Installation of a MIDEA MIDEA35 wall-mounted heat pump in Saint-Amable, on Montreal’s South Shore
In Saint-Amable, AirGreen installs a MIDEA MIDEA35 wall-mounted heat pump in a confined space: performance at -30 °C, meticulous HVAC installation, efficiency, and technical advice for the South Shore.
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.
A high-mounted installation designed to make use of the available space without compromising comfort
In Saint-Amable, on Montreal’s South Shore, this installation of a MIDEA MIDEA35 wall-mounted heat pump illustrates a situation we regularly encounter in residential HVAC: the best location for the indoor unit is not always the one that provides the most space around the unit.
In the photo of the completed installation, the heat pump is positioned very high on the wall, close to the ceiling and near a side wall. This compact positioning preserves usable wall space while placing the air outlet at a height favorable for distributing air throughout the room. However, it requires greater precision during installation: the mounting plate, unit level, line routing, condensate drain management, and necessary clearances must all be checked before drilling.
At AirGreen, we never consider the placement of a wall-mounted heat pump as a simple aesthetic decision. The chosen location directly affects airflow, drainage, accessibility forHVAC maintenance, the perceived noise level, and, in the long term, the equipment’s operating quality.
What this Saint-Amable installation photo reveals
The MIDEA indoor unit is installed in the upper part of the wall, and its air outlet louver is open in the photo, indicating that the unit was probably operating when the picture was taken. The overall installation remains discreet despite the space constraint.
One detail is particularly important: when a unit is installed this close to a ceiling or adjacent wall, we must ensure that the clearances specified for the model concerned are respected. It is not enough for the unit to physically “fit” in the available space. The air intake located in the upper section must be able to breathe properly, the panel must remain accessible for filter cleaning, and the discharged air must not be unnecessarily disrupted.
The photo alone does not allow us to measure these clearances to the millimeter or see the outdoor route of the lines. However, it clearly shows the type of challenge an installation team must address: integrate a wall-mounted unit into a restricted space while maintaining a clean, functional installation.
Why the indoor unit’s positioning is crucial
A wall-mounted heat pump works by circulating a large volume of air throughout the room. Poor placement can create significant temperature differences, even when the unit has sufficient capacity on paper.
Before a HVAC installation in Saint-Amable, as with our installations in Montréal, Laval, Longueuil, on the North Shore and the South Shore, we analyze in particular:
- the floor area and layout of the area to be heated and cooled;
- the ceiling height and openings to neighboring rooms;
- the windows and the main sources of heat gain or heat loss;
- the ability to direct airflow toward the useful part of the room;
- the feasible route for the refrigerant lines, wiring, and condensate drainage;
- future accessibility for filter cleaning and maintenance;
- the necessary clearances around the indoor and outdoor units;
- the available electrical capacity and the requirements of the selected model.
This preparation avoids a common mistake: choosing a location solely because it is easy to drill, then trying to adapt the entire installation around that decision.
A much less invasive wall passage than a ducted system
The MIDEA35 series is part of Midea’s ductless systems. In its documentation, the manufacturer explains that the indoor unit is connected to the outdoor unit through a relatively small wall passage, avoiding the major work associated with a traditional duct network.
For a home where opening ceilings and walls to install ventilation would be complicated or costly, this design is a significant advantage.
The passage between the interior and exterior must nevertheless be properly installed. It typically contains the refrigerant lines, communication wiring, and drain. An incorrect drain slope, an improper refrigerant connection, or poor sealing around the wall passage can turn an apparently simple installation into a recurring problem.
Drainage deserves as much attention as the refrigerant lines
In air conditioning and dehumidification, the indoor unit’s evaporator produces condensation. This water must be drained consistently and continuously.
When preparing an installation, we favor gravity drainage whenever the building configuration allows it. The goal is to achieve a sufficient slope and avoid upward runs or sections that could retain water.
In a placement like the one shown at Saint-Amable, the area behind the unit must be planned particularly carefully since the available space is limited. A clean outdoor installation often begins with careful planning of what is behind the appliance, even if these elements are no longer visible once the work is complete.
Sizing is not determined simply by floor area
The exact capacity of the MIDEA35 installed in this photo is not legible. It would therefore be incorrect to arbitrarily assign it a BTU rating.
The range MIDEA35 presented in the manufacturer’s documentation includes three rated cooling capacities: 9,000, 12,000, and 18,000 BTU/h. The corresponding rated heating capacities are respectively 12,000, 12,000, and 20,000 BTU/h.
The right choice depends on the actual heat load. A large window exposed to the sun, an open-plan area, an upper floor, insulation, the number of exterior walls, or airflow to adjacent rooms can significantly change the requirements.
An oversized heat pump is not automatically preferable. A properly selected unit can run longer at a low output, stabilize the temperature, and make better use of the benefits of its variable-speed compressor.
MIDEA35: an extreme heat pump designed for Quebec’s climate
Heating down to -30 °C and R-454B refrigerant
Midea presents the MIDEA35 as its high-end wall-mounted series and as an “extreme heat pump.” According to the supplied technical data sheet, the series uses R-454B refrigerant and has a heating operating range extending down to -30 °C, while cooling operation is advertised from -30 °C to 50 °C.
This low-temperature operating capacity is particularly relevant for an installation in Saint-Amable, where a heat pump must be selected based on the winter realities of the South Shore, and not only for its performance during hot July days.
The manufacturer also identifies the series according to the Cold Climate V6.1.
Up to 33.3 SEER2 and 22.0 HSPF2 depending on capacity
Performance varies depending on the indoor/outdoor combination.
The 9,000 BTU/h version reaches up to 33.3 SEER2 and 22.0 HSPF2 IV. The 12,000 BTU/h version is rated at 29.4 SEER2, while the 18,000 BTU/h version reaches 25.6 SEER2. The AHRI references provided by Midea are respectively 215471386, 215471387, and 215471388.
These figures show why it is important to compare specific model combinations rather than relying solely on the MIDEA35 commercial name.
Two heat pumps in the same series may have different seasonal characteristics, capacities, and even installation requirements.
One particularly interesting figure: capacity at -15 °C
For a homeowner in Quebec, cold-weather heating capacity is often more informative than the rated capacity displayed in large print.
According to the Midea data sheet, at -15 °C, the MIDEA35 models deliver a rated heating capacity of:
9,000 BTU of cooling: 13,500 BTU/h of heating at -15 °C;
12,000 BTU of cooling: 13,500 BTU/h of heating at -15 °C;
18,000 BTU of cooling: 22,600 BTU/h of heating at -15 °C.
The documentation also indicates respective COPs of 3.60, 3.60, and 4.40 under this test condition.
For us, this type of data is essential when comparing Wall-mounted heat pumps for Montréal and the South Shore. Performance in realistic winter temperatures matters more than the maximum performance advertised under moderate conditions.
Different refrigerant lines depending on capacity
Another technical detail can easily go unnoticed.
For the 9,000 and 12,000 BTU MIDEA35 models, Midea specifies liquid/gas lines of 1/4 in and 3/8 in. For the 18,000 BTU version, the dimensions increase to 3/8 in and 5/8 in.
The stated maximum length is 82 ft for the 9,000 and 12,000 BTU models, compared with 164 ft for the 18,000 BTU model.
This difference becomes important when replacing an old heat pump. You should never assume that an old line set is automatically compatible with new equipment simply because the two units appear to have similar capacities.
We check the diameter, condition of the copper, run length, height difference, and the manufacturer’s specific requirements before deciding whether existing infrastructure can be retained.
The electrical supply must also match the exact model
The MIDEA35 documentation specifies a power supply of 208/230 V, single-phase, 60 Hz for all three capacities.
The stated minimum circuit ampacity for the outdoor unit is 16 A for the 9,000 and 12,000 BTU models, and 24.9 A for the 18,000 BTU model. The stated maximum protection is 20 A, 20 A, and 25 A, respectively.
That is why a serious estimate should not consider only the heat pump and its price. The electrical panel, available circuit breaker, wiring, and power supply compliance are all part of the project.
Very quiet indoor operation at low speed
In a bedroom, office, or quiet living room, a few decibels can change the perception of comfort.
For the 9,000 and 12,000 BTU MIDEA35 indoor units, the documentation states a sound level as low as 19 dB(A) in silent mode. For the 18,000 BTU model, the level drops to 16 dB(A) under these conditions.
Midea also offers continuous airflow control with up to 100 fan speed settings as well as remote control through the SmartHome app and Wi-Fi when available for the configuration in question.
This modulation is particularly useful in an installation where the unit is mounted high, as in Saint-Amable: the goal is not simply to deliver a large volume of air, but to adapt it to the room’s actual demand.
Smart sensor, humidity control, and easier maintenance
The MIDEA35 series includes several features that go beyond simply setting a temperature.
The brochure specifically mentions a smart sensor, temperature and humidity control, an A2L refrigerant leak detection sensor, and the option of a wired controller.
Midea also states that the indoor unit’s blower wheel can be removed to facilitate more thorough cleaning.
For us, this point is far from secondary. A ductless heat pump in Montreal, Laval, Longueuil, or the South Shore sometimes operates almost all year round. Dust, moisture, and particles therefore inevitably accumulate on the filters, evaporator, and blower wheel.
A design that facilitates access can makeHVAC maintenance more efficient and help maintain good airflow.
Useful everyday features rather than gimmicks
The series includes ECO, sleep, and silent modes, a timer, “Follow Me” mode, horizontal and vertical swing, and an 8 °C heating setting.
The “Follow Me” mode uses the remote control’s temperature sensor to measure the temperature closer to the occupant rather than exclusively at the wall-mounted unit.
This function is especially useful when the unit is installed near the ceiling. The temperature measured high in a room is not always the same as the temperature felt at human height.
Heating at 8 °C can also be practical for a temporarily unoccupied residence, since the manufacturer specifies it for maintaining a minimum temperature and reducing the risk of freezing.
LogisVert incentive: verify the complete combination before promising an amount
A high-efficiency heat pump may qualify for financial assistance, but the verification must concern the exact combination of the indoor and outdoor units, and not merely identified by the name “MIDEA35.”
For the LogisVert residential measure, Hydro-Québec requires, among other things, that the system be new, certified ENERGY STAR, intended for heating and cooling and equipped with an outdoor unit with a minimum rated capacity of 12,000 BTU/h. The amount and eligibility also depend on the rules applicable on the installation date.
The three MIDEA35 combinations each have their own AHRI number in the manufacturer’s documentation, allowing this verification to be carried out precisely.
In certain multi-unit buildings meeting Hydro-Québec’s specific criteria, an enhancement may increase the assistance to $220 per 1,000 BTU/h at -8 °C for an ENERGY STAR certified cold-climate ductless heat pump. This enhancement is subject to several conditions and therefore does not automatically apply to all residential installations.
We prefer to verify the AHRI number, building type, and program conditions rather than announce an incentive before eligibility has been confirmed.
A residential incentive to verify at the time of registration
The Midea brochure provided indicates that, for residential applications, there is a 12-year limited warranty on the compressor, 12 years on parts, and 10 years on laborThe applicable terms, registration conditions, and criteria should always be verified for the equipment purchased.
This is another factor we include when comparing systems: a heat pump should be evaluated based on its performance, low-temperature operation, noise level, and ease of maintenance, but also on the coverage available after installation.
The mistakes this installation helps avoid
This installation of MIDEA35 in Saint-Amable highlights several simple principles that make a major difference in the field.
Capacity should not be selected solely according to an approximate number of square feet. The unit’s location should not be chosen before checking airflow and the route of the lines. Existing refrigerant lines should not be reused automatically without confirming their diameter. The drain should not be overlooked simply because it is hidden after the work is complete. And a heat pump should not be assumed to qualify for a rebate simply because it belongs to a high-efficiency product line.
These are precisely the details that distinguish an installation that looks right on the first day from an HVAC installation designed to operate properly for years.
AirGreen in Saint-Amable and throughout Greater Montréal
This project in Saint-Amable This is representative of AirGreen’s approach: start with the building’s actual constraints, choose the right equipment and capacity, determine a logical location, and give the same attention to the visible elements as to those that disappear behind the unit.
We install wall-mounted heat pumps throughout Greater Montréal, particularly in Montréal, Laval, Longueuil, on the North Shore and the South ShoreConfigurations vary from one home to another: limited space above a door, a difficult-to-access exterior wall, a long distance to the outdoor unit, an old system to replace, electrical constraints, or the need to distribute heat more effectively among several zones.
Our job is to resolve these constraints before they become problems.
In this installation of MIDEA MIDEA35 in Saint-AmableThe visible result is deliberately understated: a wall-mounted unit installed high up, integrated into a confined space and positioned to preserve as much available wall space as possible. Behind this apparent simplicity are the decisions that really matter in HVAC: sizing, placement, drainage, refrigeration, electrical work, clearances, commissioning, and future maintenance.
How it goes, from the first call to the end
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 the unit delivers when it is cold
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.
And at your place?
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.
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.
Which type of equipment for your project?
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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?
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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).