In Sainte-Marthe, a MIDEA28 installed between a door and a window to preserve usable wall space and distribute air more effectively
This MIDEA28 wall-mounted heat pump installation in Sainte-Marthe illustrates a challenge we regularly encounter in homes where the truly available wall space is much more limited than it appears on a floor plan. Between doors, windows, curtain rods, furniture, and architectural features, finding the right location for an indoor unit sometimes requires as much thought as choosing the heat pump itself.
In the photograph taken after our work, the situation is very clear. We installed the indoor unit MIDEA28 in the upper part of a wall, between a door opening on the left and a large window on the right. The wall-mounted unit is also located beneath a ceiling soffit, in a room whose height and architectural lines made positioning particularly important.
The result is compact and orderly. The heat pump occupies a space that was difficult to use for furniture, while leaving the lower part of the wall available. The curtain remains independent of the unit, the door opening is unobstructed, and the airflow flap can distribute air directly into the room.
That is precisely what we look for at AirGreen: use the existing space intelligently rather than forcing an installation into a location simply because it seems easier for routing the lines.
The photo shows a very concrete space constraint
The chosen wall was not completely unobstructed.
On the left, there was a door with its frame. On the right, a large window with a curtain rod and a curtain descending almost to the level of the unit. Above, the ceiling configuration formed a pronounced architectural line.
Therefore, it was necessary to position the wall-mounted heat pump precisely.
A few inches of movement to the right would have unnecessarily brought the unit closer to the curtain. Moving it too far to the left would have created a less interesting visual and functional relationship with the door opening. Installing it too high would have reduced the available head clearance.
We therefore sought a balanced position that would allow:
- proper air intake through the upper part of the unit;
- full opening of the air outlet louver;
- a reasonable distance from the curtain;
- future access to the filters;
- enough space forHVAC maintenance;
- air distribution toward the center of the room;
- a clean integration with the ceiling and wall lines.
It is an installation that appears simple once completed, but its quality depends directly on the decisions made before the first hole is drilled.
Installing a heat pump near a curtain requires considering the airflow
The presence of the curtain to the right of the unit deserves particular attention.
A textile placed too close to a wall-mounted head can move under the effect of the airflow or end up in an area where it partially obstructs intake or distribution.
We therefore maintained a gap between the unit and the curtain.
This precaution is important in several types of properties, especially when the unit must be installed:
- between two windows;
- near a patio door;
- above a window;
- in a bedroom with long curtains;
- in a living room where the wall surfaces are already occupied.
The best location for a wall-mounted air conditioner or heat pump is not necessarily the emptiest wall. Instead, look for the location that will allow the system to distribute its air properly while remaining practical for everyday use.
A head installed very high must still be able to draw in enough air
In the photo from Sainte-Marthe, the MIDEA28 is installed in the upper part of the wall.
This position frees up the lower space, but it requires an essential check: the upper air intake must not be obstructed by the ceiling.
A wall-mounted unit draws in ambient air, passes it through its filters and heat exchanger, then redistributes it throughout the room.
If the space available above the unit is inadequate, this can complicate:
- air circulation;
- opening the panel;
- filter removal;
- cleaning operations;
- certain technical interventions.
We therefore incorporate this consideration from the measurement stage.
The visible display also confirms that it has been turned on
In the final photo, the unit’s digital display is on and shows 60.
The MIDEA allows you to select a display in degrees Celsius or Fahrenheit. The series documentation specifically indicates the function for switching between °C and °F, as well as the option to enable or disable the LED display using the remote control.
A photograph alone cannot confirm the exact mode being used when it was taken, but the illuminated display shows that the unit had been powered on and operating during the final inspection.
Why the MIDEA28 is attractive for Sainte-Marthe residences
The MIDEA28 is presented by MIDEA as a premium wall-mounted series designed for cold climates.
It operates with R-454B refrigerant, is identified as Cold Climate V6.1, can operate in heating mode down to -30 °C and reaches up to 27.4 SEER2 in cooling mode and up to 13.5 HSPF2, depending on the selected capacity.
For a house of Sainte-Marthe, this makes it possible to consider the unit a true heating and cooling solution rather than simply an air conditioner used a few weeks per year.
Low-temperature performance is particularly important in Quebec, since the heat pump must continue operating as the heating demand increases significantly.
The MIDEA28 is available in five different capacities
It is important to clarify that “MIDEA28” refers to a series, not a single capacity.
The MIDEA brochure presents five combinations:
| MIDEA28 combination | Rated cooling | Rated heating | SEER2 | HSPF2 IV | AHRI reference |
|---|---|---|---|---|---|
| MSEHU-H09B-2A / MO1HS-H09B-2A | 9,000 BTU/h | 12,000 BTU/h | 27,4 | 12,5 | 215471380 |
| MSEHU-H12B-2A / MO1HS-H12B-2A | 12,000 BTU/h | 12,000 BTU/h | 25,4 | 10,5 | 215471381 |
| MSEHU-H18B-2A / MO1HS-H18B-2A | 18,000 BTU/h | 18,000 BTU/h | 21,4 | 11,0 | 215471382 |
| MSEHU-H24B-2A / MO1HS-H24B-2A | 24,000 BTU/h | 29,000 BTU/h | 21,0 | 13,5 | 215471383 |
| MSEHU-H33B-2A / MO1HS-H33B-2A | 33,000 BTU/h | 36,000 BTU/h | 19,5 | 10,5 | 215471384 |
The five combinations are listed as capable of operating in heating mode down to -30 °C.
However, the photograph of the indoor unit installed in Sainte-Marthe does not allow us to read its model number with certainty.
Even if the head unit appears relatively compact, we cannot determine the exact BTU rating from its appearance alone.
For us, the complete combination always remains the valid reference indoor unit + outdoor unit + AHRI number.
Why we avoid choosing BTUs based solely on floor area
A quick calculation based solely on the number of square feet can provide an initial indication, but it does not by itself constitute a serious sizing assessment.
We also examine:
- the insulation characteristics;
- the quality of the windows;
- the number of exterior walls;
- solar orientation;
- the ceilings;
- the openings between rooms;
- the building’s heat loss;
- the floor where the unit will be installed;
- how the air will be able to circulate.
In this installation Sainte-Marthe, positioning the indoor unit in an area open to the room is just as important as its rated capacity.
A unit may have sufficient BTUs on paper, but if its airflow is directed at an obstacle or confined to a poorly chosen section of the room, actual comfort may fall short of expectations.
Compressor modulation plays an important role in comfort
The MIDEA range uses variable-speed technology.
The manufacturer states that the compressor continuously adjusts its operation according to demand rather than simply alternating between on and off. This modulation reduces indoor temperature fluctuations and provides more stable operation.
In practice, this means that the heat pump can reduce its output as the room approaches the desired temperature.
This capability also helps explain why oversizing is undesirable.
We want the heat pump to be able to use its modulation range and operate steadily rather than reaching the setpoint too quickly and shutting off.
Up to 100 fan speed levels for adjusting airflow
MIDEA documentation indicates up to 100 airflow volume adjustment levels across this family of systems.
This feature is particularly relevant in a room like the one shown in the photograph.
The indoor unit is located relatively high and near a window. Being able to finely adjust the airflow and direction makes it possible to seek a better balance between:
- heating or cooling speed;
- perceived air movement;
- temperature uniformity;
- noise level.
The louvers also provide horizontal and vertical oscillation, depending on the series features.
Behind this discreet indoor installation: the MIDEA28 technical details that matter over the long term
The Follow Me feature is useful when the unit is located near the ceiling
A heat pump installed high on a wall may measure a different temperature from the one felt lower down in the room.
This is particularly true in heating mode, since warm air naturally tends to rise.
The feature Follow Me uses the sensor built into the remote control to measure the ambient temperature where it is located. MIDEA can then use this information to adjust its operation more precisely.
In a room like this one in Sainte-Marthe, this feature can be useful when the remote control is placed in a representative area of the space actually being occupied.
Smart sensor and humidity management
The MIDEA28 is one of the series for which the brochure mentions a smart sensor as well as dual temperature and humidity control.
MIDEA also indicates that its smart sensor can take activity in the room into account. When the space remains unoccupied for more than 30 minutes, the unit can reduce its operating frequency to limit consumption.
This type of feature may be useful in a room used variably throughout the day.
Silence is important in a residential room
The MIDEA28 offers different indoor sound levels depending on capacity.
The brochure notably lists minimum values of approximately:
- 19.5 dB(A) for the 9,000 BTU model;
- 19.5 dB(A) for the 12,000 BTU model;
- 19.5 dB(A) for the 18,000 BTU version;
- 16 dB(A) for the 24,000 BTU model;
- 29.5 dB(A) for the 33,000 BTU model,
depending on the modes and conditions specified by the manufacturer.
These figures obviously do not mean that the unit operates constantly at its lowest level.
When demand is high, the fan increases its speed. The benefit of modulation becomes most apparent once the temperature has stabilized.
Future maintenance should already have been considered when choosing the height
A unit installed like this, near a ceiling soffit, must remain accessible.
The filters will need to be removed and cleaned regularly. Over time, the evaporator and blower wheel may also require more thorough cleaning.
MIDEA indicates that, for the MIDEA35, 28, and 25 series, the The blower wheel can be removed to facilitate deep cleaning inside the unit.
This feature is a real advantage only if the installer leaves enough space around the unit to allow servicing.
That is why we do not look only at what is aesthetically pleasing on the day of installation. We also think about the future heat pump maintenance.
Copper diameters change considerably depending on capacity
The MIDEA28 is an excellent example of the importance of checking the model number before installing or replacing a heat pump.
The refrigerant pipes therefore vary:
- 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..
When replacing a unit, we therefore cannot simply connect a new unit to the existing pipes without checking their compatibility.
The maximum lengths also vary
Depending on the MIDEA28 capacity, the maximum pipe length can be:
- 82 ft for the 9,000 and 12,000 BTU models;
- 98.4 ft for the 18,000 BTU version;
- 164 ft for the 24,000 and 33,000 BTU versions.
The permitted height difference can reach up to 82 ft for the larger configurations.
These options provide flexibility when the outdoor unit must be located farther from the indoor head, but they must be considered alongside the requirements of the model actually installed.
R-454B throughout the MIDEA28 series
The five MIDEA28 combinations in the brochure use R-454B.
This refrigerant belongs to the A2L category. The range also includes devices related to the management and detection of A2L refrigerant.
For the owner, this technology remains transparent in daily use.
For our team, it means that theHVAC installation, commissioning and service work must be carried out using methods and equipment suited to the system.
The electrical requirements also depend on the exact model
All the MIDEA28 models listed in the brochure operate on 208/230 V single-phase, 60 Hz, but their protection requirements differ.
According to the capacity:
- 9,000 BTU: minimum ampacity 15 A, maximum protection 15 A;
- 12,000 BTU: minimum ampacity 15 A, maximum protection 15 A;
- 18,000 BTU: minimum ampacity 19 A, maximum protection 20 A;
- 24,000 BTU: minimum ampacity 24.9 A, maximum protection 25 A;
- 33,000 BTU: minimum ampacity 34 A, maximum protection 35 A.
This shows why the choice of breaker and conductors must always be based on the technical specifications for the exact combination.
The features that the owner will actually use on a daily basis
Beyond BTUs and performance coefficients, the MIDEA28 offers several useful features:
- ECO mode;
- Turbo mode;
- night mode;
- timer;
- child lock;
- Follow Me;
- automatic cleaning;
- quiet mode;
- heating at 8°C;
- horizontal swing;
- vertical swing;
- fan adjustment from 1% to 100%;
- humidity control;
- smart sensor;
- Wi-Fi control and wired control options.
Heating at 8°C can be used, among other things, to maintain a minimum temperature in a property left unoccupied during a cold period.
LogisVert: always verify the combination, not just “MIDEA28”
When we carry out a heat pump installation in Sainte-Marthe, the question of financial assistance is often part of the comparison.
The documentation provided clearly establishes the AHRI numbers the different MIDEA28 models and their Cold Climate V6.1 classification.
However, this brochure does not provide a LogisVert amount applicable to this specific installation.
We therefore avoid automatically associating a rebate with a photo or the simple name of the product line.
To determine an eligible amount, it is necessary to confirm, among other things:
- the exact indoor model;
- the exact outdoor model;
- the AHRI number;
- the relevant capacity recognized by the program;
- the required certification;
- the installation date;
- the conditions specific to the home.
This is the only way to avoid an inaccurate estimate.
Mistakes to avoid in an interior installation like this one
This Sainte-Marthe installation illustrates several common mistakes:
- placing the indoor unit too close to the ceiling;
- not leaving enough space to open its panel;
- installing the unit too close to a curtain;
- blowing air directly onto the area where occupants sit;
- choosing the location solely according to the easiest route for the copper lines;
- determining the BTU capacity based solely on floor area;
- neglecting drainage;
- using an old line set without checking the diameters;
- ignoring future access for maintenance;
- selecting the electrical circuit without consulting the model specifications.
A successful installation involves resolving these constraints before they become problems.
An integration that truly respects the room
This Sainte-Marthe project Sainte-Marthe is a good representation of what we seek in our AirGreen installations.
The MIDEA28 indoor unit is visible, like any wall-mounted heat pump, but it does not unnecessarily intrude into the room. It occupies an area between the door and the window that would have been difficult to use otherwise.
The wall remains available for furniture and décor. The curtain can function normally. The door frame remains unobstructed. The unit is positioned high enough to distribute air throughout the room while maintaining the necessary access for maintenance.
We apply this same method in our HVAC installations in Montreal, Laval, Longueuil, on the North Shore, and on the South Shore, as well as in the municipalities of Vaudreuil-Soulanges and the surrounding areas.
A heat pump should not be installed solely where it is easiest to connect.
It must be installed where the building, occupant comfort, air circulation, and future maintenance can work together.
In this Sainte-Marthe home, the MIDEA28 fits precisely into a section of wall made complicated by the presence of a door, a window, and an unusual ceiling. The final result remains clean, balanced, and suited to daily use throughout Quebec’s four seasons.