2025 brochure; 150 W per the NEEP record | Yes 150 W per the NEEP record; not named in the Dec. 2024 brochure |
| Adaptive defrost | Yes Adaptive Defrost Technology | Yes Adaptive Defrost Technology |
| Wi-Fi app | Yes airCloud Go | Yes airCloud Go |
| Filter and automatic cleaning | Yes FrostWash 3.0, Mold Guard | Yes FrostWash 3.0, Mold Guard 2.0 |
| Voice control | Not published by the manufacturer March 2025 brochure | Yes Dec. 2024 brochure |
Indoor unit sound, fan speed by fan speed
Published indoor sound pressure
Each point is a fan speed published by HITACHI, in heating.
How to read these figures. The lower the decibels, the quieter the unit. Each point is one published fan speed. A rise of 10 dB(A) is heard as roughly twice as loud.
Why this is not a ranking. Both series come from the same manufacturer and their brochures show the same five fan speeds, but HITACHI gives neither the measuring distance nor the room. Read the two series speed by speed, with that caveat.
Measured by each manufacturer with its own method: same presentation at HITACHI, measurement method not specified.
On your wall and in your yard
The two indoor units, widths to the same scale
Width of the unit only, per the manufacturer. The clearances around the indoor unit are given in each manufacturer’s installation manual.
| Installation, per the manufacturers’ documents | airHome 600 | airHome 800 |
|---|---|---|
| Maximum piping length | 82 ft 25 m | 100 ft 30 m |
| Precharged length | Not published by the manufacturer factory charge 2.45 lb (1.11 kg), max. charge 2.67 lb | Not published by the manufacturer factory charge 2.65 lb (1.2 kg), max. charge 2.98 lb |
| Maximum height difference | 49.2 ft 15 m | 65.6 ft 20 m |
| Liquid – gas line diameters | 1/4 – 3/8 in | 1/4 – 3/8 in |
| Outdoor unit W × H × D, weight | 33.46 × 25.59 × 11.73 in, 91 lb | 33.46 × 25.59 × 11.73 in, 91 lb |
| Indoor unit, weight | 37.40 × 11.57 × 9.06 in, 24.3 lb | 41.33 × 11.73 × 10.03 in, 30.07 lb |
| Electrical protection | MCA 14 A · MOP 15 A | MCA 14 A · MOP 25 A |
| Dehumidification | 1.6 L/h | 3.0 L/h |
| Stated heating / cooling range | −25 to 24 °C / −18 to 46 °C | −30 to 24 °C / −20 to 46 °C |
Questions about this pair
What does the 800 add to the 600?
According to HITACHI and NEEP: a higher SEER2 (25.0 against 20.0), a certified point at −30 °C, a heating range down to −30 °C, more published capacity at −20 and −25 °C, longer piping (100 ft) and higher dehumidification (3.0 L/h).
Does the 600 have a measurable advantage?
Yes. On the AHRI certificate, an HSPF2 Region V of 9.0 against 8.7. According to HITACHI, a narrower and lighter indoor unit (37.40 in and 24.3 lb, against 41.33 in and 30.07 lb).
Are the outdoor units the same?
They have the same dimensions and weight according to HITACHI (33.46 × 25.59 × 11.73 in, 91 lb), but different model numbers (RAC-GJ12WHAA and RAC-XJ12WHAA) and different heating ranges.
Which one costs less to run?
With our method, the 600 costs a little less in winter (HSPF2 V of 9.0) and the 800 a little less in summer (SEER2 of 25.0). The annual total depends on the hours chosen in the “Cost by season” module.
Are both ENERGY STAR cold climate?
Yes. Both AHRI certificates (215413019 and 215911631) are listed by NEEP as ENERGY STAR and ENERGY STAR cold climate, checked on November 9, 2026.
What about the warranty?
HITACHI publishes its own terms. The warranty documents come with the quote.
AHRI certificate values, as published by NEEP
| Certified value | airHome 600 | airHome 800 |
|---|---|---|
| Seasonal efficiencies | ||
| SEER2 | 20.0 | 25.0 |
| EER2 | 13.0 | 14.5 |
| HSPF2 Region IV | 11.1 | 11.5 |
| HSPF2 Region V | 9.0 | 8.7 |
| Rated capacity at 35 °C (cooling) | 12,000 BTU/h | 12,500 BTU/h |
| Heating, min. / rated / max. capacity | ||
| Min. / rated / max. capacity at 8.3 °C | 5,500 / 12,000 / 18,000 | 4,700 / 12,500 / 19,000 |
| Min. / rated / max. capacity at −8.3 °C | 3,500 / 9,400 / 16,800 | 4,500 / 11,000 / 16,800 |
| Min. / rated / max. capacity at −15 °C | 3,200 / 11,000 / 14,500 | 3,500 / 10,500 / 15,200 |
| Min. / rated / max. COP at 8.3 °C | 1.61 / 3.78 / 2.40 | 2.81 / 3.13 / 3.26 |
| Min. / rated / max. COP at −15 °C | 1.04 / 2.50 / 1.77 | 1.39 / 2.09 / 2.12 |
| Coldest point (different temperatures) | ||
| Test temperature | −25 °C (−13 °F) | −30 °C (−22 °F) |
| Max. capacity at the coldest point | 8,800 BTU/h | 6,000 BTU/h |
| Max. COP at the coldest point | 1.52 | 1.06 |
| Certification | ||
| Refrigerant | R-32 GWP 675 (IPCC AR4), class A2L (ASHRAE 34) | R-32 GWP 675 (IPCC AR4), class A2L (ASHRAE 34) |
| ENERGY STAR · cold climate | Yes NEEP, Nov. 9, 2026 | Yes NEEP, Nov. 9, 2026 |
| AHRI certificate · NEEP record | 215413019 · 484778 | 215911631 · 484774 |
“higher” marks the higher value of the same measurement, under the same conditions. It is not a recommendation.
Both are on the AirGreen site.
For an estimate visit or a quote on either of these units.
Documents consulted
Data checked on November 9, 2026. Certified values: AHRI certificates published by NEEP. Declared values (sound, dimensions, piping, features): the manufacturers’ documents cited above. When two sources differ, the AHRI certificate prevails.
HITACHI and airHome are trademarks of their respective owners. Logos are used only to identify the products. AirGreen is a retailer of these brands; this page is not produced, sponsored or endorsed by the manufacturers.
Photos: AirGreen and manufacturers, for identification.
Does a figure look wrong? Write to us at sales@airgreen.ca.