Installation of a MIDEA MIDEA28 dual-zone heat pump in Saint-Basile-le-Grand, in Montérégie on Montreal’s South Shore
In Saint-Basile-le-Grand, AirGreen installs a MIDEA MIDEA28 dual-zone heat pump in a narrow passage: outdoor installation, inverter technology, technical data, and LogisVert advice.
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A narrow outdoor passage, a brick wall, and a single unit for two zones: an installation planned down to the centimeter
In Saint-Basile-le-Grand, this installation of a MIDEA MIDEA28 dual-zone heat pump illustrates very well a type of project we regularly encounter on the South Shore of Montreal: the machine must provide effective comfort to several rooms, but the space available for installing the outdoor unit is far from unlimited.
In the construction photo, the surroundings are particularly revealing. The Midea condenser is located immediately beside a brick wall, in a passage bordered by a structure and a wooden lattice door. The lines run vertically along the masonry, and the outdoor electrical disconnect is installed within reach of the equipment. Everything therefore had to be organized without turning this functional space into a cluttered area.
For us, a good HVAC installation starts precisely there: before connecting the first line, you need to understand how the house is used, how air circulates around the machine, how a technician will be able to service it several years later, and how the occupants will continue to use their yard, patio, or passage normally.
Why a dual-zone system made sense in this Saint-Basile-le-Grand residence
A multizone heat pump makes it possible to connect several indoor units to a single outdoor unit. Each indoor unit can then be controlled separately and adjusted according to the desired temperature in the room concerned. This is exactly the principle described by Midea for its multizone platform.
In a dual-zone configuration, this means that a residence can, for example, condition separately:
- an open-plan area and a bedroom;
- the ground floor and the upper floor;
- a primary bedroom and a living area;
- a room more exposed to the sun and another located on the shaded side;
- an original part of the house and an addition.
Two zones therefore do not simply mean “two air conditioners.” The real advantage is being able to adapt heating and cooling to different loads, while keeping a single outdoor condenser.
In a residential area such as Saint-Basile-le-Grand, where many homes have a yard, side passage, or patio whose use they want to preserve, avoiding the installation of two outdoor units is a very concrete advantage.
What the photo teaches us about the quality of an outdoor installation
The unit is not located in the middle of a large, completely unobstructed area. It was necessary to work around several elements already present: the brick wall, the wooden door, the passageway, and the electrical connections.
The outdoor unit rests on a raised metal support, rather than directly on the concrete. This setup helps keep the lower part of the equipment away from water and debris on the ground and facilitates management of the space around the base.
In Saint-Basile-le-Grand, this height obviously does not exempt the owner from keeping the heat pump clear during the winter. A significant accumulation of snow around a condenser can hinder air intake and discharge. We therefore always consider the outdoor installation as a whole: location, support, airflow, winter drainage, and accessibility.
An interesting detail: the wooden lattice in front of the discharge area
An openwork structure does not act like a completely closed wall, but it should never be used as an excuse to arbitrarily reduce the clearances specified by the manufacturer.
In this type of environment, we must in particular verify that the fan can discharge air without causing significant recirculation around the condenser. A high-efficiency unit can lose part of its advantage if hot air in summer, or discharged cold air in heating mode, continually returns toward its heat exchanger.
This is an example of a detail that is invisible in a quote but very important once the system is operating.
Lines grouped along the brick rather than a scattered network
The insulated lines running vertically along the wall are also visible in the photo. On a dual-zone heat pump, organizing the refrigerant lines and wiring requires more attention than on a single-zone system.
Each indoor unit must be correctly matched to its connections. Midea has also integrated a feature called SynchroConnect into its multi-zone platform, designed to verify the correspondence between the wiring and refrigerant lines and facilitate connection synchronization.
This technology is a useful aid for the installer, but it obviously does not replace methodical work. At AirGreen, we always strive to achieve a routing:
short where possible, protected, securely fastened, accessible, and visually consistent with the building.
On a brick facade or in an exterior passage visible to occupants every day, this finish makes a significant difference.
Why inverter technology is particularly useful with two zones
A residence almost never requires its maximum heating or cooling capacity continuously.
In the morning, one zone may require more heat. In the afternoon, a room with strong sun exposure may become the priority. At other times, only one of the two zones may actually need to operate.
The inverter technology of Midea's multi-zone system allows the output capacity to vary according to conditions. The manufacturer's documentation states that the compressor and fan motors adjust their operation to demand and that the system can operate at partial load when not all rooms need cooling or heating.
This is particularly relevant for a two-zone heat pump, because the building's behavior changes continuously. The goal is not simply to get a unit capable of producing a lot of BTUs; we also want it to efficiently handle periods when demand is low.
MIDEA28 does not automatically mean 28,000 BTU
This is an important distinction for homeowners comparing heat pumps online.
MIDEA28 is a product line, not a single capacity. The number of zones alone is also not enough to determine the required outdoor unit capacity.
In the Midea documentation provided, the Extreme Heat multi-zone family includes, among others, a 27,000 BTU/h MO4HX-H27B-2A outdoor unit. The reference ductless configuration is associated with AHRI 215471460.
For this version, Midea publishes the following specifications:
| Feature | MIDEA Extreme Heat MO4HX-H27B-2A |
|---|---|
| Nominal cooling capacity | 27,000 BTU/h |
| Nominal heating capacity | 27,000 BTU/h |
| Power supply | 208/230 V, 1 phase, 60 Hz |
| SEER2 | 23 |
| EER2 | 12,5 |
| HSPF, Region IV | 10,5 |
| Heating at 5 °F / -15 °C | 27,000 BTU/h |
| COP at 5 °F / -15 °C | 2,0 |
| Maximum outdoor airflow | 2 148 CFM |
| Published outdoor sound level | 61 dB(A) |
| Dimensions | 37 1/4 × 16 1/8 × 31 7/8 in |
These values are for the reference MO4HX-H27B-2A in the brochure, and are not a claim based solely on the label visible in the photo, which is not clear enough to confirm the complete model number of the installed condenser.
This clarification is important: at AirGreen, we prefer to clearly distinguish a documented specification of the product line from a characteristic that cannot be verified from the photo.
Midea's current catalog also indicates that the Extreme Heat multi-zone systems, including the MO4HX-H27B-2A, are designed for a heating range that can drop as low as -22 °F, or approximately -30 °C.
Why two zones should never be sized simply by adding the BTUs listed on the heads
This is one of the most common mistakes when comparing multi-zone systems.
Suppose there are two indoor units. Mechanically adding the rated values listed on each one and then choosing the condenser with the immediately higher figure is not a real sizing method.
Midea itself specifies that when the total capacity of the indoor units exceeds the rated capacity of the outdoor unit, the capacity actually available to each unit may be reduced, particularly in heating mode.
We must therefore take the building's actual conditions into account:
floor area, insulation, number of windows, their orientation, heat loss, ceiling height, floor, solar exposure, airflow between rooms, and design outdoor temperature.
That is why two neighboring homes in Saint-Basile-le-Grand may need very different configurations, even if they both have “two zones.”
A range capable of accommodating multiple indoor unit styles
Midea's flexibility is not limited to wall-mounted heads. The brochure includes several indoor unit formats, including wall-mounted units, consoles, cassettes, and ducted units. The system is designed for applications with or without ducts, and certain configurations can even combine both approaches.
For a classic two-zone residential installation on the South Shore, wall-mounted units are often the simplest solution, but they are not automatically the best choice for every room.
A room with limited wall space may sometimes be better suited to a console. A renovated area with a dropped ceiling may allow for a ducted solution. In a more architectural project, a cassette may be considered.
That is precisely why we begin by studying the home before finalizing the equipment combination.
What this MIDEA28 installation in Saint-Basile-le-Grand shows before choosing a dual-zone heat pump
The condenser must remain accessible after installation, not just on the day of the job
One of the good practices visible in this installation is leaving the side with the service panels accessible.
A heat pump is mechanical equipment that will one day need to be inspected, cleaned, or diagnosed. Placing a condenser in a space where no technician can reach the valves, connections, or electrical panel creates a problem that may not become obvious until several years later.
In the passage shown in the photo, every centimeter counts. We must therefore consider both occupant traffic and access for the future refrigeration technician.
The outdoor disconnect is an integral part of a clean job
On the brick wall, to the right of the outdoor unit, we can see the electrical disconnect box.
For a homeowner, it may seem secondary to the heat pump itself. For us, it is part of the system. Electrical connections must be safe, protected from the elements, and arranged so they remain accessible.
One of the differences between an installation that looks improvised and a professional HVAC installation is often found in these peripheral elements: cable fastening, piping finish, drainage, outdoor protection, and electrical disconnect organization.
The A2L pictogram visible on the unit also changes certain work practices
The technical plate visible in the photo clearly displays an A2L marking with a flame pictogram.
A2L-class refrigerants require proper handling and installation procedures. For the customer, this does not mean that a heat pump suddenly becomes dangerous; it mainly means that the work must be performed by professionals who know the requirements applicable to next-generation equipment.
This is another example of why the installer’s choice matters just as much as the brand name on the condenser.
LogisVert rebate: look at the AHRI number, not just the word MIDEA28
For homeowners in Saint-Basile-le-Grand, Montreal, Laval, Longueuil, the North Shore, and the South Shore who wish to take advantage of financial assistance, it is important not to assume that a product-line name automatically guarantees a specific amount.
For residential installations meeting the current criteria, Hydro-Québec indicates that an ENERGY STAR heat pump may qualify for $50 per 1,000 BTU/h at -8 °C, while an ENERGY STAR – Cold Climate heat pump may be eligible for $120 per 1,000 BTU/h at -8 °C. Units installed since November 26, 2025, must be ENERGY STAR to be eligible.
The determining figure is therefore not simply the nominal capacity of 18,000, 24,000, or 27,000 BTUs displayed in a brochure. Hydro-Québec uses the recognized capacity at -8 °C of the eligible combination.
That is why we check the AHRI number, outdoor model, and combination of indoor units before announcing financial assistance to the customer.
This check is even more important with a multi-zone system, since the same outdoor unit can be used with different indoor combinations.
The mistakes we aim to avoid on a two-zone installation
On our heat pump projects in Montreal, Laval, Longueuil, the North Shore, and the South Shore, several potential problems come up regularly. A well-planned installation aims in particular to avoid:
- An oversized condenser solely because it serves two rooms.
- Two indoor units selected without calculating the actual needs of each zone.
- An outdoor air outlet that is too confined by a fence, wall, or storage area.
- Refrigerant lines left unsupported or routed in an unnecessarily complex manner.
- Service access sacrificed to save a few centimetres.
- An outdoor unit directly exposed to snow accumulation without a winter maintenance strategy.
- A rebate amount announced before the exact AHRI combination has been verified.
These points may seem secondary when comparing two prices. They become much more important when the heat pump operates daily for ten or fifteen heating and cooling seasons.
After commissioning: how to preserve the performance of both zones
A successful installation must also remain efficient.
The indoor unit filters must be cleaned regularly. The condenser must remain clear of leaves, vegetation, snow, and stored objects. The drains must properly discharge condensate, and any unusual change in noise, airflow, or capacity should be checked.
In this case, the outdoor space is also used as a passageway. It will therefore be particularly important not to gradually turn the area around the condenser into a storage space.
The best heat pump cannot operate properly if its air exchanger ends up surrounded by boxes, furniture, or compacted snow.
An AirGreen project that shows why details matter
This MIDEA MIDEA28 dual-zone heat pump installation in Saint-Basile-le-Grand is not remarkable because it includes an exceptional number of units. It is interesting precisely for the opposite reason: a lot had to be accomplished in a relatively restricted outdoor space.
A single outdoor unit had to serve two zones, remain accessible in an existing passageway, integrate with a brick wall, and coexist with an existing wooden structure.
This type of project accurately represents our work at AirGreen. We do not simply look for a place where the heat pump “fits.” We consider how it will breathe, how the lines will be routed, how the electrical system will be organized, how it will be maintained, and how the installation will remain practical for the occupants.
Whether the project is located in Saint-Basile-le-Grand, Boucherville, Longueuil, Montreal, Laval, on the South Shore or the North Shore, our approach remains the same: choose the right HVAC combination for the building, then carry out an installation that allows this machine to truly deliver the performance for which it was designed.
For a homeowner considering a dual-zone heat pump, the best starting point is therefore not simply to ask “how many BTUs?” It is necessary to determine which two zones need to be treated, their respective needs, the possible locations of the indoor units, the route of the lines, the available outdoor space, and the combination eligible for financial assistance programs.
It is this complete analysis that transforms equipment that performs well on paper into a comfortable, durable system in a real Quebec home.
The job tools
Two quick checks with real numbers: what heat costs, and what your current heaters add up to in BTU/h.
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.
How the job unfolds
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 we check on a job like this one
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.
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.
Good habits, once the unit is in place
Six simple habits that keep the unit going. Your list stays on this device.
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.
The right pages, at the right time
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.
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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).