Installation of a MIDEA MIDEA35 wall-mounted heat pump in Sainte-Clotilde
In Sainte-Clotilde, AirGreen installs a MIDEA35 wall-mounted heat pump above a large window, with precise positioning, heating down to -30 °C, and efficiency of up to 33.3 SEER2.
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The job on one screen
The unit’s data sheet
The range as published on airgreen.ca: pick a size to see its capacity in deep cold.
| Size | Heating at −8 °C | Heating at −15 °C | Coldest certified point | COP at −15 °C | SEER | HSPF | Indicative LogisVert aid |
|---|---|---|---|---|---|---|---|
| Midea Série 35 9 000 | 11,000 | 13,500 | −30 °C: 7,500 | 2.0 | 33.3 | 14.6 | – |
| Midea Série 35 12 000 | 11,000 | 13,500 | −30 °C: 7,500 | 2.0 | 29.4 | 12.7 | $1,320 |
| Midea Série 35 18 000 | 19,300 | 22,600 | −30 °C: 11,900 | 2.34 | 25.6 | 16.2 | $2,316 |
According to NEEP, its certified maximum capacity at −30 °C (−22 °F) is 7,500 BTU/h, 83% of its nominal 9,000 BTU size.
At 8 °C, its certified maximum capacity reaches 17,200 BTU/h, 91% more than its nominal 9,000 BTU size.
According to NEEP, its certified heating capacity at −15 °C (5 °F) is 13,500 BTU/h, 150% of its nominal 9,000 BTU size. Its COP there is 2.00.
According to NEEP, its certified maximum capacity at −30 °C (−22 °F) is 7,500 BTU/h, 62% of its nominal 12,000 BTU size.
At 8 °C, its certified maximum capacity reaches 17,200 BTU/h, 43% more than its nominal 12,000 BTU size.
According to NEEP, its certified heating capacity at −15 °C (5 °F) is 13,500 BTU/h, 112% of its nominal 12,000 BTU size. Its COP there is 2.00.
According to NEEP, its COP at −15 °C is 2.34: the highest of the Série 35 line, which ranges from 2.00 to 2.00 at that temperature.
According to NEEP, its certified maximum capacity at −30 °C (−22 °F) is 11,900 BTU/h, 66% of its nominal 18,000 BTU size.
At 8 °C, its certified maximum capacity reaches 29,700 BTU/h, 65% more than its nominal 18,000 BTU size.
Data read live from the airgreen.ca page of each size (NEEP / AHRI certified performance). When the title names the installed size, it is highlighted; otherwise the whole range is shown. The aid shown is today’s, using Hydro-Québec’s rule ($120 per 1,000 BTU/h at −8 °C); amounts quoted in the article date from its publication. Only Hydro-Québec confirms the assistance granted.A dash in the aid column: amount to be confirmed for this model.
The article, chapter by chapter
An MIDEA35 installation designed specifically for a large window area in Sainte-Clotilde
At Sainte-Clotilde, this installation of MIDEA MIDEA35 wall-mounted heat pump perfectly illustrates a reality we often encounter at AirGreen: the best location for an indoor unit is not always a completely unobstructed large wall. In this residence, a substantial glazed surface occupies nearly the entire lower portion of the wall. The space available for the heat pump was therefore directly above the windows.
In the photo of the completed project, the wall-mounted unit is installed very high, centered above the windows. This configuration keeps the windows completely unobstructed while placing the heat pump in a position favorable for distributing air throughout the room.
What seems simple once the installation is complete nevertheless requires several checks before even taking out the tools. We must consider the available height, the wall structure, the clearance around the unit, the airflow path, condensate drainage, the route of the refrigerant lines, and future access forHVAC maintenance.
In this Sainte-Clotilde, all these elements had to work together.
A heat pump installed above the windows: a technical decision, not merely an aesthetic one
The first advantage of this location is obvious: the wall-mounted heat pump does not encroach on the usable space in the room.
But the choice was primarily functional.
A large glazed surface can strongly influence the indoor temperature. In summer, solar radiation can create a significant cooling load. In winter, windows are generally an area where heat loss is greater than through an insulated wall.
By positioning the MIDEA35 in this area, we can blow conditioned air directly into the room from a high point while keeping the openings fully functional.
However, we must avoid a common mistake: installing the unit as close to the ceiling as possible simply because it physically fits in the available space.
A wall-mounted heat pump must maintain the required clearances for air intake and servicing. The unit must be able to draw in sufficient air through its upper section, and a technician must be able to open the front panel, remove the filters, and access the internal components.
On an installation like the one in Sainte-Clotilde, a few centimeters can therefore determine whether the location is truly suitable.
What we can observe in the completed installation
The photograph shows a white indoor unit installed above windows with dark frames. The air discharge louvers are open, allowing air to exit across practically the entire width of the unit.
The digital display is also visible in the center of the front panel.
Midea provides several control functions on the MIDEA35 series, including sleep mode, silent mode, a timer, fan-speed adjustment, humidity control, horizontal and vertical oscillation, the “Follow Me” function, and an 8 °C heating mode.
The number visible in a photograph alone cannot, however, reliably determine the operating mode active at the time the image was taken. We therefore avoid turning a simple visual observation into a technical conclusion.
Why air circulation is essential in this type of room
A heat pump does not heat a building solely through its number of BTUs. It must also succeed in distributing that energy throughout the space.
In an open room, a high position can help the air stream travel farther. But if the unit is aimed at a beam, partition, or large piece of furniture, even an excellent heat pump may provide less uniform comfort.
The Midea range offers fine ventilation control. The documentation indicates up to 100 levels of airflow adjustment, allowing the airflow to be gradually adjusted to meet comfort needs.
For this installation at Sainte-Clotilde, with the area immediately in front of the unit clear. Airflow can therefore be projected into the room rather than being blocked a few inches after leaving the unit.
The MIDEA35: a heat pump designed for cold conditions
The MIDEA35 Midea presents it as its premium wall-mounted series. It uses the refrigerant R-454B and the documented combinations are listed as Cold Climate V6.1. The heating operating range extends down to -30°C.
This low-temperature operating capability is particularly relevant for a residential installation at Sainte-Clotildewhen the heat pump should not merely provide cooling for a few hot weeks.
We want a unit capable of making a serious contribution to heating during the winter,
The MIDEA35 series shown in the brochure is available in three rated cooling capacities:
- 9,000 BTU/h;
- 12,000 BTU/h;
- 18,000 BTU/h.
The exact combinations and their AHRI reference numbers are documented by Midea.
Three capacities, but different performance
The manufacturer's data show why the term “MIDEA35” is not enough to compare two quotes.
| Version | Rated cooling | Rated heating | SEER2 | HSPF2 IV | AHRI |
|---|---|---|---|---|---|
| 9,000 BTU | 9,000 BTU/h | 12,000 BTU/h | 33,3 | 22,0 | 215471386 |
| 12,000 BTU | 12,000 BTU/h | 12,000 BTU/h | 29,4 | 14,5 | 215471387 |
| 18,000 BTU | 18,000 BTU/h | 20,000 BTU/h | 25,6 | 16,2 | 215471388 |
At -15 °CMidea lists a rated heating capacity of 13,500 BTU/h for the 9,000 and 12,000 BTU versions, and 22,600 BTU/h for the 18,000 BTU version.
These figures are particularly useful when we evaluate a heat pump intended to operate during the winter.
Why we do not indicate a precise capacity for this installation
The photo confirms the presence of a Midea unit from this family, but it does not allow us to read the full model number of the installed unit with sufficient precision.
We therefore prefer not to arbitrarily assign a capacity of 9,000, 12,000, or 18,000 BTU to this installation from Sainte-Clotilde.
In an installation file, the indoor unit model number and the outdoor unit model number immediately confirm the exact combination.
This is the information we use to validate performance, line dimensions, electrical specifications, and the AHRI number.
Up to 33.3 SEER2 thanks to variable-speed technology
The MIDEA35 can reach 33.3 SEER2 depending on the selected combination. The documentation also indicates up to 22.0 HSPF2.
The high seasonal efficiency works together with variable-speed technology.
Rather than continually asking the compressor to operate at full capacity and then shut off, the heat pump can adjust its output according to the room’s needs.
Midea states that this type of operation helps reduce temperature fluctuations and maintain a more stable indoor environment.
In a room with a lot of glazing, this modulation is particularly relevant.
When a cloud passes in front of the sun or the outdoor temperature changes rapidly, the heating or cooling demand can vary. A variable-speed heat pump can adjust its operation rather than responding only through on-off cycles.
The installation details that allow this MIDEA35 to perform well in Sainte-Clotilde
The capacity must match the building, not just the number of square feet
When a homeowner asks what heat pump capacity they need, floor area is only the beginning of the analysis.
For our team, sizing also takes several factors into account:
- insulation level;
- number and dimensions of the windows;
- sun exposure;
- actual room volume;
- ceiling height;
- layout of the spaces;
- possible air circulation;
- thermal losses;
- heating and cooling needs.
A large amount of glazing, like the one visible in this project from Sainte-Clotilde deserves particular attention.
Two rooms with exactly the same floor area may require different capacities when one has significantly more glazing.
The unit’s dimensions must be verified before installation
The 18,000 BTU model does not have the same physical dimensions as the two smaller versions.
According to the documentation:
- the indoor units of 9,000 and 12,000 BTU measure approximately 37.99 in wide x 9.41 in deep x 12.56 in high;
- the version 18,000 BTU measures approximately 44.88 in x 10.83 in x 14.57 in.
When the location is as precise as above the windows in this installation, a difference of almost seven inches in width can obviously change the project's feasibility.
That is why we confirm the model before installation rather than measuring the space based on a generic unit.
The copper also varies by model
Another important difference concerns the refrigerant lines.
The MIDEA35 versions 9,000 and 12,000 BTU use liquid/gas lines of:
1/4 in and 3/8 in.
The version 18,000 BTU uses instead:
3/8 in and 5/8 in.
The published maximum length reaches 82 ft for the 9,000 and 12,000 BTU versions and 164 ft for the 18,000 BTU model.
This point is particularly important when a heat pump replaces an older system.
We never automatically assume that existing lines are compatible. Their diameter, condition, and routing must be checked.
A power supply that also depends on capacity
The MIDEA35 models listed in the documentation operate at 208/230 V, single-phase, 60 Hz.
For the 9,000 and 12,000 BTU versions, Midea specifies a minimum allowable ampacity of 16 A and a maximum protection of 20 A.
For the 18,000 BTU version, the listed minimum ampacity is 24.9 A, with a maximum protection of 25 A.
This demonstrates why the electrical service must never be selected solely based on the old unit.
We base our assessment on the specifications of the model actually installed.
R-454B and A2L equipment
The MIDEA35 operates with R-454B, an A2L-classified refrigerant.
Midea's documentation also mentions a A2L refrigerant leak detection sensor as well as an A2L dispersion system on the applicable series.
For homeowners, this transition to R-454B may seem like a simple refrigerant difference.
For our installation team, it involves following the methods and requirements suited to this generation of equipment during connection, testing, evacuation, and commissioning.
Silence matters when the unit is located directly in the room
A wall-mounted heat pump is installed a few metres from the occupants. Noise level is therefore important.
According to Midea, the 9,000 and 12,000 BTU versions of the MIDEA35 can go down to approximately 19 dB(A) depending on the mode used. For the 18,000 BTU version, the published minimum value is 16 dB(A).
But the noise does not come only from the machine.
Poor fastening, pipes vibrating against the structure, or an improperly positioned panel can create additional sounds.
During our HVAC installation in Sainte-Clotilde, so we pay just as much attention to the mechanical quality of the installation as to the acoustic performance advertised by the manufacturer.
The “Follow Me” function can be useful with a unit placed high up
Warm air naturally rises. In heating mode, the temperature measured very close to the ceiling may therefore differ from that felt lower down in the room.
Midea incorporates a feature called “Follow Me”. The sensor located in the remote control can measure the temperature where it is located, allowing the unit to use this value to adjust its operation.
For a unit installed as high as the one in this project Sainte-Clotilde, this function can help provide a more representative measurement of the area actually occupied.
However, the remote control must be positioned correctly, away from a direct heat source or a very cold window.
A heat pump designed for maintenance
The quality of an installation becomes particularly apparent a few years later, when it is time to perform a thorough cleaning.
Midea documentation indicates that the blower wheel of the MIDEA35, 28, and 25 series can be removed to facilitate access and deep cleaning of the indoor unit.
We find this feature particularly interesting.
The filters can be maintained regularly by the owner, but after several seasons, professional HVAC professional HVAC maintenance may be necessary to clean the heat exchanger, blower wheel, condensate pan, and internal surfaces.
That is why we avoid wedging a wall-mounted unit into a space where it would be practically impossible to open.
An 8 °C hold function that is useful for certain residences
The MIDEA35 also offers a heating mode at 8 °C.
The documentation explains that this function maintains a minimum temperature during a period of vacancy to help prevent the residence from freezing.
For a property that is not occupied permanently, this function may be useful.
It obviously does not replace a complete winter protection strategy, but it is a useful additional setting when the goal is not to maintain a normal comfort temperature.
The AHRI references to keep in the file
The three documented MIDEA35 combinations have the following AHRI numbers:
- 215471386 — MIDEA35 9,000 BTU;
- 215471387 — MIDEA35 12,000 BTU;
- 215471388 — MIDEA35 18,000 BTU.
These numbers are useful when it is necessary to precisely identify a heat pump combination or verify its potential eligibility for a financial assistance program.
However, the brochure provided does not specify the amount of a rebate applicable to this installation. Sainte-Clotilde. We therefore do not present an unconfirmed amount.
The right approach is always to verify the model actually installed and the program criteria in effect when the work is carried out.
A substantial residential warranty
Midea documentation indicates, for the residential sector, a 12-year limited warranty on the compressor, 12 years on parts, and 10 years on labor, according to the program’s applicable conditions.
We recommend carefully keeping:
- the installation invoice;
- model numbers;
- serial numbers;
- the AHRI reference;
- registration documents;
- warranty information.
This documentation greatly simplifies any potential future service.
The mistakes we avoid on an installation like the one in Sainte-Clotilde
An installation above a window requires particular attention.
The first mistake would be to place the unit against the ceiling without respecting its clearances.
The second would be choosing the location solely for its appearance without checking the airflow direction.
The third would be neglecting access to the filters and internal components.
The fourth would be automatically reusing old copper piping without confirming its diameter.
The fifth would be choosing a capacity solely according to the total floor area.
Finally, announcing a capacity, subsidy, or electrical specifications without having confirmed the exact model is a practice we avoid.
A discreet installation that highlights the work carried out behind the result
The final photo of this installation of a MIDEA35 wall-mounted heat pump in Sainte-Clotilde shows an intentionally simple result.
The heat pump occupies the available space above the window. The windows remain completely unobstructed, the unit blows toward the room, and its white appearance blends easily into the wall.
But this result rests on several decisions that are not visible in the photo: sizing, placement, clearance, mounting, refrigerant lines, drainage, electrical supply, and commissioning.
The MIDEA35 brings features suited to four-season use: heating operation down to -30°C, refrigerant R-454B, variable-speed technology, efficiency of up to 33.3 SEER2, precise airflow control, and various capacities available.
At AirGreen, our goal Sainte-Clotilde is precisely to ensure that this technical performance translates into real comfort in the home.
An excellent heat pump that is poorly installed will remain a missed opportunity. A properly sized and positioned MIDEA35, installed with the building in mind, can instead become a particularly effective heating and cooling solution for many years.
The job tools
Two quick checks with real numbers: what heat costs, and what your current heaters add up to in BTU/h.
Baseboards and electric furnaces turn 1 kWh of electricity into 1 kWh of heat. A heat pump delivers more: that is its COP. At Hydro-Québec’s rate D (11.142¢/kWh above 40 kWh a day, since 1 April 2026):
Hydro-Québec: a heat pump can be up to three times more efficient than baseboards for heating in the colder months.
Estimate per kWh of heat, at the chosen temperature, using the certified COP from the product page. Taxes, access charge and backup heat not included.
Conversion: 1 W = 3.412 BTU/h. An indication, not a load calculation: baseboards and furnaces are often stronger than the real need, and they can stay as backup. AirGreen confirms the capacity on site.
How the job unfolds
The main steps of this kind of job at AirGreen. Every house has its quirks: the estimate brings them out.
We look at the room, the outside wall, the line route and where the outdoor unit will go. That is where the capacity gets chosen.
Model, capacity and price, in writing. We also check whether the model qualifies for assistance programs.
Floors and furniture protected, wall plate position marked level, wall opening located.
A single opening, with the slope the drain needs to flow outside.
Set on a stand raised above the snow, with the clearances the manufacturer requires.
Connected, insulated and protected. The opening is then sealed against water, cold air and insects.
A dedicated circuit and an accessible disconnect near the outdoor unit.
Leak test, vacuum, then start-up and a check of heating and cooling.
Remote, modes, filters: we show you the essentials before we leave.
- The on-site estimateWe look at the room, the outside wall, the line route and where the outdoor unit will go. That is where the capacity gets chosen.
- The quoteModel, capacity and price, in writing. We also check whether the model qualifies for assistance programs.
- Getting readyFloors and furniture protected, wall plate position marked level, wall opening located.
- The wall openingA single opening, with the slope the drain needs to flow outside.
- The outdoor unitSet on a stand raised above the snow, with the clearances the manufacturer requires.
- Lines, cable and drainConnected, insulated and protected. The opening is then sealed against water, cold air and insects.
- The electrical workA dedicated circuit and an accessible disconnect near the outdoor unit.
- Tests and start-upLeak test, vacuum, then start-up and a check of heating and cooling.
- The walkthroughRemote, modes, filters: we show you the essentials before we leave.
What we check on a job like this one
Each number is a point we check on site. Switch between summer and winter to watch air and heat move.
In summer, the outdoor unit rejects the house's heat outside.
Generic illustration of this type of installation, not a survey of this job site. Tap a number.
Mounted level on a wall plate, high enough for the air to reach the whole room, with enough space around it to slide the filters out easily.
The refrigerant lines, the communication cable and the drain go through the wall in a single opening, sealed against water, cold air and insects.
Two insulated copper pipes connect the two units. Outside, a line cover can protect them from sun, knocks and weather.
A shut-off switch near the outdoor unit isolates it safely for service. It must stay accessible at all times.
The compressor and the fan. In heating mode it captures heat from the outdoor air, even in winter, and moves it inside.
On the ground or on the wall, it keeps the unit above accumulated snow. The unit stays clear and defrost water can drain away.
The fan needs to blow freely. Storage, a fence or a wall too close, and efficiency drops while noise goes up.
Is your home ready?
Check what applies at your place. A "no" is not a refusal: it is what we sort out during the estimate.
Good habits, once the unit is in place
Six simple habits that keep the unit going. Your list stays on this device.
What to do, season by season
Three habits per season for this unit. They take a few minutes and prevent many calls.
- Clean the indoor unit's filters.
- Clear leaves and debris left on the outdoor unit by winter.
- Test cooling before the first hot days.
- Clean the filters more often when the unit runs a lot.
- Keep plants away from the outdoor unit.
- Check that no water drips from the indoor unit.
- Rake the leaves around the outdoor unit.
- Test heating before the first cold days.
- Book periodic maintenance before winter.
- Keep snow away from the stand and the front of the unit.
- Let the unit defrost: it is normal.
- Never hit the ice on the fins; call us if the unit stays iced up.
The right pages, at the right time
Four statements: true or false?
It all comes down to details you have just seen.
1. In heating mode, the outdoor unit can produce water.
During defrost cycles. That water must drain away without forming ice.
2. You pick the capacity with a simple square-footage rule.
Windows, insulation, orientation and how the room is used all count. Capacity is chosen on site.
3. A multi-zone connects several indoor heads to a single condenser.
One head per room, all on the same condenser. Each room keeps its own temperature.
4. The disconnect can sit behind the patio furniture.
It must stay accessible: it is what shuts the unit off for service.
0 / 4 right answers
What people ask us about this kind of work
Does a wall-mounted heat pump heat in winter?
Wall-mounted or multi-zone: how do I choose?
Where does the outdoor unit go?
Are there grants?
Do I need a permit?
How cold can it heat?
How much can I save?
How is the LogisVert assistance calculated?
Is it noisy?
The outdoor unit is covered in ice: is that normal?
Does AirGreen hold the required licences?
Is the estimate free?
No question matches. Write to us: we answer.
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Text and photo: a real AirGreen Climatisation & Chauffage job. The diagrams are generic illustrations of the type of installation, not a survey of this job site. Sources of the added figures: airgreen.ca product pages (NEEP / AHRI performance), Hydro-Québec (Heat pumps page, LogisVert, read on 13 October 2026), Régie de l’énergie (rate D as of 1 April 2026).