Installation of a MIDEA 28 dual-zone heat pump in Saint-Antoine-sur-Richelieu, in Montérégie

A MIDEA 28 installation designed around the building, not the other way around

At Saint-Antoine-sur-Richelieu, this installation of a MIDEA 28 dual-zone heat pump clearly illustrates a reality we regularly encounter at AirGreen: the quality of an HVAC project does not depend solely on the equipment selected. The positioning of the outdoor unit, the routing of the refrigerant lines, access for maintenance, protection against snow, and how comfort is distributed among the different rooms all matter just as much.

On this masonry property, the MIDEA outdoor unit was installed high up on metal wall brackets, rather than directly at ground level. The white line-hide covers run horizontally along the façade on both sides of the unit, while the electrical connection leads to an outdoor disconnect installed nearby. The result is compact, organized, and particularly well suited to a location where the ground area must remain clear.

For this residence, choosing a multi-zone heat pump configured into two zones makes it possible to use a single outdoor unit to supply two separate spaces. This is precisely the principle behind the MIDEA multi-zone system: a single outdoor unit can be connected to several indoor units, with each indoor unit adjustable individually according to the desired temperature in the room concerned.

Why a dual-zone heat pump was particularly relevant here

A dual-zone installation is not simply a heat pump with a second wall-mounted unit added. To achieve a comfortable and efficient result, we must consider the home as two different thermal spaces.

An upstairs bedroom does not experience the same solar gains as a living room. A room facing due south does not respond like a shaded room. An open-concept space with a kitchen can receive much more internal heat than a bedroom used primarily at night.

With a MIDEA 28 dual-zone, we can distribute cooling and heating where they are actually needed, rather than trying to circulate air from a single wall-mounted unit through several distant rooms.

MIDEA documentation specifically highlights this advantage: each zone can have its own setting, allowing you to heat or cool primarily the rooms being used rather than the entire residence uniformly.

This becomes particularly interesting for multi-level homes and residences where a single central wall-mounted unit would have difficulty maintaining an even temperature.

An outdoor unit installed at height: a visible detail that is very important in Quebec

The most striking element in the photo of our installation in Saint-Antoine-sur-Richelieu is the height at which we positioned the condenser.

This choice addresses several practical considerations.

In Quebec, a heat pump used for heating must continue to breathe properly during the winter. A unit placed too close to the ground can become surrounded by snow after a storm or after a snowblower passes. Ice can also accumulate around the unit during defrost cycles.

By mounting the outdoor unit on sturdy metal supports, we create substantial clearance beneath the unit. This facilitates the drainage of defrost water and reduces the risk of snow obstructing the lower part of the heat pump.

In this particular configuration, wall mounting also offers another advantage: it completely frees up the floor space.

This is a point that is often overlooked when preparing a quote. A unit installed in front of a passageway, a small yard, a storage area, or a secondary entrance can quickly become an obstruction. We therefore assess how the property is actually used before determining the final location.

Wall supports must be designed as an integral part of the installation

Suspending a heat pump of this size on a facade is not simply a matter of attaching two brackets.

We must take into account the building’s structure, the unit’s weight, the vibrations produced by the compressor and fan, as well as the clearances needed to carry out any maintenance or repairs.

In the photographed installation, two large vertical metal supports hold the outdoor unit above the lower level of the facade. This type of mounting provides an open base beneath the unit and keeps the main service panels accessible.

A poorly executed wall-mounted installation can transmit more vibration to the structure. This is why the choice of support, type of anchoring and positioning are just as important as the choice of the heat pump itself.

A clean pipe run on a brick façade

A multi-zone heat pump installation also means several connections between the outdoor unit and the indoor units.

The refrigerant lines, communication wiring and drains associated with the indoor units all need to be routed. When these elements run across a visible façade, the final appearance becomes a significant consideration.

For this installation in Saint-Antoine-sur-Richelieu, we grouped the lines in white line covers that follow the building’s architectural lines. They are installed horizontally beneath the windows and on either side of the outdoor unit.

The goal is not to make the lines disappear completely - which is rarely possible with an existing wall-mounted installation - but to give them a logical, straight and discreet route.

This is precisely the kind of detail that can make two installations using exactly the same heat pump look completely different.

A clearly accessible outdoor electrical connection

To the right of the MIDEA unit, the outdoor electrical disconnect can also be seen.

Its role is important for safety and maintenance. A technician must be able to electrically isolate the equipment before carrying out certain work on the outdoor unit.

We therefore look for a location that remains accessible without creating an unnecessarily complex cable route.

In this installation, the connection remains in the immediate vicinity of the outdoor unit, creating a compact technical assembly while maintaining convenient access.

Inverter technology: important in a dual-zone installation

A dual-zone system does not operate constantly at maximum capacity.

When both spaces require significant heating or cooling, the system must provide more capacity. When only one zone requires a few degrees of adjustment, the needs are different.

This is precisely where inverter technology becomes interesting.

MIDEA documentation explains that the system adjusts its capacity according to temperature changes by controlling compressor and fan motor operation. When not all rooms need air conditioning or conditions become less demanding, the equipment can operate at partial load and reduce its energy consumption.

In a real home, this means that a properly sized multi-zone system does not need to operate continuously according to a full-power on-off cycle.

It modulates.

And this modulation is particularly useful when one zone reaches its setpoint before the other.

MIDEA 28: Be careful not to confuse the series name with the actual capacity in BTUs

When a homeowner compares MIDEA heat pumps, a common mistake is to automatically infer the equipment’s capacity from the product name.

For a multi-zone installation, we always prefer to work with the exact outdoor unit number, the combination of indoor units, and the corresponding AHRI reference.

The technical documentation provided by MIDEA shows several Extreme Heat condensers belonging to the same multi-zone family. For example, it lists the MO3HX-H18B-2A with AHRI reference 215471457, as well as the MO4HX-H27B-2A with AHRI reference 215471460.

For the first pairing listed by MIDEA, the documentation states a rated cooling/heating capacity of 19,000 / 20,000 BTU/h, a SEER2 of 25, an EER2 of 15, and an HSPF4 of 10.4. The reference 27,000 BTU model is listed at 27,000 / 27,000 BTU/h, with a SEER2 of 23, an EER2 of 12.5, and an HSPF4 of 10.5.

These figures also demonstrate why we never determine capacity solely from a photograph. At the site shown here, the detailed rating label on the condenser is not legible enough in the photo to confirm its submodel and exact AHRI match without ambiguity. We therefore prefer not to assign an unverified BTU capacity artificially.

This is the same method we use when preparing a quote: sizing must be based on the building and the actual models, not a visual estimate.

Sound level and placement near the house

The sound level of an outdoor unit matters greatly when the equipment is located near windows.

In the documentation provided, the reference Extreme Heat 18K unit is listed at 62 dB(A) and the 27K at 61 dB(A). In this table, both use a chassis approximately 37 1/4 in. wide, 16 1/8 in. deep, and 31 7/8 in. high.

This also explains why the choice of location deserves careful consideration.

We specifically examine bedroom windows, terraces, property lines, traffic areas, and maintenance access. The shortest piping route is not necessarily the best solution for the owner.

An interesting feature for installers: SynchroConnect

The multi-zone lineup described by MIDEA also incorporates an interesting technology called SynchroConnect.

In a multi-zone system, each indoor unit has associated refrigerant and electrical connections. The more zones there are, the more important it becomes to accurately identify the connections during commissioning.

According to MIDEA, SynchroConnect can diagnose the status of the connections after the wires and lines have been connected. The system can also synchronize the correspondence between certain refrigerant lines and the wiring when the connections have been crossed between the ports.

This obviously does not replace a methodical installation. For us, it is an additional validation tool during commissioning.

A multi-zone heat pump remains a complex refrigeration system. The connection, evacuation, leak testing, and startup steps must be carried out correctly before the installation is handed over to the owner.

Two zones do not mean two completely independent systems

There is also an important distinction to understand before purchasing a dual-zone heat pump.

Each indoor unit can have its own temperature setpoint, but the indoor units always share the same outdoor refrigeration system.

This means that the home’s needs must be considered as a whole.

If a bedroom requires very little capacity and a large open-concept area requires much more heating, we do not choose two identical indoor units simply to simplify the quote. Each zone must be sized according to its heating load.

MIDEA’s documentation also contains numerous tables of indoor unit combinations. It specifies that when the total indoor load exceeds the outdoor unit’s rated capacity, the capacity actually available to each unit may be reduced, particularly in heating mode.

This is an extremely important technical point for Quebec's climate.

Adding more nominal BTUs indoors does not magically create more outdoor capacity.

ENERGY STAR eligibility and subsidies: verify the exact match

Homeowners in Montreal, Laval, Longueuil, the North Shore and the South Shore regularly ask us whether a multi-zone heat pump qualifies for financial assistance.

The correct answer must always be based on the actual installed combination.

The MIDEA brochure presents specific tables of indoor unit combinations under the ENERGY STAR heading and associates the various outdoor units with precise AHRI references.

For a subsidy application, the name “MIDEA 28” or the mere fact that it is a low-temperature heat pump is therefore not enough. In particular, you need to verify:

• the exact outdoor condenser number;
• the models of each of the two indoor units;
• the selected capacity combination;
• the AHRI reference corresponding to this combination;
• the subsidy program criteria applicable at the time of installation.

This is particularly important for Quebec assistance programs, whose criteria and amounts can change. At AirGreen, we prefer to confirm eligibility based on official documentation rather than announce a subsidy simply based on a product line name.

The mistakes this installation helps avoid

This project in Saint-Antoine-sur-Richelieu highlights several best practices that also apply to a heat pump installation in Montreal, Laval, Longueuil, on the North Shore or the South Shore.

The first is not to automatically place the outdoor unit on the ground simply because it is the fastest solution.

The second is to plan the line-set route before drilling through the facade.

The third is to size the two zones separately.

The fourth is to maintain reasonable access to the condenser and disconnect switch for future HVAC maintenance.

Finally, the exact equipment match must always be verified when energy efficiency or a subsidy influences the purchase decision.

A good installation therefore begins several hours before the heat pump is turned on.

It starts with choosing the location.

What this MIDEA 28 installation in Saint-Antoine-sur-Richelieu shows about our approach at AirGreen

At AirGreen, we do not consider a dual-zone heat pump to be simply an assembly consisting of a condenser and two indoor units.

We examine the building, room layout, heating needs, air circulation, outdoor constraints, masonry, piping distances, and future maintenance requirements.

At this Saint-Antoine-sur-Richelieu residence, the elevated installation of the outdoor unit is particularly representative of this approach. We avoided unnecessarily occupying ground space while maintaining substantial clearance beneath the heat pump. The line covers follow the façade neatly, and the electrical connection remains accessible.

For the homeowner, the advantage of a dual-zone system is tangible: two spaces can be controlled separately with a single outdoor unit. For us, the challenge is to ensure that this flexibility remains truly effective when temperatures drop.

That is why the choice of indoor capacities, matching them with the outdoor unit, commissioning, and installation quality are just as important as the brand displayed on the condenser.

The MIDEA multi-zone line also offers considerable flexibility. The manufacturer's documentation presents wall-mounted units, consoles, cassettes, and ducted units, with the possibility of combining ducted and ductless solutions in certain configurations.

Even when we install only two zones, this architecture therefore makes it possible to adapt the solution much more precisely to the building.

For a homeowner currently comparing a MIDEA heat pump, a dual-zone heat pump, a multi-zone system, or another heating and cooling solution, our recommendation remains the same: start with the home, and only then turn to the catalogue.

At AirGreen, we carry out HVAC installations in Montreal, Laval, Longueuil, on the South Shore, the North Shore, and in several municipalities across the Greater Montreal area, with particular attention to sizing, outdoor positioning, line-set finishing, and actual heating performance.

This MIDEA 28 installation in Saint-Antoine-sur-Richelieu is a good example: a well-integrated dual-zone system installed on an existing façade in a way that preserves floor space while providing a heating and cooling solution suited to the property's actual needs.