A carefully planned high installation to better distribute comfort throughout the living space
This installation of a MIDEA MIDEA28 wall-mounted heat pump in Saint-Zotique perfectly illustrates a reality we often encounter at AirGreen: choosing the right appliance is only part of the work. Its placement, airflow direction, architectural constraints, and the natural movement of air throughout the home play an equally important role in the final result.
In the photo of this installation, the Midea indoor unit is positioned very high on a large, unobstructed wall near the ceiling. The appliance overlooks a living area where a sofa, a plant, a framed artwork, and a staircase railing can be seen. This configuration suggests an open space in which the heat pump must not only condition the area directly in front of it, but also promote efficient air circulation toward adjacent spaces.
The unit is operating when the photo is taken: its digital display indicates 60, and the airflow louvers are open. This detail makes it possible to see the installation as it is actually used, rather than simply seeing a unit mounted on the wall before commissioning.
At AirGreen, we place great importance on this final step. An HVAC installation is not complete when the appliance is simply mounted on the wall. It is complete when the connections have been checked, the drainage is working, communication between the indoor and outdoor units is correct, and the system responds to commands as expected.
Why install a heat pump so high on the wall?
The high positioning of a wall-mounted heat pump generally makes it possible to achieve better air-distribution range.
In this home, Saint-Zotique, the available wall offered an interesting area above the living space. By installing the unit near the ceiling, we can send the air farther into the room rather than creating a heating or cooling zone concentrated solely around the appliance.
However, the right balance must be found.
A heat pump should not be arbitrarily placed against the ceiling. Its air intake must maintain the necessary clearances, and the top panel must remain accessible forHVAC maintenance, particularly filter cleaning.
Before determining the mounting location, we therefore consider:
- the total wall height;
- the proximity of the ceiling;
- the primary airflow direction;
- the furniture layout;
- the presence of a staircase or an opening to another level;
- the dimensions of the indoor unit;
- the route of the refrigerant lines;
- the slope available for the drain;
- future access to the filters and internal components.
A few inches of difference during installation can have a significant impact on accessibility and air distribution.
The staircase visible in the room changes the way the air moves
The railing visible on the right side of the photo deserves particular attention.
In a house with an opening to another level, air does not behave as it does in a completely enclosed room. In heating mode, warm air naturally tends to rise. In cooling mode, cooler air tends to descend and distribute differently.
We must therefore consider the heat pump as part of the entire interior volume, not merely as an appliance intended for the wall in front of which it is installed.
Depending on the building configuration, a location near an open area may allow some of the comfort to spread to adjacent zones. However, this does not replace a load calculation or a true analysis of each room's needs.
Why we chose the MIDEA28 for this type of project
The MIDEA28 is described in the manufacturer's documentation as an premium wall-mounted series and a extreme heat pump, designed to operate in heating mode down to -30°C. It operates with the refrigerant R-454B and bears the designation Cold Climate V6.1.
For a property at Saint-Zotique, this ability to operate at very low temperatures is an essential factor.
A heat pump installed in Quebec must do more than provide effective cooling on hot days. It must also contribute effectively to heating when temperatures drop during the winter.
Five capacities available in the MIDEA28 series
The MIDEA28 series is available in several capacities, allowing us to better tailor the equipment choice to the building.
The Midea brochure lists the following rated cooling capacities:
- 9,000 BTU/h;
- 12,000 BTU/h;
- 18,000 BTU/h;
- 24,000 BTU/h;
- 33,000 BTU/h.
The corresponding rated heating capacities are 12,000, 12,000, 18,000, 29,000, and 36,000 BTU/h.
The photo does not allow us to read the nameplate of the system installed in Saint-Zotique. We therefore do not assign it an arbitrary capacity.
This detail is important. Two units in the same product line can have significantly different performance, dimensions, and installation requirements.
The MIDEA28 AHRI numbers
The MIDEA28 combinations listed by the manufacturer have the following AHRI references:
- 9,000 BTU: 215471380;
- 12,000 BTU: 215471381;
- 18,000 BTU: 215471382;
- 24,000 BTU: 215471383;
- 33,000 BTU: 215471384.
These numbers are particularly important when a homeowner wants to verify whether their heat pump qualifies for financial assistance.
We always recommend checking the exact indoor and outdoor unit combination, rather than relying solely on the MIDEA28 commercial name.
Up to 27.4 SEER2 depending on capacity
Seasonal performance also varies according to the combination.
Midea lists the following SEER2 ratings:
- 27.4 SEER2 for the 9,000 BTU model;
- 25.4 SEER2 for the 12,000 BTU model;
- 21.4 SEER2 for the 18,000 BTU model;
- 21.0 SEER2 for the 24,000 BTU model;
- 19.5 SEER2 for the 33,000 BTU model.
The HSPF2 IV values listed are, respectively, 12.5, 10.5, 11.0, 13.5, and 10.5.
That is why we avoid advertising “up to 27.4 SEER2” as though all MIDEA28 units had exactly that efficiency.
In a serious quote, performance should always be associated with the model actually being offered.
What this MIDEA28 concretely brings to a home in Saint-Zotique
Heating down to -30°C
The five MIDEA28 capacities listed in the brochure have a heating operating range extending down to -30°C. In cooling mode, the stated operating range also extends from -30°C to 50°C.
This feature makes it possible to use the heat pump for a very significant portion of the heating season.
It is nevertheless essential to size the unit properly.
The fact that a heat pump can operate at -30°C does not automatically mean that any capacity will meet all of a home’s needs at such a low temperature.
What the MIDEA28 produces at -15°C
The technical sheet also provides nominal heating capacities at -15°C, a particularly useful point of comparison for Quebec’s climate.
According to Midea:
- 9,000 BTU: 11,500 BTU/h at -15°C;
- 12,000 BTU: 11,500 BTU/h;
- 18,000 BTU: 18,000 BTU/h;
- 24,000 BTU: 24,200 BTU/h;
- 33,000 BTU: 35,000 BTU/h.
These figures give us a better idea of the system’s actual capacity once winter is well established.
Variable-speed technology: avoiding simple on-off cycling
The Midea lineup uses variable-speed technology that allows the compressor to adjust its operation according to heating and cooling needs.
The manufacturer explains that this technology allows the compressor to continue operating at an appropriate speed rather than constantly switching between on and off, thereby helping limit temperature fluctuations.
In an open-concept area like the one visible in the photo of Saint-Zotique, this type of modulation is particularly interesting.
Once the desired temperature is reached, the goal is not necessarily to stop the system abruptly. The unit can reduce its output and operate more gradually to maintain comfort.
Up to 100 fan-speed levels
Midea indicates that its wall-mounted units have 100 airflow adjustment levels. The system can also be controlled remotely with the SmartHome app and Wi-Fi when these features are available in the configuration being used.
This adjustment capability is particularly relevant in the context shown in the photo.
A heat pump installed high on the wall must be able to send air far enough when a rapid temperature adjustment is needed, then reduce its airflow once the room has stabilized.
A wide range of sound levels depending on capacity
Indoor sound levels vary according to capacity.
For the 9,000 and 12,000 BTU versions, the documentation indicates a value as low as 19.5 dB(A) in quiet mode.
The 18,000 BTU model is also rated down to 19.5 dB(A) under this condition. The 24,000 BTU model can go down to 16 dB(A), while the 33,000 BTU model naturally has a higher airflow and displays a higher minimum level.
In a living room or relaxation area, noise reduction can be just as important for comfort as the temperature itself.
The unit’s dimensions must be verified before drilling
The MIDEA28 is available in several indoor sizes.
The 9,000 and 12,000 BTU models measure approximately 31.30 in wide × 8.86 in deep × 11.61 in high.
The 18,000 BTU model measures approximately 37.99 in × 9.41 in × 12.56 in.
The 24,000 and 33,000 BTU models reach approximately 44.88 in wide × 10.83 in deep × 14.57 in high.
In the Saint-Zotique photo, the unit is relatively close to the ceiling. The model’s height and width are therefore factors we must determine before positioning the mounting plate.
A three-inch difference on a specification sheet can become decisive on an actual wall.
Refrigerant piping changes depending on capacity
The piping sizes required for the MIDEA28 are:
- 9,000 BTU: 1/4 in and 3/8 in;
- 12,000 BTU: 1/4 in and 3/8 in;
- 18,000 BTU: 1/4 in and 1/2 in;
- 24,000 BTU: 3/8 in and 5/8 in;
- 33,000 BTU: 3/8 in and 3/4 in.
This variation is particularly important when replacing an old air conditioner or heat pump.
We do not automatically reuse existing copper simply because it is already in the wall. We always check its diameters and compatibility with the new system.
Piping lengths of up to 164 ft
Midea also indicates different maximum lengths depending on capacity:
- 82 ft for the 9,000 and 12,000 BTU models;
- 98.4 ft for the 18,000 BTU model;
- 164 ft for the 24,000 and 33,000 BTU models.
This flexibility can be very practical when the outdoor unit must be positioned far from the indoor unit to comply with architectural or municipal constraints.
R-454B: a new generation of wall-mounted system
The MIDEA28 operates with R-454B refrigerant, classified as A2L.
The brochure also mentions an A2L refrigerant leak detection sensor for the series concerned, as well as a double check of temperature and humidity.
This means that the installation must be carried out according to procedures appropriate for this equipment: proper refrigerant connections, correct circuit preparation, leak testing, and compliant commissioning.
Electrical requirements vary according to capacity
All the MIDEA28 models presented operate on a 208/230 V, single-phase, 60 Hz.
However, the outdoor unit’s minimum ampacity varies considerably:
- 9,000 BTU: 15 A;
- 12,000 BTU: 15 A;
- 18,000 BTU: 19 A;
- 24,000 BTU: 24.9 A;
- 33,000 BTU: 34 A.
The corresponding maximum protection is 15, 15, 20, 25, and 35 A.
The panel and electrical circuit must therefore be checked before confirming a capacity.
Useful features for everyday life
The MIDEA28 shares several comfort features with the MIDEA35 and MIDEA25 series:
- ECO mode;
- Turbo function;
- night mode;
- timer;
- child lock;
- function “Follow Me”;
- automatic cleaning;
- quiet mode;
- 8°C heating;
- horizontal swing;
- vertical swing;
- Wi-Fi control;
- variable fan-speed control;
- smart sensor;
- humidity control.
The Follow Me can be particularly useful when the unit is installed very high.
The remote control sensor allows the system to use a temperature measured closer to where the occupants are located, rather than relying solely on the temperature around the wall-mounted unit.
A unit designed for easy cleaning
The brochure also states that the blower wheel can be removed to facilitate deep cleaning of the indoor unit.
For us, this feature is important.
A heat pump used year-round circulates a considerable volume of air. Periodic filter cleaning and, when necessary, a thorough HVAC maintenance help limit dust buildup on the evaporator and blower wheel.
The visible installation in Saint-Zotique: apparent simplicity, with many decisions behind the wall
Once completed, this installation looks very simple: a white Midea unit, neatly installed high on a white wall.
That is precisely the objective.
The homeowner should not have to look at the technical considerations that made this result possible every day.
On our end, however, we must think about:
sizing, to positioning, to airflow direction, drainage, copper diameters, wiring, refrigerant-line routing, clearances, service access, and commissioning.
The presence of the staircase and the openness of the space also make air circulation particularly important in this project.
Errors we want to avoid during a similar installation
Installing the unit only where it is easiest to drill
The best technical location is not always the fastest to install.
Choosing a capacity that is too high “just to be safe”
A variable-speed heat pump performs best when properly sized for the building’s needs.
Neglecting the clearance above the unit
A unit installed too close to the ceiling can become difficult to maintain or restrict air intake.
Reusing lines without measuring them
MIDEA28 units use several different diameters depending on their capacity.
Forgetting the impact of the staircase and open spaces
Heat and conditioned air can migrate from one level to another. The unit’s location must therefore be studied in the overall context of the home.
Promising a subsidy without checking the AHRI
Any potential financial assistance must always be associated with the exact combination installed and the program rules applicable at the time of the project.
Why this MIDEA28 installation in Saint-Zotique reflects our approach so well
We always strive to achieve a result that looks simple once completed.
In this MIDEA28 installation MIDEA MIDEA28 wall-mounted heat pump in Saint-Zotique, the indoor unit is integrated high up in the living space, positioned to promote air distribution toward the open room while preserving usable wall space.
The MIDEA28 adds features particularly well suited to this use: heating down to -30 °C, multiple capacities available, variable-speed technology, up to 27.4 SEER2, precise fan control, R-454B, and quiet operation.
At AirGreen, we apply the same rigor to each of our HVAC installations in Saint-Zotique and throughout Greater Montreal, including Montreal, Laval, Longueuil, the North Shore and the South Shore.
The model matters. BTUs matter. Efficiency ratings matter.
But it is how all of these features are adapted to the client’s actual home that determines the quality of the installation.