Home / Comparisons / 12,000 BTU wall-mounted heat pumps
HITACHI airHome 800 and SHARP CHU R32, step by step down to −30 °C
Two 12,000 BTU R-32 wall units, ENERGY STAR cold climate certified and offered by AirGreen. Both manufacturers publish their maximum capacities at the same temperatures: −20, −25 and −30 °C. This page shows what each keeps of its rated capacity at each step, then the same points in BTU/h.
Share of the rated capacity certified at 8.3 °C that each unit keeps, step by step. Each unit in its colour.
What the electricity costs, in dollars, winter and summer
AirGreen estimate for the same 12,000 BTU/h zone in Montréal, at Hydro-Québec’s Rate D, taxes included. Both heat pumps are calculated in 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.
How this amount is calculated
- Heat to deliver over the winter. A zone whose heat loss reaches 12,000 BTU/h ( kW) at −23.1 °C, Montréal’s design temperature: kW × 24 h × 4,167 degree-days ÷ (18 − (−23.1)) = kWh of heat for round-the-clock heating, all winter. Heating degree-days (base 18 °C) and design temperature: Natural Resources Canada, HOT2000 climate data, Montréal Intl station. With fewer hours per day (“Heating” slider), the heat is reduced in the same proportion, for the heat pump as for the baseboards: this simplification does not account for recovery after a temperature setback.
- Electricity for heating. Heat pump: heat × 3.412 ÷ HSPF2 Region V, the AHRI certificate value published by NEEP. Region V is the coldest in the standard, and its calculation includes the electric backup expected when the heat pump is no longer enough. Electric baseboards: 1 kWh of electricity for 1 kWh of heat.
- Electricity for cooling. 12,000 BTU/h ÷ SEER2 × hours per day × 60 days ÷ 1,000: the method of Hydro-Québec’s air-conditioning calculator, with the SEER2 seasonal efficiency from the AHRI certificate. The number of hours is a scenario you can set above, from 1 to 24 h. At 24 h, the calculation assumes rated capacity all day long: that is a ceiling, since a variable-speed unit slows down once the room is at temperature.
- Price. Hydro-Québec Rate D in effect April 1, 2026: 7.065¢ per kWh up to 40 kWh a day, 11.142¢ beyond; the average price, 9.104¢, is the one Hydro-Québec’s calculators use. GST and QST included. Network access charges, the same with or without a heat pump, are not counted.
AirGreen method v1.1, November 9, 2026. An estimate is used to compare units under the same conditions. The actual bill depends on the house, the insulation, the settings and the use; this amount is not a promise.
What each unit keeps of its rated capacity at −20, −25 and −30 °C
Every heat pump has a rated heating capacity, certified at 8.3 °C outdoors: 12,500 BTU/h for the airHome 800, 16,000 BTU/h for the SHARP CHU. As the temperature drops, the maximum capacity changes. HITACHI and SHARP publish their maximums at the same three temperatures below −15 °C, which lets you read them step by step. Tap a column to see the figures and their source.
For 1 kWh of electricity, the heat delivered at four temperatures
One square stands for 0.25 kWh of heat. An electric baseboard delivers four per kilowatt-hour, whatever the temperature. The COPs below are certified in NEEP at maximum capacity, at the same four temperatures for both units.
Same temperature for both
8.3 °C47 °F
−8.3 °C17 °F
−15 °C5 °F
−30 °C−22 °F
Source: NEEP, COP at maximum capacity, 21.1 °C indoors. At −30 °C, the airHome 800’s certified COP is 1.06, nearly that of a baseboard (1.00); the SHARP CHU’s is 1.80. At 8.3 °C, the airHome 800’s is the higher one: 3.26 versus 3.17.
Below −15 °C: three temperatures published by both manufacturers
HITACHI and SHARP publish their maximums at −4, −13 and −22 °F. SHARP adds a point at −17 °F. At −20 and −25 °C, the values come from manufacturer documents, outside the certificate; at −30 °C, they are certified in NEEP.
What each manufacturer writes, card by card
Sources: HITACHI airHome 800 brochure (Johnson Controls-Hitachi Air Conditioning, December 2024), technical catalogue and installation manual IA2693:A; SHARP “CHU/CU Series” catalogue (version MNSPLT-CHUCU 1.1.1) and SHARP submittal sheet AE-X12CHU_AY-XP12CHU-EN1 (January 2026). Each card repeats what the manufacturer writes, without ranking it.
airHome 800: heating published down to −30 °C; “100% heating capacity at −20 °C”; 150 W base pan heater, on at 0 °C outdoors (declared by HITACHI to NEEP).
CHU: heating published down to −30 °C (“High efficiency operation down to −22 °F”); the submittal sheet lists −30 °C as the heating thermal lock-out temperature.
airHome 800: down to −20 °C outdoors.
CHU: down to −10 °C outdoors.
airHome 800: “adaptive defrost technology”.
CHU: reverse-cycle defrost; “Hot Gas Pipe” against ice at the base of the outdoor unit.
airHome 800: Smart Eco, SleepSense, weekly timer.
CHU: Full Power, Eco, 50 °F (10 °C) function, After Care, OD Silent.
airHome 800: RC-BGH1FA0N remote (technical catalogue); airPoint Room H700 controller and third-party thermostat compatible, optional.
CHU: remote control; the “Spot Air” zone is selected from it.
airHome 800: Wi-Fi interface included; airCloud Go app; voice control.
CHU: built-in Wi-Fi adapter (submittal sheet); SHARP AIR app.
airHome 800: not stated in the manufacturer documents consulted.
CHU: automatic louvers in four directions; “Coanda Airflow” up to 50 ft; “Spot Air” over six zones; “Multi Space”.
airHome 800: built-in motion sensor; Smart Eco detects when the room is unoccupied.
CHU: motion sensor, specific to the CHU series.
airHome 800: configurable restart: resume the last mode or disabled (technical catalogue).
CHU: automatic restart; 24-hour timer and 1, 2, 3 or 5 h off timer.
airHome 800: PM2.5 activated-carbon filter and stainless pre-filter; FrostWash 3.0; Mold Guard 2.0.
CHU: filter removable without disassembly; “After Care” dries the inside of the unit after cooling.
airHome 800: five published speeds: SL, S, M, H and HH.
CHU: five published speeds (airflow and sound), unnamed in the sheet.
“Not stated” means the documents consulted are silent on this point, not that the feature is absent.
The sound of each, according to its manufacturer
HITACHI publishes five speeds for the airHome 800, from SL to HH. SHARP publishes five for the CHU, unnamed. Both give a sound pressure in dB(A).
How to read these figures. dB(A) measures a noise level as the ear perceives it: the lower the figure, the quieter the unit. Each dot is a fan speed published by the manufacturer, from the slowest to the fastest.
Why this is not a ranking. HITACHI measures in an anechoic chamber, 1 m from the unit. SHARP publishes neither the distance nor the measurement conditions. A gap of a few dB(A) can come from the method as much as from the unit.
Indoor unit, in the room
Cooling, every published speed
Outdoor unit, outside
Cooling, published value
Measurements taken by each manufacturer using its own method: read them separately, not as a ranking.
Sources: HITACHI airHome 800 brochure (December 2024) and technical catalogue; SHARP submittal sheet AE-X12CHU_AY-XP12CHU-EN1. In heating: 30 to 48 dB(A) for the airHome 800, 22 to 44 dB(A) for the SHARP CHU.
On the wall, outside, in the piping
The two wall units are almost the same width: 1,050 and 1,052 mm. Outside, the SHARP CHU's unit is more compact and weighs 11 kg less. For piping, the airHome 800 is published up to 100 ft, the SHARP CHU up to 66 ft.
Is your wall wide enough?
Unit width only, to scale. The side clearances required by the installation manual are added to it; the installer confirms them on site.
Outdoor unit clearances
airHome 800
HITACHI installation manual IA2693:A gives clearances of 100 to 700 mm depending on the side, with at least three sides open, in a figure; the installer applies them on site.
CHU
The SHARP catalogue and submittal sheet give no clearance figure for the AE-X12CHU outdoor unit; they are found in the installation manual supplied with the unit, which the installer applies on site.
Indoor units to scale
Published widths: 1,050 mm for the airHome 800, 1,052 mm for the SHARP CHU. Manufacturer photos, brought to the same scale.
Piping length
Coloured band: pre-charged length. Dark line: published maximum. Added charge per the manufacturers: 0.11 oz/ft (HITACHI, installation manual IA2693:A) and 0.16 oz/ft (SHARP, submittal sheet); the exact quantity is calculated at installation.
| Installation | airHome 800 | CHU |
|---|---|---|
| Max. piping length | 100 ft30 m | 66 ft20 m; minimum 10 ft |
| Pre-charged length | 49 ft15 m, per installation manual IA2693:A; 0.11 oz/ft added beyond. Factory charge: 2.65 lb. | 25 ftAdded charge: 0.16 oz/ft (15 g/m) beyond 25 ft, per the SHARP submittal sheet. |
| Max. height difference | 65.6 ft20 m | 33 ft10 m |
| Liquid – gas 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 lb850 × 650 × 298 mm, 41 kg | 30.7 × 21.3 × 10.6 in, 67 lb780 × 540 × 269 mm, 30 kg |
| Indoor unit, weight | 41.33 × 11.57 × 10.03 in, 30.07 lb1,050 × 294 × 255 mm, 14 kg. HITACHI prints 11.73 in next to 294 mm; 294 mm gives 11.57 in, the value used here | 41.4 × 12.4 × 9.8 in, 31 lb1,052 × 316 × 249 mm, 14 kg |
| Electrical protectionPer the manufacturer | MOP 25 A (MCA 14 A)airHome 800 brochure, December 2024. | 20 A maximum fuse (15 A breaker, MCA 15.0 A)SHARP submittal sheet. |
| Dehumidification | 3.0 L/hper the airHome 800 brochure. | 0.9 L/h1.9 US pints/h per the submittal sheet, i.e. 0.9 L/h. |
| Published heating / cooling range | −30 to 24 °C / −20 to 46 °C | −30 to 24 °C / −10 to 46 °C |
What people ask about these two wall units
What does “share of rated capacity” mean?
It is the maximum capacity published at a temperature, divided by the rated capacity certified at 8.3 °C: 12,500 BTU/h for the airHome 800, 16,000 BTU/h for the SHARP CHU. At −25 °C, for example, 10,500 ÷ 12,500 gives 84%, and 11,600 ÷ 16,000 gives 72.5%. Each percentage relates to the unit itself.
Which one heats more at −30 °C?
According to NEEP, 9,700 BTU/h maximum for the SHARP CHU and 6,000 BTU/h for the airHome 800, with COPs of 1.80 and 1.06. Both are certified at this temperature, under the same conditions.
HITACHI announces “100% at −20 °C” and the page shows 108%: why?
The HITACHI brochure compares its 13,500 BTU/h at −20 °C with the 13,500 BTU/h rated heating it prints. The AHRI certificate, as carried by NEEP, uses a rated capacity of 12,500 BTU/h at 8.3 °C. This page uses the certified value for both units: 13,500 ÷ 12,500 gives 108%.
Are the values at −20 and −25 °C certified?
No. They come from the HITACHI brochure and the SHARP submittal sheet, and the page marks them “per the manufacturer, not certified”. The values at 8.3, −8.3, −15 and −30 °C are certified in NEEP.
Their HSPF2 values do not point the same way from one region to the other: why?
In Region IV, HSPF2 is 11.5 for the airHome 800 and 11.0 for the SHARP CHU. In Region V, which is colder, it is 8.7 and 9.0. The Region V calculation gives more weight to the cold hours of the season. The estimated cost on this page uses Region V.
Which one is quieter?
In cooling, HITACHI publishes 30 to 48 dB(A) for the airHome 800, measured in an anechoic chamber at 1 m; SHARP publishes 24 to 43 dB(A) for the CHU, without specifying its measurement conditions. These figures situate each unit; they do not allow a ranking.
What happens below −30 °C?
Neither manufacturer publishes a capacity below −30 °C. The HITACHI brochure ends its heating range at −30 °C. The SHARP submittal sheet lists −30 °C on the “Heating Thermal Lock-out / Re-start Temperatures” line.
Are they eligible for grants?
Eligibility depends on the official list in force on the purchase date. This page promises no amount; the current list is checked at the time of the quote.
All AHRI and NEEP values
| Certified value | airHome 800 | CHU |
|---|---|---|
| Cooling | ||
| Rated capacity at 35 °C | 12,500 BTU/h | 12,000 BTU/h |
| SEER2 | 25.0 | 25.0 |
| EER2 | 14.5 | 16.0 |
| Heating, same conditions | ||
| HSPF2 Region IV / V | 11.5 / 8.7 | 11.0 / 9.0 |
| 8.3 °C: min. / rated / max.BTU/h | 4,700 / 12,500 / 19,000 | 3,100 / 16,000 / 22,850 |
| 8.3 °C: COP min. / rated / max. | 2.81 / 3.13 / 3.26 | 5.68 / 4.26 / 3.17 |
| −8.3 °C: min. / rated / max.BTU/h | 4,500 / 11,000 / 16,800 | 5,000 / 18,900 / 18,900 |
| −8.3 °C: COP min. / rated / max. | 1.78 / 2.93 / 2.15 | 2.93 / 2.22 / 2.22 |
| −15 °C: min. / rated / max.BTU/h | 3,500 / 10,500 / 15,200 | 3,850 / 16,000 / 16,000 |
| −15 °C: COP min. / rated / max. | 1.39 / 2.09 / 2.12 | 2.35 / 2.10 / 2.10 |
| Coldest point, same temperature for both | ||
| Test temperature | −30 °C (−22 °F) | −30 °C (−22 °F) |
| Capacity min. / max. | 1,760 / 6,000 BTU/h | 1,350 / 9,700 BTU/h |
| COP at maximum capacity | 1.06 | 1.80 |
| Certifications and refrigerant | ||
| ENERGY STAR / cold climate (NEEP) | Yes / Yes | Yes / Yes |
| ENERGY STAR directory, listed markets | United StatesID 3712587 | United States, CanadaID 4439337 |
| AHRI certificate · NEEP record | 215911631 · 484774 | 217512736 · 507383 |
| RefrigerantGWP per the IPCC (AR4); ASHRAE 34 class | R-32 · GWP 675 · A2L | R-32 · GWP 675 · A2L |
higher marks the higher value of the same measure, under the same conditions. It is not a recommendation. The four heating temperatures are the same for both units. The HSPF2 values are not highlighted: the order changes between Region IV and Region V. The SEER2 values are equal. Capacities and COPs by point are read in the “Three cold steps” and “Efficiency in pictures” sections.
Both are on the AirGreen website.
To choose for your room, talk to our team: bring the room dimensions, the planned outdoor location and your current heating.
Where each figure comes from
Data verified November 10, 2026. Performance: AHRI certificates and the NEEP database. Dimensions, sound, piping and features: according to the manufacturer. When a source contradicts the AHRI certificate, the certificate prevails.
Trademarks. HITACHI, airHome and SHARP are trademarks of their respective owners. Logos are used only to identify the products compared. AirGreen is a dealer for both brands; this page is not produced, sponsored or endorsed by the manufacturers.
Photos: AirGreen and manufacturers, for identification.
Does a figure look wrong to you? Write to us: any reported value is checked again.