A MIDEA28 installation where the choice of a compact location also had to promote air circulation
At Très-Saint-Rédempteur, we completed this The in a room where the available space required particularly precise planning. The photograph of the completed project shows the indoor unit installed in the upper part of a wall, near the ceiling, above a mirror and immediately beside an opening framed in wood.
This type of configuration accurately reflects the real work behind an HVAC installation. We are not simply looking for a surface large enough to mount the unit. We must determine where the equipment can distribute its air effectively, how the refrigerant lines and drain will be routed, how to preserve access to the filters and internal components, and how to integrate the system without interfering with the room’s everyday use.
In this residence in Très-Saint-Rédempteur, the high installation leaves the entire lower part of the wall available. The mirror remains in place, the adjacent opening stays completely unobstructed, and the heat pump occupies an area that otherwise would have had very little use.
The result is compact, but the thinking behind the positioning is not.
A heat pump installed high on the wall to make use of limited space
The photograph shows a common reality in existing homes: the best walls are not necessarily unobstructed.
In this room, several elements influenced the choice of location:
- an opening with wooden trim on the side;
- a mirror mounted lower on the wall;
- a relatively nearby ceiling area;
- a limited section of wall to accommodate the equipment;
- the need to project the air beyond the elements located below the unit.
We therefore used the upper part of the wall.
A wall-mounted unit installed high up can send air farther into the room, provided the clearances required by the manufacturer are respected and the louvers do not immediately direct the airflow toward an obstacle.
But behind this result are sizing, structural verification, drainage, refrigerant lines, electrical work, clearances, commissioning, and future access. MIDEA28 offers particularly fine ventilation control. Midea indicates up to 100 adjustable airflow levels, allowing the airflow to be gradually adjusted according to the actual need rather than limiting the user to a few fixed speeds.
Why clearance near the ceiling requires precision
A wall-mounted heat pump generally draws room air through its upper section before circulating it through its heat exchanger.
When working near a ceiling, we therefore cannot simply ask whether the unit physically “fits.”
You must also consider:
Air intake
The unit must be able to draw in enough air to operate as designed.
Opening the front panel
The filters are located inside the unit. The panel must be able to be opened for inspections and routine maintenance.
Future cleaning
An installation that is too tight can make a HVAC maintenance unnecessarily complex several years later.
Mounting
We must take into account the structure behind the wall and the exact position of the mounting plate.
Drainage
In cooling mode, the water produced by condensation must leave the unit reliably.
These are precisely the elements that turn an apparently simple location into a genuine installation decision.
A particularly practical ductless solution for renovations
The MIDEA28 belongs to the range of Midea ductless wall-mounted systems, alongside the MIDEA35, MIDEA25, and MIDEA22 series.
The principle is particularly well suited to existing residences.
The indoor unit is connected to the outdoor unit by refrigerant lines and the necessary connections, without making it essential to build a complete ventilation duct network throughout the house. Midea documentation specifically points out that an indoor unit can be connected to the outside through a relatively small opening, offering considerable flexibility for renovations.
To Très-Saint-Rédempteur, this flexibility makes it possible to work with the existing layout rather than redoing the entire room around the heating and cooling system.
MIDEA28: five capacities for very different applications
But behind this result are sizing, structural verification, drainage, refrigerant lines, electrical work, clearances, commissioning, and future access. MIDEA28 is not a single heat pump available in only one capacity.
Midea documentation presents five combinations:
| Rated cooling capacity | Rated heating | SEER2 | HSPF2 IV | AHRI number |
|---|---|---|---|---|
| 9,000 BTU/h | 12,000 BTU/h | 27,4 | 12,5 | 215471380 |
| 12,000 BTU/h | 12,000 BTU/h | 25,4 | 10,5 | 215471381 |
| 18,000 BTU/h | 18,000 BTU/h | 21,4 | 11,0 | 215471382 |
| 24,000 BTU/h | 29,000 BTU/h | 21,0 | 13,5 | 215471383 |
| 33,000 BTU/h | 36,000 BTU/h | 19,5 | 10,5 | 215471384 |
The series is rated for heating operation down to offers a particularly flexible range: five capacities from 9,000 to 33,000 BTU, with heating down to, with refrigerant R-454B and classification Cold Climate V6.1 for the combinations presented in the brochure.
For a Très-Saint-Rédempteur residence, winter performance is particularly important. A heat pump must be evaluated not only according to its performance during a hot day in July, but also according to what it can deliver when the outdoor temperature drops well below zero.
The heating capacity at -15 °C provides particularly useful information
Midea also publishes the rated heating capacity at -15 °C for the different MIDEA28 models:
- 9,000 BTU: 11,500 BTU/h;
- 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 values provide a better understanding of the heat pump’s actual behavior when it has to heat under conditions much closer to those encountered during a Quebec winter.
Why we do not provide a precise capacity based solely on the photo
In this Très-Saint-Rédempteur installation, the indoor unit is clearly visible, but the photograph does not allow us to read its complete model number with sufficient precision.
We therefore do not claim to know with certainty whether it is a 9,000, 12,000, 18,000, 24,000, or 33,000 BTU MIDEA28.
To confirm an installation, we always use:
- the indoor unit model number;
- the outdoor unit model number;
- the serial number;
- the AHRI number.
This rigor prevents us from reporting an incorrect capacity, incorrect electrical requirements, or financial assistance that does not correspond to the equipment actually installed.
Up to 27.4 SEER2 with variable-speed technology
The MIDEA28 reaches up to 27.4 SEER2 depending on the selected capacity.
Much of the comfort provided by this type of system comes from its variable-speed technology.
Rather than operating only at full capacity before shutting off, the compressor can adjust its speed to match demand. Midea indicates that this modulation helps reduce temperature fluctuations and maintain a more stable indoor environment.
For the user, the difference can be significant.
Once the desired temperature is reached, the heat pump can gradually reduce its operation instead of waiting for the room to become significantly warmer or cooler before starting a new cycle.
A location near an opening can help distribute air to neighboring spaces
The photo shows the MIDEA28 installed near an interior opening.
This proximity can be beneficial for air circulation.
A wall-mounted heat pump works particularly well in an area where its airflow can travel a certain distance without immediately encountering a wall or large piece of furniture. When passages to other rooms are present, some of the conditioned air can also circulate naturally into neighboring spaces.
However, we must remain realistic: a wall-mounted heat pump is not a central system with ducts that distribute a precise amount of air to each room.
A closed door greatly limits air exchange.
That is why, at AirGreen, we consider the the actual room configuration when choosing the number of units and their locations.
Behind this discreet installation in Très-Saint-Rédempteur: sizing, copper, electrical work, and maintenance
The right number of BTUs depends on much more than floor area
We avoid selecting a heat pump solely based on an approximate BTU-per-square-foot ratio.
We consider, among other things:
- floor area;
- ceiling height;
- the level of insulation;
- windows;
- the building’s orientation;
- solar gains;
- heat loss;
- the number of levels;
- the openness of the rooms;
- occupancy habits.
In the case shown in the photo, positioning near an opening is also part of the analysis.
A higher-capacity heat pump does not automatically guarantee better results. The system must be able to modulate effectively and run long enough to maintain a consistent temperature.
The size of the indoor unit varies considerably depending on the capacity
The available physical space is also a factor.
According to Midea documentation, the dimensions of the MIDEA28 indoor units are approximately:
- 31.30 in wide for the 9,000 and 12,000 BTU models;
- 37.99 in for the 18,000 BTU model;
- 44.88 in for the 24,000 and 33,000 BTU versions.
In an installation like the one at Très-Saint-Rédempteur, where the system must fit between a wall corner, the ceiling, and various architectural elements, this difference is significant.
A unit nearly 45 inches wide obviously cannot be treated like a unit just over 31 inches wide.
Five capacities, four different piping configurations
Copper is another essential detail.
For the MIDEA28, Midea specifies:
- 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 is especially important when replacing an older heat pump.
Seeing two copper pipes coming out of a wall does not mean we can automatically connect them to the new unit.
The diameter must be compatible with the selected system.
The maximum lengths vary as well
The MIDEA28 offers some flexibility in choosing the outdoor unit's location.
The published maximum lengths are:
- 82 ft for the 9,000 and 12,000 BTU models;
- 98.4 ft for the 18,000 BTU;
- 164 ft for the 24,000 and 33,000 BTU versions.
This can be useful when it is preferable to separate the indoor and outdoor locations further to achieve a more logical installation.
However, we are not looking to use these limits unnecessarily. When the building allows for a short, clean route, this option generally remains attractive for simplifying the installation.
Drainage is one of the most important elements that remain unseen
In cooling and dehumidification mode, the indoor unit produces condensation water.
This water must be drained properly.
In a wall-mounted installation, we must plan the drain to prevent:
- negative slopes;
- water buildup;
- indoor leaks;
- odors;
- blockages;
- moisture around the unit.
In the photograph of our installation of Très-Saint-Rédempteur, and no bulky drain is visible beneath the unit. The result looks simple because these elements were integrated into the technical planning rather than left as an afterthought.
Electrical requirements increase with capacity
All the MIDEA28 units shown use a 208/230 V, single-phase, 60 Hz, but their amperage varies considerably.
| Capacity | Minimum allowable ampacity | Maximum protection |
| 9,000 BTU | 15 A | 15 A |
| 12,000 BTU | 15 A | 15 A |
| 18,000 BTU | 19 A | 20 A |
| 24,000 BTU | 24.9 A | 25 A |
| 33,000 BTU | 34 A | 35 A |
This data appears in the MIDEA28 technical specifications.
That is why we do not simply install “the same breaker as the old unit.”
The circuit must match the actual model and its requirements.
R-454B and A2L equipment
The MIDEA28 series uses R-454B, an A2L refrigerant.
The Midea range also incorporates features associated with this new generation of equipment, including A2L refrigerant leak detection and a dispersion system on the applicable models.
For the owner, this has little impact on day-to-day use.
For our technicians, this means that installation, refrigerant connections, leak testing, evacuation, and service work must be carried out using appropriate methods.
A quiet heat pump is especially appreciated in a small room
The photograph gives the impression of a relatively compact room. In this type of environment, the noise from a wall-mounted unit can quickly become noticeable.
The indoor sound levels published by Midea go down to approximately 19.5 dB(A) for the 9,000 and 12,000 BTU versions, depending on the operating mode. The other capacities vary according to the requested airflow.
The series also has a silent mode.
However, we pay just as much attention to the installation as to the figure announced by the manufacturer. Improper mounting or a line vibrating against a building component can create noise that has nothing to do with the fan itself.
More precise control with “Follow Me”
The MIDEA28 is one of the series offering the “Follow Me”.
With this function, the sensor built into the remote control can measure the ambient temperature at its location and allow the heat pump to adjust its operation based on that value.
This option may be useful when the unit is installed high on a wall.
The temperature near the ceiling is not always exactly the same as the temperature felt at occupant level, especially in heating mode.
However, simply keep the remote control in a representative area, not directly in the sun, near a cold window, or another heat source.
A series designed to facilitate truly thorough cleaning
Midea states that the series MIDEA35, MIDEA28, and MIDEA25 are designed with a removable blower wheel to facilitate cleaning the inside of the unit.
This feature is very important in our work.
After several air-conditioning seasons, cleaning only the filters is not always enough. Dust and deposits can accumulate on:
- the heat exchanger;
- the blower wheel;
- the condensate pan;
- the internal surfaces;
- the drain.
Good mechanical design therefore makes it easier toHVAC maintenance in the long term.
Rebates: start with the AHRI number, not just the MIDEA28 name
The AHRI numbers published for the different MIDEA28 units are:
- 215471380 — 9,000 BTU;
- 215471381 — 12,000 BTU;
- 215471382 — 18,000 BTU;
- 215471383 — 24,000 BTU;
- 215471384 — 33,000 BTU.
The brochure confirms these references as well as the classification Cold Climate V6.1, but it does not, on its own, establish the current rebate amount applicable to this specific installation.
Pour toute demande de programme d’aide financière, nous vérifions donc la For any financial assistance program application, we therefore verify theexact combination
, its AHRI number, and the official criteria applicable at the time of the work.
This is much more reliable than announcing an amount simply because two systems share the name MIDEA28.
Residential warranty for the Midea range The documentation provided presents, for the residential sector, aa 12-year limited warranty on the compressor, 12 years on parts, and 10 years on labor
, subject to the terms applicable to the warranty program.
- We recommend keeping:
- the detailed invoice;
- the indoor and outdoor models;
- the serial numbers;
- the AHRI number;
- registration documents;
all documentation related to a grant application.
The mistakes we want to avoid in a compact wall-mounted installation
Installing the unit simply because it fits in the space
Clearance, maintenance, and airflow are just as important as the wall’s width.
Installing a capacity that is too large as a precaution
A heat pump must be sized for the building’s actual load.
Ignoring openings and indoor circulation
The position of the doors directly affects how the conditioned air can move.
Neglecting the drain
A heat pump that cools properly but allows water to leak indoors is not a successful installation.
Automatically reusing the old copper lines
On the MIDEA28 itself, the diameters change several times depending on the capacity.
Forgetting about future access
Filters, the heat exchanger, fan, and drain must remain accessible for maintenance.
A discreet installation in Très-Saint-Rédempteur that makes smart use of the available space The final photograph mainly shows a.
white MIDEA28 cleanly installed in the upper part of the wall
It leaves the mirror below unobstructed, does not block the adjacent opening, and uses a location that allows the airflow to move directly toward the occupied area.
But behind this result are sizing, structural verification, drainage, refrigerant lines, electrical work, clearances, commissioning, and future access. The MIDEA MIDEA28 wall-mounted heat pump offers a particularly flexible range: five capacities from 9,000 to 33,000 BTU, with heating down to-30 °C R-454B, with efficiency of up to 27.4 SEER2 and various comfort-control functions.
At AirGreen, our work in Très-Saint-Rédempteur consists of turning these technical specifications into an installation that truly works with the home.
This same attention to sizing, positioning, and finishing accompanies our projects wall-mounted heat pumps in Montréal, Laval, Longueuil, the North Shore and the South Shore The machine matters, but the quality of its integration into the building matters just as much.