In Saint-Polycarpe, an MIDEA28 installation where the available space required a genuine positioning strategy
This MIDEA MIDEA28 wall-mounted heat pump installation in Saint-Polycarpe represents exactly the kind of job where equipment selection is only part of the work. The photograph shows a dense interior space: a large unit or refrigerated room occupies nearly the entire left side, shelves loaded with containers and equipment are on the right, a ladder is needed to access the upper parts of the room, and several existing pipes already run along the walls.
In this configuration, we did not have a large, empty wall offering several installation options. The indoor unit MIDEA28 was therefore positioned high on the wall, in an area that allows the wall space to be used without further reducing the available floor storage area.
The result is particularly interesting from an HVAC perspective: the unit is located above the circulation and storage area, with its front and air outlet unobstructed. The connections follow the wall rather than encroaching on usable space. This is a concrete way to show why, at AirGreen, we always analyze the room before deciding on the final location of a wall-mounted heat pump.
The photo does not make it possible to confirm the exact commercial use of the room or the precise BTU capacity of the installed system. We therefore do not want to invent this information. However, it clearly shows the physical constraints that our installation had to accommodate: limited height, existing equipment, shelving, visible pipes, and the need to maintain functional circulation in an already crowded space.
Positioning the wall-mounted head where it does not compromise storage
In a room used intensively for storage, every section of wall matters.
Installing a heat pump too low would have several consequences:
- loss of space for shelves and equipment;
- increased risk of impact from moved equipment;
- partially blocked airflow;
- less convenient access to storage areas;
- greater exposure to the room’s daily activities.
We therefore used the upper part of the wall.
This strategy aligns well with the principle of a ductless systemMidea indicates that the indoor unit can be connected to the outdoor unit through a relatively compact passage, without requiring the addition of an air duct network in the room. The documentation presents this type of solution as flexible for different areas of a building.
In a room like the one shown in the photograph at Saint-Polycarpe, this advantage takes on its full meaning: the space is already occupied by several installations and structures, and adding bulky ducts would have been much more intrusive.
A heat pump installed high up must nevertheless be able to breathe
Installing the unit near the ceiling is sometimes the best solution, but that never means it should be wedged into the first available space.
An indoor unit draws in ambient air, passes it over its heat exchanger, and then redistributes that air throughout the room. The air return must therefore remain unobstructed, and the outlet must not be blocked by a shelf, beam, or stored objects.
The photograph shows precisely that the front discharge of the MIDEA28 remains clear, even though the space around the unit is relatively crowded.
This is particularly important here because the room contains tall shelves. When planning this type of installation, we must consider not only what is present on the day of the work, but also what might be moved or added later.
A heat pump should not end up behind a stack of boxes or facing a shelf filled to the ceiling.
Exposed piping: prioritizing a functional route in a technical room
The photograph also shows part of the pipes running along the wall beneath the unit.
In a highly visible residential room, we can often seek to conceal the connections more fully. In a workspace or storage area like this one, the priority may be different: to achieve a short, accessible, and technically coherent route, while avoiding interference with the other equipment.
A visible pipe is not necessarily a poor installation. What matters more is that it is properly supported, protected, and routed without creating a problematic slope for the drain or unnecessary strain on the refrigerant lines.
The presence of other equipment completely changes the planning
One of the most interesting aspects of this installation in Saint-Polycarpe is the amount of equipment already present.
We can see:
- a large refrigerated or insulated structure on the left;
- several vertical pipes;
- a wall opening or duct beneath the heat pump;
- metal shelves on the right;
- many bins and containers;
- nearby work surfaces and plumbing or ventilation components.
In such an environment, drilling into a wall without prior analysis would be a poor approach.
Before an HVAC installation, we must consider what may be behind the surfaces: pipes, wiring, structures, existing equipment, and the routes of the various mechanical systems.
This is precisely what distinguishes a space that merely appears available from one that can actually be used.
The MIDEA28: a wall-mounted heat pump designed for cold climates and available in five capacities
A range from 9,000 to 33,000 BTU
Unlike the MIDEA35, which is offered in a more limited number of capacities in the brochure provided, the MIDEA28 covers a very broad range.
The technical table on page 11 presents five combinations:
- 9,000 BTU : MSEHU-H09B-2A with MO1HS-H09B-2A, AHRI 215471380;
- 12,000 BTU : MSEHU-H12B-2A with MO1HS-H12B-2A, AHRI 215471381;
- 18,000 BTU : MSEHU-H18B-2A with MO1HS-H18B-2A, AHRI 215471382;
- 24,000 BTU : MSEHU-H24B-2A with MO1HS-H24B-2A, AHRI 215471383;
- 33,000 BTU : MSEHU-H33B-2A with MO1HS-H33B-2A, AHRI 215471384.
The indoor photograph does not make it possible to read the model number with enough certainty to identify which of these capacities was installed in Saint-Polycarpe. We therefore prefer to present the exact range rather than estimate the capacity based on the apparent width of the wall-mounted indoor unit.
This clarification is important for any owner or manager comparing quotes: MIDEA28 refers to a series, not a specific BTU rating.
Heating down to -30 °C across the entire documented series
One of the most relevant characteristics of the MIDEA28 for Quebec is its operating range.
The documentation indicates that all five capacities can operate in heating mode down to -30 °C, and the configurations are identified as Cold Climate V6.1.
In Saint-Polycarpe, this feature makes it possible to use the heat pump well beyond the summer air-conditioning periods.
A unit capable of continuing to operate during very low winter temperatures can make a significant contribution to heating, provided, of course, that its capacity has been properly selected for the space's actual heat load.
However, the minimum operating temperature must never be confused with constant capacity.
A heat pump does not necessarily provide the same amount of heat at -25 °C as it does at +5 °C.
What the MIDEA28 can deliver at -15 °C
The Midea table provides much more meaningful data: the rated heating capacity at -15 °C.
Depending on the configuration:
- 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.
This data is particularly useful when we evaluate a heat pump for a Quebec building.
They also show why the choice of the number of BTUs should not be made solely on the basis of the machine's commercial name or a simplified rule based on floor area.
Up to 27.4 SEER2 and 13.5 HSPF2
The MIDEA28 also offers good seasonal efficiencies, which vary according to capacity.
The SEER2 values indicated are:
- 27.4 for the 9,000 BTU;
- 25.4 for the 12,000 BTU;
- 21.4 for the 18,000 BTU;
- 21.0 for the 24,000 BTU;
- 19.5 for the 33,000 BTU.
The HSPF2 IV, meanwhile, reaches 13,5 for the 24,000 BTU configuration, while the other capacities are listed at 12.5, 10.5, 11.0, and 10.5 depending on the model.
This recalls an important principle: when a manufacturer states “up to 27.4 SEER2,” that figure corresponds to the series' best configuration and not automatically to all MIDEA28 capacities.
Variable-speed technology suited to a space with changing needs
Midea's variable-speed technology allows the compressor to adjust its operation according to heating or cooling needs instead of operating solely according to a full-power/on-off logic.
Midea indicates that this modulation helps reduce temperature fluctuations and maintain more consistent comfort.
In a space like the one photographed in Saint-Polycarpe, thermal loads can change throughout the day.
Opening a door, operating other equipment, the presence of people, or outdoor conditions can quickly change the heating or cooling demand.
A variable-speed system can better adjust its output to these changes.
Airflow that increases significantly with capacity
The capacity choice also directly influences the volume of air moved by the indoor unit.
For the MIDEA28, the published maximum airflow increases from approximately 441 CFM for the smaller capacities to 865 CFM for the 33,000 BTU model.
In a relatively narrow or crowded room, this information matters enormously.
A larger heat pump does not only mean more BTUs. It also means a larger indoor unit and a higher airflow rate.
That is why heat pump sizing must take into account the shape of the room, the distance available for the airflow, and existing obstacles.
Very different indoor dimensions depending on capacity
The published dimensions confirm this difference.
The 9,000 and 12,000 BTU indoor units measure approximately 31.30 in. wide, while the 18,000 BTU model measures 37.99 in. and the 24,000 and 33,000 BTU models measure approximately 44.88 in..
At the photographed job site, where the unit had to fit between several structural constraints and existing installations, knowing these dimensions before ordering is essential.
A location that can accommodate a 31-inch head will not necessarily properly accommodate a unit nearly 45 inches long.
An indoor sound level suited to occupied spaces
The range also offers relatively low sound levels at reduced speeds.
Depending on the model, Midea lists minimum values ranging approximately from 16 to 29.5 dB(A) in the quietest published modes.
In a workspace, quiet operation can be especially appreciated when a heat pump needs to run for long periods.
However, we always emphasize that the actual sound level depends on the required capacity, fan speed, and room acoustics.
Refrigerant lines change with each capacity
Another reason why we need to know the exact model before installation concerns the line diameters.
For the MIDEA28:
- 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..
It would therefore be incorrect to assume that existing piping is automatically suitable for all MIDEA28 units.
In a room where several lines are already present, as in our Saint-Polycarpe photo, this check becomes even more important.
Up to 164 feet of refrigerant line length
The maximum lengths also increase according to capacity:
- 82 ft for the 9,000 and 12,000 BTU versions;
- 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 useful when the outdoor unit must be placed far from the indoor head.
Nevertheless, we always try to avoid unnecessary length when the building allows a more direct route.
A 208/230 V power supply, but with different electrical requirements
All documented MIDEA28 configurations operate with a 208/230 V, single-phase, 60 Hz.
The outdoor unit requirements nevertheless vary considerably.
The published minimum allowable ampacity is:
- 15 A for the 9,000 BTU model;
- 15 A for the 12,000 BTU model;
- 19 A for the 18,000 BTU model;
- 24.9 A for the 24,000 BTU model;
- 34 A for the 33,000 BTU model.
The maximum overcurrent protection ratings increase respectively from 15 A to 35 A depending on the capacity.
That is why we always check the available circuit before confirming an installation.
R-454B and A2L system
The MIDEA28 uses R-454B refrigerant.
The MIDEA28 range is also part of the series that the brochure associates with an A2L dispersion system, a smart sensor, humidity control, and various comfort management functions.
For us, HVAC installers, the transition to A2L refrigerants means that commissioning procedures, tools, and practices must be adapted to this equipment.
The owner or manager does not need to master all the technical details of R-454B, but must ensure that their contractor is familiar with the requirements specific to this new generation of heat pumps.
Useful features when the heat pump has to operate for long periods
The MIDEA28 includes several features that may be useful in a regularly occupied space:
- fan speed control 1% to 100%;
- ECO mode;
- night mode;
- silent mode;
- timer;
- “Follow Me” function;
- horizontal swing;
- vertical swing;
- automatic cleaning;
- 8°C heat maintenance;
- smart sensor;
- humidity control;
- optional wired control;
- Wi-Fi control.
Midea also indicates that the wall-mounted unit offers up to 100 airflow adjustment levels.
In a space where users do not want to constantly receive maximum output, this precision can significantly improve comfort.
Maintenance had to be considered from the moment the location was chosen
The photo clearly shows why future maintenance is important.
A ladder is already required to reach the unit, and the room contains a great deal of equipment. We must therefore preserve a sufficiently accessible area below and in front of the heat pump.
The MIDEA28 has another advantage: Midea indicates that the indoor unit’s ventilation wheel can be removed to facilitate deep cleaning.
Good accessibility nevertheless remains essential.
A heat pump installed too close to a fixed structure can make even the best maintenance design useless if the panels can no longer be opened.
Subsidies: the exact AHRI reference remains essential
The Midea brochure provides the five AHRI references for the MIDEA28, but it does not specify the amount of financial assistance applicable to this particular Saint-Polycarpe installation.
We therefore cannot assign a subsidy amount to this project based solely on the photo and this brochure.
Any eligibility verification must be carried out using:
- the exact indoor model;
- the exact outdoor model;
- the AHRI number;
- the capacity;
- the installation date;
- the applicable program conditions.
This method avoids presenting financial assistance as guaranteed when it could apply to another configuration in the same series.
This Saint-Polycarpe project shows why the installation must adapt to the building
This installation of a MIDEA MIDEA28 wall-mounted heat pump in Saint-Polycarpe is not interesting simply because the unit is mounted very high on a wall.
It is interesting because the wall was already surrounded by constraints.
On the left, a large structure occupies a significant portion of the room. On the right, shelves use almost all the available height. Existing ducts and installations cross the room. The floor must remain available for circulation and storage.
In this environment, our job is to integrate the heat pump without turning the space into another obstacle.
The MIDEA28 offers a particularly broad capacity range, from 9,000 to 33,000 BTU, heating operation down to -30 °C, R-454B refrigerant, and efficiencies of up to 27.4 SEER2.
But these features can reach their full potential only if the indoor unit can properly draw in air, distribute its airflow without obstruction, drain its condensate, and remain accessible for maintenance.
This is precisely what we seek to achieve at AirGreen in our wall-mounted heat pumps in Saint-Polycarpe, but also in Montréal, Laval, Longueuil, on the North Shore and on the South Shore : select the equipment based on the needs, then adapt the installation to the building’s actual constraints rather than forcing the building to adapt to the machine.