Installation of a MIDEA35 12,000 BTU Wall-Mounted Heat Pump in Charlemagne: A Compact, Clean, and Efficient Solution for a Well-Appointed Residential Space
AirGreen installs a MIDEA35 12,000 BTU wall-mounted heat pump in Charlemagne: compact mini-split, meticulous installation, efficient comfort, and residential HVAC expertise.
Take a tour of the installation
Each number is a point we check on site. Switch between summer and winter to watch air and heat move.
In summer, the outdoor unit rejects the house's heat outside.
Generic illustration of this type of installation, not a survey of this job site. Tap a number.
Mounted level on a wall plate, high enough for the air to reach the whole room, with enough space around it to slide the filters out easily.
The refrigerant lines, the communication cable and the drain go through the wall in a single opening, sealed against water, cold air and insects.
Two insulated copper pipes connect the two units. Outside, a line cover can protect them from sun, knocks and weather.
A shut-off switch near the outdoor unit isolates it safely for service. It must stay accessible at all times.
The compressor and the fan. In heating mode it captures heat from the outdoor air, even in winter, and moves it inside.
On the ground or on the wall, it keeps the unit above accumulated snow. The unit stays clear and defrost water can drain away.
The fan needs to blow freely. Storage, a fence or a wall too close, and efficiency drops while noise goes up.
A discreet HVAC installation in a space where every detail counted
In Charlemagne, our AirGreen team recently completed the installation of a MIDEA35 12,000 BTU wall-mounted heat pump, a wall-mounted air conditioner – mini split type unit designed to offer stable, efficient, and quiet comfort in a residential environment where available space had to be utilized precisely.
This installation perfectly illustrates a common reality in homes, condos, and apartments in the Montreal, Laval, Longueuil, North Shore, and South Shore regions: the choice of a heat pump is never limited to BTU power. It must also consider the indoor location, air circulation, architectural constraints, the routing of refrigerant lines, the final aesthetics, and the ease of access for future HVAC maintenance.
In this project, the wall unit was installed high up, near the ceiling, in a confined but strategic space. The photo clearly shows a compact installation, with a Midea indoor unit positioned above a passageway and near a side wall. This type of configuration requires particular attention: the appliance must be sufficiently clear to ensure good air diffusion, while respecting the technical clearances required for the system's operation, maintenance, and durability.
Why a MIDEA35 12,000 BTU was suitable for this project in Charlemagne
The MIDEA35 12,000 BTU is a very relevant solution when a client is looking for a good balance between comfort, energy efficiency, compact size, and reasonable installation cost. For a living room, a partially open floor, a condo, or a well-insulated residential area, a capacity of 12,000 BTU can offer excellent coverage when the sizing is well-evaluated on-site.
At AirGreen, we always avoid recommending a machine based solely on approximate surface area. During our evaluations, we analyze several concrete elements:
- the building's orientation and sun exposure;
- the level of insulation;
- ceiling height;
- the presence of large windows;
- room configuration;
- natural air circulation;
- the client's heating and cooling habits;
- the possible location of the outdoor unit;
- drainage and piping constraints.
In this specific case in Charlemagne, the MIDEA35's wall-mounted format integrated very well into the available space. The high installation allowed for effective air distribution without encroaching on the interior layout. The client wanted a solution that was both practical and discreet, with no major visible interior work. This is exactly the kind of mandate where our experience in HVAC installation becomes essential.
A well-positioned indoor unit to optimize air distribution
The wall unit visible in the image is installed near the ceiling, in a location that allows air to be projected into the area to be treated. This choice is never left to chance. A poorly positioned wall-mounted heat pump can create cold spots, uncomfortable drafts, or lower performance than the unit can actually offer.
In this installation, we paid particular attention to three aspects:
Clearance around the unit
Even if the space is compact, the unit had to maintain sufficient clearance to draw in ambient air and redistribute it correctly. A wall-mounted heat pump works by continuously analyzing the room temperature. If the unit is too cramped, too close to an obstruction, or installed at an improper angle, the temperature reading can be inaccurate.
Refrigerant line routing
The photo shows the insulated routing of the piping on the right side of the unit. This part of the installation is crucial. The lines must be protected, adequately insulated, and installed to avoid efficiency losses, undesirable condensation, or vibrations. A clean finish around the unit also contributes to the system's durability and the overall appearance of the installation.
Access for future service
A good installation is not just judged on the day of commissioning. It must also allow reasonable access for filter cleaning, inspection, drain verification, and future technical interventions. At AirGreen, we always consider HVAC maintenance from the initial installation, because a well-maintained heat pump retains better performance in the long term.
A Midea wall unit designed for daily comfort
The MIDEA35 12,000 BTU belongs to a category of wall-mounted systems appreciated for their modulating operation, their cooling comfort, and their ability to maintain a more stable temperature than a traditional on-off system. In a residence, this translates to more constant comfort, fewer abrupt variations, and generally quieter operation.
For a client in Charlemagne, the goal was not simply to add an air conditioning unit. It was about installing a complete solution capable of improving indoor comfort during warm periods, while offering an efficient heating option during cooler seasons. A well-sized wall-mounted heat pump often allows for reduced use of more energy-intensive auxiliary systems, depending on the house configuration and usage habits.
Technical peculiarities observed in this installation
The visible label on the unit confirms that it is a Midea appliance, with the certification and safety information specific to this type of equipment. Also notable is the mention related to the new generation refrigerant, with A2L signaling. This detail is important, as modern equipment requires installation compliant with applicable standards and carried out by qualified professionals.
At AirGreen, our technicians comply with the requirements specific to systems using modern refrigerants. This includes:
- proper handling of refrigerant lines;
- the use of appropriate tools;
- adherence to sealing procedures;
- drainage verification;
- controlled startup;
- validation of operating parameters;
- client awareness of safe and efficient appliance use.
This type of rigor is essential for any wall-mounted heat pump installation in Montreal, Laval, Longueuil, on the North Shore, or on the South Shore, but it becomes even more important when the unit is installed in a compact indoor space where the finish must be clean and durable.
Challenges encountered during this installation in Charlemagne
Even when a project seems simple at first glance, a wall installation often requires several on-site adjustments. In Charlemagne, the main challenge came from the available interior space and the proximity to the ceiling, the side wall, and existing elements in the room.
Working cleanly in a confined space
The photo shows an already furnished interior area, with storage elements and limited circulation around the unit. In this type of context, our team must work carefully to protect surfaces, avoid marks on walls, and ensure a clean finish around the passage of ducts.
A common mistake in this type of project is to install the unit too quickly without properly planning the routing of refrigerant lines and the drain. This can lead to a less aesthetic installation, maintenance difficulties, or condensation problems. Our approach is to validate the complete routing before the final fixing of the unit.
Ensuring reliable drainage
Drainage is one of the most important aspects of a wall-mounted air conditioner or wall-mounted heat pump. In cooling mode, the indoor unit produces condensation that must be properly evacuated. If the drain slope is insufficient or if the passage is poorly planned, the client may eventually experience leaks, odors, or operational shutdowns.
On this project, we paid particular attention to the positioning of the drain and the continuity of the evacuation path. This is an invisible detail when everything works well, but it makes all the difference in the durability of an installation.
Preserving interior aesthetics
A client installing a wall-mounted heat pump wants comfort, but they also want the result to be visually acceptable. A crookedly installed unit, misaligned ducts, or an approximate finish can quickly detract from the overall appearance of the room.
In this Midea installation in Charlemagne, the objective was to achieve a clean integration, with a well-leveled unit, properly insulated ducts, and a discreet final result. Even in a technical or secondary space, our team applies the same standards as for an installation in a main living room, bedroom, or open area.
Mistakes to avoid when installing a 12,000 BTU wall-mounted heat pump
Many homeowners compare models online before choosing a heat pump. This is a good approach, but actual performance depends heavily on the installation. For a 12,000 BTU unit, certain errors can reduce comfort and performance.
Choosing power without on-site evaluation
A heat pump that is too small will run almost constantly without achieving the desired comfort. A unit that is too powerful can cycle too quickly, dehumidify poorly, and create a feeling of discomfort. The correct sizing depends on the room, insulation, sun exposure, openings, and air volume.
Neglecting the indoor location
Installing the unit in the wrong place can reduce its actual reach. A door, wall, beam, or too enclosed area can block air diffusion. In several projects in Montreal, Laval, and Longueuil, we have corrected existing installations where the unit was functional but poorly placed from the start.
Underestimating the importance of duct insulation
Refrigerant lines must be well insulated to limit losses, prevent condensation, and protect the system. Negligent insulation can lead to moisture traces or a loss of efficiency.
Forgetting regular maintenance
Filters must be cleaned periodically. The indoor unit must also be inspected and cleaned when necessary, especially if it often operates in cooling mode. Good HVAC maintenance helps maintain air quality, airflow, and energy performance.
A client experience focused on clarity and trust
During this project in Charlemagne, our role was not limited to installing a machine. We also explained to the client how to use the heat pump efficiently, how to adjust modes, how to maintain filters, and how to spot signs that might require service.
This step is important because many users operate their appliance incorrectly after installation. For example, constantly changing the desired temperature, using only automatic mode without understanding its behavior, or closing doors between rooms can reduce the comfort achieved. We take the time to give simple and practical advice so that the client can fully benefit from their investment.
Subsidies and potential eligibility
For homeowners in Charlemagne and the surrounding areas, subsidy programs can represent a significant advantage when purchasing a wall-mounted heat pump. Eligibility depends on the exact model, current criteria, provided documentation, and the requirements of the applicable program at the time of installation.
At AirGreen, we help our clients better understand the necessary documents, including the invoice, model information, and required technical details. For an installation in the greater Montreal area, including Laval, Longueuil, the North Shore, and the South Shore, this support can make a concrete difference in preparing the file.
Why choose AirGreen for a Midea installation in Charlemagne
Our team regularly installs wall-mounted, central, and multi-zone systems in various environments: condos, single-family homes, plexes, businesses, offices, and technical spaces. This experience allows us to adapt each installation to the reality of the building, rather than applying a uniform method.
For this HVAC installation in Charlemagne, our approach was distinguished by:
- a precise analysis of the indoor location;
- a careful installation despite the confined space;
- particular attention to duct routing;
- a clean finish;
- a verified startup;
- usage advice given to the client;
- a long-term vision for maintenance and durability.
We know that a client isn't just looking for a machine. They are looking for a reliable, well-installed solution, supported by an available and experienced team. That's why every AirGreen project is treated as a complete installation, with professional follow-up and genuine attention to detail.
A compact, functional, and durable final result
This MIDEA35 12,000 BTU installation in Charlemagne demonstrates that a wall-mounted heat pump can be integrated effectively even in a limited space, provided that planning is well done. The indoor unit is positioned to offer good comfort, the duct routing is controlled, and the whole retains a clean and professional appearance.
For homeowners considering the installation of a wall-mounted air conditioner, a wall-mounted heat pump, or a mini-split system in the Montreal, Laval, Longueuil regions, on the North Shore or South Shore, this project is a good example of what to look for: a well-chosen appliance, compliant installation, meticulous finishing, and a team that understands the real constraints of the building.
At AirGreen, we continue to offer HVAC installations designed for comfort, energy efficiency, and peace of mind. This project in Charlemagne adds to our long list of successful installations, meticulously carried out throughout the greater metropolitan area.
The unit on this job, in figures
The range as published on airgreen.ca: pick a size to see its capacity in deep cold.
| Size | Heating at −8 °C | Heating at −15 °C | Coldest certified point | COP at −15 °C | SEER | HSPF | Indicative LogisVert aid |
|---|---|---|---|---|---|---|---|
| Midea Série 35 9 000 | 11,000 | 13,500 | −30 °C: 7,500 | 2.0 | 33.3 | 14.6 | – |
| Midea Série 35 12 000 | 11,000 | 13,500 | −30 °C: 7,500 | 2.0 | 29.4 | 12.7 | $1,320 |
| Midea Série 35 18 000 | 19,300 | 22,600 | −30 °C: 11,900 | 2.34 | 25.6 | 16.2 | $2,316 |
According to NEEP, its certified maximum capacity at −30 °C (−22 °F) is 7,500 BTU/h, 83% of its nominal 9,000 BTU size.
At 8 °C, its certified maximum capacity reaches 17,200 BTU/h, 91% more than its nominal 9,000 BTU size.
According to NEEP, its certified heating capacity at −15 °C (5 °F) is 13,500 BTU/h, 150% of its nominal 9,000 BTU size. Its COP there is 2.00.
According to NEEP, its certified maximum capacity at −30 °C (−22 °F) is 7,500 BTU/h, 62% of its nominal 12,000 BTU size.
At 8 °C, its certified maximum capacity reaches 17,200 BTU/h, 43% more than its nominal 12,000 BTU size.
According to NEEP, its certified heating capacity at −15 °C (5 °F) is 13,500 BTU/h, 112% of its nominal 12,000 BTU size. Its COP there is 2.00.
According to NEEP, its COP at −15 °C is 2.34: the highest of the Série 35 line, which ranges from 2.00 to 2.00 at that temperature.
According to NEEP, its certified maximum capacity at −30 °C (−22 °F) is 11,900 BTU/h, 66% of its nominal 18,000 BTU size.
At 8 °C, its certified maximum capacity reaches 29,700 BTU/h, 65% more than its nominal 18,000 BTU size.
Data read live from the airgreen.ca page of each size (NEEP / AHRI certified performance). When the title names the installed size, it is highlighted; otherwise the whole range is shown. The aid shown is today’s, using Hydro-Québec’s rule ($120 per 1,000 BTU/h at −8 °C); amounts quoted in the article date from its publication. Only Hydro-Québec confirms the assistance granted.A dash in the aid column: amount to be confirmed for this model.
The big day, step by step
The main steps of this kind of job at AirGreen. Every house has its quirks: the estimate brings them out.
We look at the room, the outside wall, the line route and where the outdoor unit will go. That is where the capacity gets chosen.
Model, capacity and price, in writing. We also check whether the model qualifies for assistance programs.
Floors and furniture protected, wall plate position marked level, wall opening located.
A single opening, with the slope the drain needs to flow outside.
Set on a stand raised above the snow, with the clearances the manufacturer requires.
Connected, insulated and protected. The opening is then sealed against water, cold air and insects.
A dedicated circuit and an accessible disconnect near the outdoor unit.
Leak test, vacuum, then start-up and a check of heating and cooling.
Remote, modes, filters: we show you the essentials before we leave.
- The on-site estimateWe look at the room, the outside wall, the line route and where the outdoor unit will go. That is where the capacity gets chosen.
- The quoteModel, capacity and price, in writing. We also check whether the model qualifies for assistance programs.
- Getting readyFloors and furniture protected, wall plate position marked level, wall opening located.
- The wall openingA single opening, with the slope the drain needs to flow outside.
- The outdoor unitSet on a stand raised above the snow, with the clearances the manufacturer requires.
- Lines, cable and drainConnected, insulated and protected. The opening is then sealed against water, cold air and insects.
- The electrical workA dedicated circuit and an accessible disconnect near the outdoor unit.
- Tests and start-upLeak test, vacuum, then start-up and a check of heating and cooling.
- The walkthroughRemote, modes, filters: we show you the essentials before we leave.
What would it look like at your place?
Two quick checks with real numbers: what heat costs, and what your current heaters add up to in BTU/h.
Baseboards and electric furnaces turn 1 kWh of electricity into 1 kWh of heat. A heat pump delivers more: that is its COP. At Hydro-Québec’s rate D (11.142¢/kWh above 40 kWh a day, since 1 April 2026):
Hydro-Québec: a heat pump can be up to three times more efficient than baseboards for heating in the colder months.
Estimate per kWh of heat, at the chosen temperature, using the certified COP from the product page. Taxes, access charge and backup heat not included.
Conversion: 1 W = 3.412 BTU/h. An indication, not a load calculation: baseboards and furnaces are often stronger than the real need, and they can stay as backup. AirGreen confirms the capacity on site.
Four mistakes we do not make
Flip each card to see what we do instead.
Your own project, step by step
What to do, season by season
Three habits per season for this unit. They take a few minutes and prevent many calls.
- Clean the indoor unit's filters.
- Clear leaves and debris left on the outdoor unit by winter.
- Test cooling before the first hot days.
- Clean the filters more often when the unit runs a lot.
- Keep plants away from the outdoor unit.
- Check that no water drips from the indoor unit.
- Rake the leaves around the outdoor unit.
- Test heating before the first cold days.
- Book periodic maintenance before winter.
- Keep snow away from the stand and the front of the unit.
- Let the unit defrost: it is normal.
- Never hit the ice on the fins; call us if the unit stays iced up.
Is your home ready?
Check what applies at your place. A "no" is not a refusal: it is what we sort out during the estimate.
Four statements: true or false?
It all comes down to details you have just seen.
1. In heating mode, the outdoor unit can produce water.
During defrost cycles. That water must drain away without forming ice.
2. You pick the capacity with a simple square-footage rule.
Windows, insulation, orientation and how the room is used all count. Capacity is chosen on site.
3. A multi-zone connects several indoor heads to a single condenser.
One head per room, all on the same condenser. Each room keeps its own temperature.
4. The disconnect can sit behind the patio furniture.
It must stay accessible: it is what shuts the unit off for service.
0 / 4 right answers
What people ask us about this kind of work
Does a wall-mounted heat pump heat in winter?
Wall-mounted or multi-zone: how do I choose?
Where does the outdoor unit go?
Are there grants?
Do I need a permit?
How cold can it heat?
How much can I save?
How is the LogisVert assistance calculated?
Is it noisy?
The outdoor unit is covered in ice: is that normal?
Does AirGreen hold the required licences?
Is the estimate free?
No question matches. Write to us: we answer.
More jobs to see, near you
By town, by equipment or by region: browse more than 4,700 published projects.
Each dot: a town where AirGreen has published projects. The glowing dot: this job.
Every house has its constraints. We see them before we install.
The on-site estimate is free and the quote follows within 24 hours.
Text and photo: a real AirGreen Climatisation & Chauffage job. The diagrams are generic illustrations of the type of installation, not a survey of this job site. Sources of the added figures: airgreen.ca product pages (NEEP / AHRI performance), Hydro-Québec (Heat pumps page, LogisVert, read on 13 October 2026), Régie de l’énergie (rate D as of 1 April 2026).