Installation of a MIDEA 28 dual-zone heat pump in Mont-Saint-Grégoire
In Mont-Saint-Grégoire, AirGreen installs a MIDEA 28 dual-zone heat pump with protected lines and a neat finish, providing independent comfort in two zones and an HVAC installation suited to Quebec’s climate.
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A dual-zone installation designed to cool and heat two spaces with a single outdoor unit
At Mont-Saint-Grégoire, we completed an installation that clearly illustrates the value of a multi-zone heat pump when a homeowner wants better comfort control in different parts of the house without adding multiple outdoor units. For this project, our AirGreen team installed a MIDEA 28 dual-zone heat pump, with a single outdoor unit serving two indoor units.
The installation photo shows an element that we consider just as important as the equipment selection itself: the quality of the system’s integration into the building. The MIDEA outdoor unit was installed against a brick façade, while the refrigerant lines, wiring, and necessary connections are grouped inside a brown vertical line-set cover, chosen to better blend with the color of the masonry.
This type of detail makes a considerable difference in a home. A high-performance heat pump must be properly sized and installed, but it must also leave a clean, durable, and logical exterior finish.
For this installation in Mont-Saint-Grégoire, choosing a MIDEA 28 dual-zone system provides the main advantage of a multi-zone system: a single outdoor heat pump can power several indoor zones with separate controls. MIDEA describes this principle precisely in its documentation: a multi-zone installation connects one outdoor unit to several indoor units that can be controlled individually according to the desired temperature in each room.
Why install a dual-zone heat pump instead of two independent systems?
In many homes in Mont-Saint-Grégoire, Longueuil, Montréal, Laval, on the South Shore and on the North Shore, heating and cooling needs are not uniform from one room to another.
A room located upstairs can overheat in summer while a living space on the ground floor remains relatively comfortable. Conversely, some peripheral rooms can be much more difficult to keep at a pleasant temperature during cold periods.
A dual-zone heat pump therefore makes it possible to use two indoor units connected to the same outdoor unit.
The main advantages are as follows:
- two distinct comfort zones;
- a single outdoor unit on the property;
- the ability to adjust each indoor unit individually;
- capacity modulation through inverter technology;
- reduced number of visible pieces of equipment around the house;
- the ability to heat or cool primarily the spaces that are actually being used.
MIDEA documentation also emphasizes that the indoor units can have different settings depending on how the rooms are used. The system can therefore operate at partial load when all zones do not simultaneously require their full capacity, which is one of the fundamental advantages of a multi-zone inverter system.
MIDEA 28’s inverter operation
An inverter heat pump does not simply operate according to an on-off logic at full power.
The compressor can instead modulate its operation according to the building’s actual needs. As the indoor temperature approaches the setpoint, the system can reduce its capacity rather than shutting down completely and restarting a few minutes later.
In a dual-zone installation, this modulation becomes even more important.
For example, if both indoor units require significant heating after a temperature drop, the outdoor unit can increase its output. Once one zone reaches its setpoint while the other still requires heating, the heat pump adjusts its operation to the new conditions.
MIDEA states that its multi-zone system uses inverter technology to adjust capacity by controlling, among other things, the compressor and fan motors. When only part of the house requires heating or cooling, partial-load operation can reduce consumption compared with a constant demand at full capacity.
A single outdoor unit to simplify the layout
In the photo of this installation in Mont-Saint-Grégoire, the outdoor unit is located directly against the residence’s brick wall.
This configuration illustrates another practical advantage of the MIDEA multi-zone system: it avoids installing two separate condensers for two zones.
This point can be particularly important for:
- houses with a narrow side yard;
- properties where outdoor space is limited;
- buildings with multiple balconies or terraces;
- façades where homeowners want to limit the number of visible units;
- certain properties in Montreal or Longueuil where every square foot of outdoor space matters.
The manufacturer’s documentation also identifies space savings and a reduced number of outdoor units as advantages of the multi-zone design.
A particularly important exterior finish on a brick façade
The feature that immediately draws our attention on this installation is the brown vertical line-set cover.
Technically, we could have left part of the lines more exposed. However, that is not our preferred way to carry out a residential installation when the architecture allows for a more polished finish.
The line-set cover serves several purposes.
It protects and conceals, among other things:
- the insulated refrigerant lines;
- the communication wiring;
- certain electrical conductors, depending on the configuration;
- condensate drainage when it follows this route;
- the connection components that must be routed between the units.
In this project, the brown colour works particularly well with the red brick and the home’s exterior elements. Although the line-set cover remains visible, it looks more like a vertical architectural element than an improvised set of mechanical lines.
For our wall-mounted heat pump installations on the South Shore, we pay close attention to this aspect, particularly when a line must run several metres along a highly visible façade.
A line route that must be planned before the first hole is drilled
A dual-zone installation requires more planning than a single-zone installation.
Before drilling through the masonry, we must establish the complete route of the lines between:
- the two indoor units;
- their refrigerant outlets;
- their drains;
- the exterior passage;
- the line-set manifold;
- the connections to the MIDEA outdoor unit.
This step is important because a decision made too quickly at the outset can leave visible consequences throughout the heat pump’s entire service life.
A poor routing choice can lead to:
- too many line-set covers;
- several unnecessary changes in direction;
- a line visible in front of a window;
- lines that cross a terrace;
- an unsuitable slope for a gravity drain;
- connections that are difficult to maintain;
- an unattractive exterior finish.
On this installation in Mont-Saint-Grégoire, the lines arrive behind and near the outdoor unit, then are neatly grouped in the vertical line-set cover. The result remains compact despite the presence of two indoor circuits.
MIDEA’s SynchroConnect technology for multi-zone systems
The MIDEA technical brochure also presents an interesting feature for installers: SynchroConnect.
In a multi-zone system, several pairs of refrigerant lines and several electrical connections link the indoor units to the outdoor unit. This normally requires very close attention to match each refrigerant circuit with the corresponding indoor unit.
According to MIDEA, SynchroConnect allows the system to diagnose the status of the connections and can synchronize the refrigerant lines with the electrical connections in certain situations, simplifying the commissioning of the multi-zone system.
This obviously does not replace professional installation or the required technical checks, but it is an interesting example of how modern multi-zone systems are designed to simplify troubleshooting and commissioning.
A MIDEA platform designed for multiple types of indoor units
Although this installation is used as a dual-zone system, one of the strengths of the MIDEA multi-zone platform is its flexibility.
The brochure presents several categories of compatible indoor units, including:
- wall-mounted units;
- console units;
- cassette units;
- ducted units;
- ceiling-floor units;
- air-handling units.
MIDEA states that this platform can combine ducted or ductless applications, depending on the configuration selected.
This versatility becomes particularly appealing when a homeowner wants to condition two completely different spaces.
For example, we may encounter a home where a wall-mounted unit is perfectly suited to the ground floor, while a ducted solution makes more sense for a few bedrooms. The final choice always depends on the property’s configuration, heating and cooling needs, and the combinations officially approved by the manufacturer.
What you need to understand about sizing a multi-zone system
One of the most common mistakes when comparing multi-zone heat pumps is simply adding up the BTUs listed on the indoor units.
A multi-zone system should not be selected this way.
MIDEA publishes precise tables indicating which combinations of indoor units are permitted for each outdoor unit. The brochure also highlights an essential point: when the total capacity of the indoor units exceeds the rated capacity of the outdoor unit, the capacity actually available to each unit may decrease, particularly in heating mode.
This is particularly relevant in Quebec.
On a moderately warm summer day, the two zones may never require their full capacity at the same time. During a very cold period, however, both rooms may require a great deal of heating at the same time.
We must therefore take into account:
- the area of each zone;
- insulation;
- solar exposure;
- the number and quality of the windows;
- ceiling height;
- the floor where the room is located;
- air infiltration;
- the outdoor unit’s actual capacity at low temperatures;
- the combination of indoor units approved by MIDEA.
An oversized system is not automatically better. A properly selected heat pump generally provides more stable operation and better comfort management.
What this MIDEA 28 installation in Mont-Saint-Grégoire shows about the AirGreen approach
The installation is never limited to placing the unit against a wall
For us, a successful HVAC installation depends on several decisions that are not necessarily visible once the work is complete.
We must determine the best location for the outdoor unit while considering:
- access for servicing;
- the required clearance;
- air circulation;
- snow;
- defrosting in winter;
- the route of the lines;
- the proximity of the windows;
- the building’s structure;
- the installation’s final appearance.
The photo from Mont-Saint-Grégoire illustrates a project where the integration of the refrigerant lines was handled carefully. The outdoor conduit runs vertically up the brick before reaching the level required for the indoor units.
Why the outdoor unit’s position matters in winter
In our climate, we never choose a location based solely on summer conditions.
In heating mode, an outdoor heat pump must handle much more demanding conditions: below-freezing temperatures, snow, ice, and defrost cycles.
The unit must therefore be positioned with enough space for air to circulate properly around the heat exchanger.
It is also important to prevent a drainage problem or ice buildup beneath the unit from eventually affecting its operation.
For a heat pump installation in Mont-Saint-Grégoire, as with our projects in Montréal, Laval, Longueuil, on the North Shore or the South Shore, these winter constraints must be considered from the very beginning of the project.
Commissioning as important as the mechanical installation
A multi-zone heat pump may appear to operate normally for a few minutes after startup while having a problem that will only become apparent later.
That is why commissioning must include several checks.
We pay particular attention to:
- refrigerant connections;
- leak tightness;
- system evacuation before releasing the refrigerant;
- communication connections;
- the operation of each indoor unit;
- heating and cooling output;
- condensate drainage;
- controls;
- different fan speeds;
- simultaneous zone operation;
With a dual-zone system, we must pay particular attention to ensuring that each indoor unit communicates properly with the outdoor unit.
Mistakes we strive to avoid with a dual-zone heat pump
After numerous multi-zone system installations in Greater Montreal, certain mistakes keep recurring when we inspect existing installations.
Choosing BTUs based solely on floor area
Two rooms of the same size do not necessarily have the same heat losses and gains.
A south-facing room with large windows may require a different approach from a smaller bedroom on the north side.
Installing the indoor unit based solely on appearance
The location must also allow for effective air distribution.
An indoor unit placed in a corner because it is less visible may have considerable difficulty treating the entire room.
Neglecting the drain route
Condensate drainage must be planned before installation begins. An insufficient slope can cause drainage problems.
Ignoring the aesthetics of outdoor lines
A poorly planned piping route can become the most visible detail of the entire installation.
The Mont-Saint-Grégoire project shows why we plan the line-set cover and its alignment from the outset.
Unnecessarily oversizing
More BTUs do not necessarily mean greater comfort. Sizing must be based on the building’s needs as well as the combinations permitted by the manufacturer.
Energy efficiency, AHRI, and eligibility for rebates
The MIDEA multi-zone lineup presented in the technical documentation includes several Extreme Heat models with distinct AHRI references depending on the outdoor capacity and indoor unit combination.
For example, the brochure indicates the following for certain non-ducted Extreme Heat configurations:
- 18,000 BTU: AHRI 215471457;
- 27,000 BTU: AHRI 215471460;
- 36,000 BTU: AHRI 215471463;
- 48,000 BTU: AHRI 215471466;
- 60,000 BTU: AHRI 215471469.
The documentation also indicates SEER2 ratings of up to 25 on certain Extreme Heat configurations, with values that vary according to the capacity and certified combination.
However, it is important not to take an AHRI reference from a different configuration and apply it automatically to an installation.
Eligibility for financial assistance or a program such as LogisVert must always be verified according to the exact combination installed: outdoor unit, indoor units, capacity, certification, and the program criteria in effect when the application is submitted.
At AirGreen, we therefore verify the system actually being proposed rather than relying solely on the commercial name MIDEA 28.
A particularly attractive solution for homes with two zones that are difficult to balance
A dual-zone heat pump is not necessarily the best solution for every home, but it becomes especially attractive when there are two spaces that need to be controlled independently.
We particularly consider it for:
- a ground floor and an upper floor;
- a living room and a primary bedroom;
- a home with an addition;
- a basement and a living area;
- two separate apartments or areas when the configuration allows;
- a room located far from the main heating system;
- spaces with different occupancy schedules.
The value therefore lies not only in the number of units. It lies primarily in the ability to create comfort zones adapted to the home’s actual use.
AirGreen for MIDEA heat pump installation in Mont-Saint-Grégoire and Greater Montreal
This MIDEA 28 dual-zone heat pump installation in Mont-Saint-Grégoire reflects our way of working: selecting a solution suited to the building, carefully planning the line routing, protecting the connections, and achieving a clean finish.
We install and maintain heating, air conditioning, and heat pump systems in Montreal, Laval, Longueuil, the South Shore, and the North Shore, as well as in several surrounding municipalities.
For a multi-zone project, our goal is not simply to offer the largest possible equipment. Instead, we look for the combination that provides the right balance between capacity, modulation, comfort, energy efficiency, unit placement, and installation quality.
A well-chosen MIDEA multi-zone heat pump can provide an excellent solution when a home requires several temperatures or multiple treatment zones, but everything depends on the project’s design.
It is precisely at this stage that the installer’s experience becomes decisive.
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).