Home / Comparisons / 12,000 BTU wall-mounted heat pumps
GREE EXTRÊME R32 and MIDEA35, two certified data sheets
Two 12,000 BTU wall units, ENERGY STAR cold-climate certified and offered by AirGreen, one on R-32, the other on R-454B. Their NEEP certificates give a minimum and a maximum capacity at each temperature: the gap between the two is the range over which the unit can modulate. This page shows those ranges, then the figures where each brochure departs from its own certificate.
GREEEXTRÊME R32 12,000 BTU
GWH12AVDXE-D6DN***/I / GWH12AVDXE-D6DNA1B/O · AHRI 215386290
Same certified values: GREE AIRY R32 (same AHRI certificate), GREE SAPPHIRE R32 and KINGHOME AIRY R32.
View the product page
MIDEAMIDEA35 12,000 BTU
MSESU-H12B-2A / MO1SS-H12B-2A · AHRI 215471387
Same certified values: SENVILLE ELITE 12,000 BTU (separate AHRI certificate, 217607368).
View 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.
How this amount is calculated
- Heat needed 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 a day (“Heating” slider), the heat is reduced in the same proportion, for the heat pump as for the baseboards: a simplification that does not account for recovery after a temperature setback.
- Electricity for heating. Heat pump: heat × 3.412 ÷ Region V HSPF2, 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 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 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 for comparing units under the same conditions. The actual bill depends on the house, insulation, settings and use; this amount is not a promise. The MIDEA35 is calculated with its certificate (HSPF2 V 9.5), not with its brochure value.
From the smallest to the largest heat output, at each temperature
A variable-speed unit slows down when the room asks for little, and speeds up when it asks for a lot. NEEP publishes both ends of that range: the minimum capacity and the maximum capacity, with the rated capacity in between. The lower the minimum, the further the unit can slow down before it has to stop; the higher the maximum, the more heat it keeps in reserve. Tap a temperature to read it.
NEEP-certified values (records 389444 and 387352), accessed November 9, 2026. In COP mode, each point is the COP measured at minimum, rated or maximum capacity; NEEP does not publish a rated capacity at −30 °C. The ratio between maximum and minimum is an AirGreen calculation.
Where each brochure departs from its certificate
Both manufacturers publish brochures that repeat most of the values on the AHRI certificate. Four figures do not match. Everywhere on this page, including the estimated cost, the certificate is the value used.
Two refrigerants in the same class
GWP: 100-year global warming potential, per the IPCC Fourth Assessment Report (AR4). Class A2L: lower flammability, per ASHRAE Standard 34. The refrigerant does not change how to read the certificates: both are tested to the same standard.
Below −15 °C: every published figure, at its exact temperature
NEEP certifies both units at −15 °C and at −30 °C, at the same temperatures. The MIDEA35 is ahead at −15 °C, the EXTRÊME R32 at −30 °C: their curves cross in between, at a temperature no source publishes. Between those points, GREE publishes a percentage curve in its service manual; MIDEA publishes no capacity figure.
The points are not connected: the two lines would cross at a temperature no source gives.
What each manufacturer writes, line by line
GREE Canada EXTRÊME R32 brochure (document 032025), GREE Airy Inverter R32 service manual and GREE AIRY R32 brochure, which carry the same model numbers; MIDEA Canada wall-mounted systems brochure (2025-08-20), whose feature table is shared by the MIDEA35, 28 and 25 series. Base pan heater: data each manufacturer declared to NEEP.
EXTRÊME R32: heating stated down to −30 °C; 72 W base pan heater, runs below 1 °C outdoors or during defrost.
MIDEA35: heating stated down to −30 °C; 150 W base pan heater, switched on for 5 minutes when it is below 3 °C outdoors for 30 seconds, after 25 minutes of heating.
EXTRÊME R32: Wi-Fi (app not named); YBE1FB1F remote.
MIDEA35: Wi-Fi and SmartHome app; voice control, 7-day programmable wired controller and 24 V interface optional; dry contact.
EXTRÊME R32: vertical and horizontal louver swing; multi-speed fan.
MIDEA35: fan speed adjustable from 1 to 100%; horizontal and vertical swing; “Follow Me”.
EXTRÊME R32: “G-AI Learning”; “low-voltage start-up”; restarts with the last settings after a power outage (service manual).
MIDEA35: ECO and “Gear”, Turbo, night mode, quiet mode, 8 °C heating, smart presence sensor.
EXTRÊME R32: 1.4 L/h per the brochure.
MIDEA35: humidity sensor, dual temperature and humidity control; dehumidification capacity not published.
EXTRÊME R32: washable filters, auto-clean; anti-corrosion coated fins; “G10 Inverter”, two-stage variable-speed compressor.
MIDEA35: auto-clean; removable fan wheel for deep cleaning.
How loud each one is, per its manufacturer
GREE publishes eight levels for the EXTRÊME R32, with no speed names. MIDEA publishes four speeds for the MIDEA35, from “Silent” to “High”; the Turbo speed has no figure. Both give a level 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 point is a fan speed published by the manufacturer, from the slowest to the fastest.
Why this is not a ranking. Neither GREE nor MIDEA publishes the distance or the measurement conditions in the brochures consulted. A difference of a few dB(A) can come from the method as much as from the unit.
Indoor unit, in the room
Every published speed
Outdoor unit, outside
Highest published speed
Measurements taken by each manufacturer with its own method: read them separately, not as a ranking.
Sources: GREE Canada EXTRÊME R32 brochure (document 032025) and GREE Airy Inverter R32 service manual, which states these are sound pressure figures; MIDEA Canada wall-mounted systems brochure (2025-08-20), p. 10.
On the wall, in the piping, outdoors
Is your wall wide enough?
Unit width only, to scale. The side clearances required by the installation manual come on top; the installer confirms them on site.
Piping length
Colored band: precharged length. Dark mark: published maximum. Gold mark (EXTRÊME R32): the 65.6 ft in the GREE service manual, more conservative than the brochure. Additions per the manufacturer: 0.2 oz/ft of R-32 (GREE) and 0.16 oz/ft of R-454B (MIDEA).
Indoor units to scale
Width × height × depth per the manufacturers. The two units are almost the same width (0.20 in apart); the EXTRÊME R32 is taller, deeper and 4.9 lb heavier.
| Installation | EXTRÊME R32 | MIDEA35 |
|---|---|---|
| Maximum piping length | 131.2 ftEXTRÊME brochure. The GREE Airy R32 service manual gives 65.6 ft for the 12,000 BTU: to be confirmed at quote time. | 82 ft |
| Precharged length | 24.6 ftGREE AIRY R32 brochure and service manual; add 0.2 oz/ft beyond that. | 24.6 ftAdd 0.16 oz/ft beyond that. |
| Maximum height difference | 82 ftEXTRÊME brochure. Service manual: 32.8 ft. | 49.2 ft |
| Liquid – gas line diameters | 1/4 – 1/2 in | 1/4 – 3/8 in |
| Outdoor unit W × H × D, weight | 34 3/8 × 21 27/32 × 14 51/64 in, 78.3 lb | 35.04 × 26.50 × 13.46 in, 99.65 lb |
| Indoor unit, weight | 33.1 lb | 28.22 lb |
| Electrical protectionPer the manufacturer | MOP 15 A (MCA 11 A) | Max. fuse 20 A (MCA 16 A) |
| Outdoor unit base pan heaterDeclared by the manufacturer to NEEP | Yes, 72 WBelow 1 °C outdoors or during defrost. | Yes, 150 WBelow 3 °C for 30 s, after 25 min of heating, for 5 min. |
| Refrigerant | R-32 | R-454B, 44.09 oz |
| Stated heating / cooling range | −30 to 30 °C / −29 to 50 °C | −30 to 24 °C / −30 to 50 °C |
What people ask about these two wall units
Which one heats more on a January night?
At −15 °C, NEEP certifies 13,500 BTU/h at maximum for the MIDEA35 and 12,200 BTU/h for the EXTRÊME R32. At −8.3 °C: 14,600 and 13,000 BTU/h. These are temperatures where both are measured under the same conditions.
And at −30 °C?
At −30 °C, the order flips: 8,500 BTU/h at maximum for the EXTRÊME R32, with a COP of 1.75, and 7,500 BTU/h for the MIDEA35, with a COP of 1.29. No source says at what exact temperature the two curves cross between −15 and −30 °C.
What does a minimum capacity of 4,100 BTU/h at −30 °C mean?
It is the smallest certified heat output of the MIDEA35 at this temperature: its range runs from 4,100 to 7,500 BTU/h. The EXTRÊME R32 runs from 2,600 to 8,500 BTU/h. At −15 °C it is the other way around: the MIDEA35 goes down to 900 BTU/h, the EXTRÊME R32 to 2,600.
The MIDEA brochure says HSPF2 14.5: why does the page say 12.7?
The MIDEA Canada brochure (2025-08-20) prints an HSPF2 of 14.5 in Region IV and 10.0 in Region V. AHRI certificate 215471387, carried by NEEP, shows 12.7 and 9.5. When sources disagree, this page follows the certificate, including for the estimated cost.
R-32 or R-454B: does it change the installation?
Both refrigerants are class A2L under ASHRAE Standard 34. Each unit gets the refrigerant its manufacturer specifies, with its own charging rules: 0.2 oz/ft of R-32 for the EXTRÊME R32, 0.16 oz/ft of R-454B for the MIDEA35 beyond 24.6 ft.
Which one is quieter?
The manufacturers publish 19 to 43 dB(A) for the EXTRÊME R32 and 19 to 41.5 dB(A) for the MIDEA35, with no measurement conditions in the brochures consulted. These figures place each unit; they do not rank them.
MIDEA35 and SENVILLE ELITE: what is the difference?
NEEP publishes the same certified values for the 12,000 BTU MIDEA35 and the 12,000 BTU SENVILLE ELITE, under two different AHRI certificates. The indoor unit, remote, app and warranty can differ by name.
Are they eligible for rebates?
Eligibility depends on the official list in effect on the date of purchase. This page promises no amount; the current list is checked at quote time.
All AHRI and NEEP values
| Certified value | EXTRÊME R32 | MIDEA35 |
|---|---|---|
| Cooling | ||
| Rated capacity at 35 °C | 12,000 BTU/h | 12,000 BTU/h |
| SEER2 | 29.5 | 29.4 |
| EER2 | 15.2 | 14.2 |
| Heating, same conditions | ||
| HSPF2 Region IV / V | 10.0 / 8.0 | 12.7 / 9.5 |
| 8.3 °C: min. / rated / max.BTU/h | 3,270 / 12,200 / 16,200 | 4,000 / 12,000 / 17,200 |
| 8.3 °C: COP min. / rated / max. | 5.04 / 4.53 / 3.77 | 5.86 / 3.59 / 3.17 |
| −8.3 °C: min. / rated / max.BTU/h | 2,800 / 13,000 / 13,000 | 1,600 / 11,000 / 14,600 |
| −8.3 °C: COP min. / rated / max. | 4.32 / 2.06 / 2.06 | 1.88 / 2.41 / 2.26 |
| −15 °C: min. / rated / max.BTU/h | 2,600 / 12,200 / 12,200 | 900 / 13,500 / 13,500 |
| −15 °C: COP min. / rated / max. | 4.23 / 2.00 / 2.00 | 1.15 / 2.00 / 2.00 |
| Coldest point — same temperature for both, not highlighted | ||
| Test temperature | −30 °C (−22 °F) | −30 °C (−22 °F) |
| Capacity min. / max. | 2,600 / 8,500 BTU/h | 4,100 / 7,500 BTU/h |
| COP at maximum capacity | 1.75 | 1.29 |
| Power at maximum capacity | 1.42 kW | 1.70 kW |
| Listings and refrigerant | ||
| ENERGY STAR / cold climate (NEEP) | Yes / Yes | Yes / Yes |
| AHRI certificate · NEEP record | 215386290 · 389444 | 215471387 · 387352 |
| RefrigerantGWP per the IPCC (AR4); ASHRAE 34 class | R-32 · GWP 675 · A2L | R-454B · GWP 466 · A2L |
higher marks the highest value for the same measurement, under the same conditions. It is not a recommendation. Capacities and COPs per point are not highlighted: the order changes depending on the point.
Both are on the AirGreen website.
To choose for your room, talk to our team: bring the room dimensions, the available wall width, the distance to the planned outdoor location and your current heating.
Where each figure comes from
Data checked November 9, 2026. Performance: AHRI certificates and the NEEP database. Dimensions, sound, piping and features: per the manufacturer. When a source contradicts the AHRI certificate, the certificate prevails.
Trademarks. GREE, EXTRÊME, MIDEA and SENVILLE 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? Write to us : any data point reported is checked again.