A MIDEA35 installation where the indoor unit’s positioning makes all the difference
In an installation of a wall-mounted heat pump, the choice of equipment matters greatly, but its location in the room can be just as decisive. At Notre-Dame-de-l’Île-Perrot, we installed this MIDEA MIDEA35 wall-mounted heat pump, a series designed to offer particularly strong performance in Quebec’s climate. Midea documentation specifically classifies the MIDEA35 among its ductless wall-mounted systems.
The photo of this installation illustrates a detail we regularly encounter at AirGreen: the available space for installing an indoor unit is not always a completely unobstructed large wall. Here, the wall-mounted head unit was positioned high up, immediately beside a doorway and beneath ceiling trim. This type of location requires careful preparation to preserve airflow, access for maintenance, and the room’s appearance.
In the visible portion of the installation, no exposed refrigerant line cover runs across the wall around the indoor unit. The result remains very discreet in an entirely white décor, where a poorly positioned line set cover or an appliance installed too low would quickly have attracted attention.
A wall-mounted heat pump installed in a constrained architectural space
The ceiling trim and door frame naturally limited the positioning options. A unit installed too close to the ceiling can hinder return-air circulation and make filter cleaning more difficult. If installed too close to the opening, it can also direct a significant portion of its airflow straight toward a passageway rather than toward the room being cooled or heated.
We therefore need to consider several factors before drilling into the wall:
- the clearance required above and around the unit;
- access to the front panel and filters;
- the airflow path;
- the presence of trim, doors, and other architectural elements;
- the ability to drain condensate properly;
- the routing of the refrigerant lines and wiring;
- the outdoor unit’s location;
- easy access for future HVAC maintenance.
In this installation, Notre-Dame-de-l’Île-PerrotThe wall-mounted head unit fits above the passageway without visually encroaching on the main wall. The lower louver visible in the photo is directed toward the living area, allowing the treated air to be distributed into the room rather than remaining concentrated against the ceiling.
Why the path of the lines matters just as much as the heat pump’s position
A ductless wall-mounted heat pump connects the indoor unit to the outdoor unit through refrigerant lines, wiring, and condensate drainage. Midea indicates that this type of system allows installation with a relatively small wall opening and offers considerable flexibility in unit placement.
For a homeowner, the final result often appears simple: a white indoor unit installed on the wall. For our technicians, several checks are involved behind this apparent simplicity.
We pay particular attention to:
Condensate drain slope
In cooling and dehumidification mode, the indoor unit produces water. An improperly sloped drain can cause backflow, drainage noises, or eventually a water leak indoors.
Refrigerant connections
Each connection must be properly prepared and tightened in accordance with the technical requirements. An improper connection can cause a gradual refrigerant leak and significantly reduce the unit’s performance.
Evacuating the system
Before commissioning, moisture and air must be removed from the refrigerant lines. This step helps protect the compressor and ensure the system operates as intended.
Wiring placement
Communication between the indoor and outdoor units must comply with the manufacturer’s electrical requirements. The MIDEA35 notably uses connection wiring 14-4 AWG in the configurations indicated by Midea.
Why the MIDEA35 is particularly well suited to heating and cooling needs in Quebec
The MIDEA35 belongs to the manufacturer’s premium wall-mounted lineup. Midea presents it as an extreme-climate heat pump capable of heating down to -30°C, using the refrigerant R-454B, with efficiencies reaching 33.3 SEER2 and 22.0 HSPF2, depending on the capacity and equipment combination selected.
These features are particularly relevant to Notre-Dame-de-l’Île-Perrot, where a heat pump must do more than cool efficiently in July. It must also be able to provide heating during a significant part of the Quebec winter.
Three different capacities in the MIDEA35 series
The exact capacity of the installed unit is not legible in the provided photo; we therefore prefer not to arbitrarily assign a BTU rating to this installation.
Midea’s technical documentation presents three configurations in the MIDEA35 series:
- 9,000 BTU/h in cooling, AHRI reference 215471386;
- 12,000 BTU/h in cooling, AHRI reference 215471387;
- 18,000 BTU/h in cooling, AHRI reference 215471388.
The listed nominal heating capacities are respectively 12,000, 12,000, and 20,000 BTU/h.
This distinction is important. We avoid choosing a heat pump solely according to the approximate floor area of a home. Two rooms of similar size can have very different heating and cooling loads depending on insulation, sun exposure, the number of windows, the floor, the interior layout, and the amount of air flowing toward neighboring rooms.
Up to 33.3 SEER2: understanding efficiency instead of looking only at BTUs
In the MIDEA35 range, the 9,000 BTU model reaches SEER2 of 33.3, while the 12,000 BTU model reaches 29.4 SEER2 and the 18,000 BTU model 25.6 SEER2.
A high SEER2 rating means that a system can provide substantial cooling relative to the electricity it consumes under the standardized conditions used for certification.
However, it should not be concluded that a smaller unit is automatically preferable because its SEER2 rating is higher. Properly sizing a heat pump remains essential.
An undersized unit may run constantly without managing to maintain the desired temperature during the most demanding periods. Conversely, a unit that is too large for the area may result in cycling that is less favorable for comfort and humidity control.
At AirGreen, the sizing of a wall-mounted heat pump is therefore an integral part of installation quality.
Heating down to -30°C
The three MIDEA35 configurations listed in the documentation have a heating operating range extending down to -30°C. The published heating range is from -30°C to 24°C.
This value does not mean that the capacity is identical at all temperatures. As with virtually all heat pumps, capacity and efficiency change as the outdoor temperature drops.
That is why we also look at cold-weather performance data when recommending a unit for Montreal, Laval, Longueuil, the North Shore, the South Shore, or Vaudreuil-Soulanges.
R-454B refrigerant and the specific features of a modern installation
The MIDEA35 operates with R-454B, an A2L-category refrigerant. Midea documentation specifically mentions an A2L refrigerant leak detection sensor and a corresponding dispersion system on the applicable series.
For us, this reinforces the importance of an installation carried out using the methods, tools, and procedures suited to next-generation systems.
Replacing an old heat pump is therefore not simply a matter of reconnecting two new units to existing piping. The pipe diameter, condition, length, wiring, and installation compliance must all be checked.
Different pipe dimensions depending on capacity
This series is a good example of the importance of checking the exact specifications before installation.
The 9,000 and 12,000 BTU MIDEA35 models use piping of 1/4 in for the liquid line and 3/8 in for the gas line, with a published maximum length of 82 ft.
The 18,000 BTU version instead uses 3/8 in and 5/8 in, with a published maximum length of 164 ft.
Automatically reusing old piping without validating these dimensions is precisely the mistake we seek to avoid during an HVAC installation.
A particularly quiet indoor unit
In a bedroom, living room, or workspace, the noise from the indoor unit can be just as important as its performance.
Depending on capacity, Midea indicates indoor sound levels that can drop to approximately 19 dB(A) for the 9,000 and 12,000 BTU models and up to 16 dB(A) for the 18,000 BTU model under certain operating conditions.
The range also offers precise airflow control. The brochure mentions 100 air volume adjustment levels, as well as remote control through the SmartHome app and Wi-Fi when available.
Useful everyday features, not just specifications on a technical sheet
The MIDEA35 includes several features that can genuinely improve daily use:
- ECO mode;
- Turbo mode;
- sleep mode;
- timer;
- child lock;
- function Follow Me;
- automatic cleaning;
- silent mode;
- 8°C heating;
- horizontal and vertical swing;
- Wi-Fi control;
- smart sensor;
- humidity control;
- option of wired control on compatible configurations.
The Follow Me, for example, uses the temperature sensor integrated into the remote control to adjust operation according to the temperature measured near the user rather than only near the wall-mounted unit.
In an installation like the one photographed in Notre-Dame-de-l’Île-Perrot, where the unit is installed quite high on the wall, this option can be particularly practical for better representing the temperature actually felt in the occupied zone.
A discreet installation must also remain accessible for maintenance
Installing a wall-mounted unit neatly near the ceiling should never prevent its maintenance.
The filters must be removable, and the front panel must remain accessible. Over time, dust and particles can accumulate on the filters, the coil, and the blower wheel.
Midea also designed the MIDEA35, MIDEA28, and MIDEA25 series with a removable blower wheel, designed to facilitate deep cleaning and access to the inside of the unit.
For AirGreen, this aspect is directly part of our thinking when choosing the location: an installation should not only look good on the day we leave the job site. It must remain practical several years later when a technician comes to perform a wall-mounted heat pump cleaning or a service call.
Midea residential warranty
The Midea brochure indicates a residential a 12-year limited warranty on the compressor, 12 years on parts, and 10 years on labor, subject to the terms and conditions applicable to the warranty program.
As always, we recommend keeping the information related to the model, serial number, invoice, and equipment registration.
What about rebates for a MIDEA35?
Eligibility for financial assistance should never be determined solely from the commercial name “MIDEA35.”
It depends in particular on:
- the exact indoor model;
- the exact outdoor model;
- the reference number AHRI;
- the type of building;
- the program in effect at the time of application;
- the other applicable technical and administrative criteria.
That is why we always verify the complete equipment combination when a homeowner wishes to take advantage of a financial assistance program such as those associated with cold-climate heat pumps.
What this Notre-Dame-de-l’Île-Perrot installation illustrates particularly well
This photo might appear to show simply another white heat pump installed on a white wall. To us, it instead highlights several important decisions made during a professional installation.
The unit had to fit between an opening and a ceiling molding. A visually cluttered result had to be avoided. The unit needed to remain accessible. The airflow had to be able to spread toward the area being treated. Finally, all the hidden components—drainage, refrigerant lines, power, and electrical communication—had to work together properly.
It is precisely in these kinds of details that the difference lies between installing a machine and completing a genuine wall-mounted heat pump installation.
In Notre-Dame-de-l’Île-Perrot, as in our projects in Montreal, Laval, Longueuil, on the North Shore and the South Shore, we adapt the installation to the property's actual configuration rather than choosing a location simply because it is quicker to reach.
With a MIDEA MIDEA35, this approach makes it possible to fully benefit from a heat pump designed for extreme-cold heating, variable-speed operation, precise airflow control, and very high-efficiency cooling.
For a homeowner currently comparing different ductless heating and cooling, performance figures are important. But a high-performing system reaches its full potential only when it is properly sized, correctly installed, and intelligently positioned within the space.
It is this combination of equipment selection, HVAC expertise, and installation quality that we seek to replicate on every AirGreen job.