Installation of a MIDEA EVOX G3 electric furnace in Blainville, on Montreal’s North Shore

In Blainville, a side-by-side MIDEA EVOX G3 installation that truly takes advantage of the system's modularity

This MIDEA EVOX G3 electric furnace installation in Blainville is particularly interesting because it does not resemble the classic image of a central unit made up of several sections stacked vertically. In this mechanical room on the North Shore, the available space and the ductwork layout led to a much more unusual configuration: the main EVOX G3 modules are arranged side by side, then connected to the ventilation network using custom-fitted sheet-metal transitions.

This is precisely the type of situation in which a modular architecture becomes a real installation advantage.

In the final site photo, the constraints are immediately apparent. The MIDEA module on the left occupies practically all the available height beneath the ductwork. On the right, the second section houses the refrigerant connections, condensate drainage, and a substantial metal transition rising toward the air distribution network. Between the two units, the wiring and connections were grouped in a very tight space.

It was therefore not enough to choose an efficient unit. It was necessary to determine how to make this unit work with the building's actual architecture.

Two sections side by side rather than one long vertical furnace

This is the detail that makes this Blainville project different from many other central installations we carry out in Montreal, Laval, Longueuil, on the North Shore and the South Shore.

The MIDEA EVOX G3 uses a modular design called Block N Lock. The manufacturer's documentation shows that the sections can be reconfigured to provide several orientations: upflow, downflow, right horizontal, left horizontal, as well as low-height variations. MIDEA specifically promotes this architecture for basements, attics, and other spaces where a conventional unit becomes difficult to transport or position.

In this installation, the visible layout is precisely similar to a low-profile application, where the ability to distribute the components is used rather than imposing a single large vertical column.

This flexibility can avoid major building modifications.

With a traditional packaged unit, it would sometimes have been necessary to:

• rebuild more ductwork;
• relocate certain connections;
• lose usable space;
• create more restrictive transitions;
• or select a less suitable unit simply because it physically fit in the room.

Here, we instead used the equipment configuration to adapt to the building.

The left and right sides do not serve the same purpose

In the photograph, the two gray cabinets might give the impression that they are two different furnaces. In reality, this configuration illustrates the modular nature of the central system.

The right-hand section is particularly revealing: here we can see the large black-insulated refrigerant pipe, the smaller copper pipe, as well as the condensate outlet connected to a white pipe.

These elements identify the section containing the coil associated with the refrigeration circuit.

The left side houses another functional section of the unit. On its front, we can see the control display, service panels, technical plate, and the marking A2L associated with the next-generation refrigerant used by the product line.

This physical separation is one of the features that allows the EVOX G3 to be installed in locations where a conventional central unit could be much more difficult to install.

A sheet-metal transition fabricated to connect neatly to the existing ductwork

Above the right-hand module, we can see a large rectangular sheet-metal transition extending up to the ventilation ductwork.

This type of component deserves more attention than one might think.

In a central HVAC installation, a transition is not only used to connect two openings of different sizes. Its shape also affects:

• the air velocity;
• turbulence;
• static pressure;
• sound level;
• airflow distribution;
• the work required of the fan.

A transition that is too abrupt or unnecessarily narrow can become a permanent restriction in the system.

In Blainville, sheet metal work is therefore an integral part of the installation of the MIDEA electric furnace, just like the refrigerant or electrical connections.

Another visible detail: the flexible connection on the ducts

In the upper-left part of the photo, we can also see a flexible connection between two metal sections of the ductwork.

This type of connection is commonly used in central systems to reduce the direct transmission of certain vibrations between the equipment and the ducts.

It is a relatively subtle detail in a construction-site photo, but it clearly illustrates a reality of our trade: comfort is not measured solely in degrees Celsius.

A good system must also limit:

• vibrations;
• whistling;
• sheet metal resonances;
• excessive airflow variations;
• operating noises transmitted throughout the house.

An “electric furnace” that does much more than produce resistance heat

In Quebec, we commonly use the expression electric furnace to refer to the central unit that heats and circulates air through the ducts.

The MIDEA EVOX G3 is more precisely a central air handler that can be paired with a heat pump and auxiliary electric heating.

This means that the same ductwork can be used to:

• heat the home with the central heat pump;
• provide auxiliary electric heating when necessary;
• cool the home;
• filter the air;
• distribute airflow among the different rooms.

MIDEA offers configurable auxiliary heating kits with multiple stages and options of up to 25 kW. The documentation specifically presents 10, 15, and 25 kW configurations, along with activation adapted to temperature variations.

However, the capacity actually installed in this Blainville project cannot be reliably determined from the photograph. We therefore prefer not to arbitrarily state a number of kilowatts that has not been confirmed by the installation’s complete nameplate.

Why auxiliary electric heating must be sized rather than simply maximized

Installing a larger electric heating element is not automatically an advantage.

Proper sizing depends in particular on:

1. the building’s heat loss;
2. the heat pump’s low-temperature capacity;
3. electrical panel capacity;
4. available wiring;
5. airflow;
6. of the control strategy used.

An oversized electric heating element can place a significant load on the electrical grid without necessarily improving the system’s day-to-day operation.

In a central heat pump installation in Blainville, we instead aim to make the heat pump the primary heating source whenever conditions permit and to integrate electric backup heat in a coherent manner.

A central range developed for winter temperatures

Low-temperature performance is obviously an important criterion for a home located in Blainville, where winter temperatures can remain well below freezing for long periods.

According to MIDEA documentation, the EVOX G3 range is designed to continue operating down to -30°C. For certain configurations and test conditions, the manufacturer also indicates up to 100% heating capacity at -25°C, with a COP of approximately 1.9.

The range presented by MIDEA extends from approximately 18,000 to 54,000 BTU/h, with efficiencies reaching:

• 19 SEER2;
• 12.5 EER2;
• 10.8 HSPF2;
• a COP of up to 2.14 to 5°F, or approximately -15°C.

These are the maximum values for the EVOX G3 family and not necessarily those of the specific unit shown in the photograph.

The range’s technical sheet includes several combinations of 18,000, 24,000, 30,000, 36,000, 48,000, and 54,000 BTU/h, with different performance levels depending on the indoor-outdoor combination.

Why we do not make up the BTU count based on the cabinet size

A larger cabinet does not necessarily mean that we can determine its capacity simply by looking at a photo.

To determine the exact capacity of this installation, we would need to confirm the the complete model number of the indoor unit and that of the outdoor unit.

This precision is important for a homeowner comparing several quotes.

The terms “2 tons,” “3 tons,” or “36,000 BTU” are not enough to properly compare two systems. We also need to look at:

• actual heating capacity at low temperatures;
• SEER2;
• HSPF2;
• COP;
• the certified combination;
• the required airflow;
• the building’s characteristics.

Airflow becomes even more important with an unusual configuration

The side-by-side arrangement visible in this installation naturally draws attention, but what interests us most after the connection is the air’s behavior.

The EVOX G3 incorporates Computational Constant Airflow 2.0. According to MIDEA documentation, this technology allows the system to adjust the fan’s speed and power to better maintain the requested airflow when network conditions change. The manufacturer illustrates situations of up to 1.2 in. of water column static pressure.

MIDEA also provides up to 60 airflow adjustment levels, accessible in the system’s technical settings.

For us, this flexibility is particularly useful when replacing equipment while using an existing duct network.

However, this does not mean that a sophisticated fan can correct every ductwork error.

What we still need to check on the ventilation network

Even with constant-airflow technology, we always check:

• return size;
• supply sections;
• transitions;
• filters;
• elbows;
• grilles;
• restrictions;
• total static pressure.

In this installation in Blainville, the room geometry is unusual. The quality of the transitions between the modules and the ducts therefore becomes just as important as the equipment’s rated performance.

A central system must be considered as one continuous whole: return air, filtration, fan, coil, auxiliary heating, plenum, and distribution ducts.

The white drain visible in the photo is not just a simple accessory

At the lower right of the module containing the refrigerant connections, we can see a white pipe connected to the condensate drain.

When the heat pump operates in cooling mode, moisture in the air condenses on the indoor coil. This water must be collected and properly drained.

The drainage must therefore be designed to prevent, in particular:

• backups;
• leaks in the mechanical room;
• water accumulating in the pan;
• odors;
• moisture problems around the unit.

This is a less spectacular part of an HVAC installation, but improper condensate drainage can cause damage far more costly than a properly made connection from the outset.

R-454B and A2L marking: an important change for recent installations

The pictogram A2L is clearly visible on the unit on the left.

The EVOX central product line uses R-454B refrigerant. MIDEA indicates a global warming potential of 466 for this refrigerant.

This new generation of refrigerant also brings new installation and service requirements.

At AirGreen, this means that work methods, equipment used, and commissioning practices must be adapted to A2L systems.

For the homeowner, it is therefore particularly important to entrust the installation to a company that genuinely works with this generation of equipment rather than automatically applying practices used with older systems.

Filtration that must be selected according to the available pressure

MIDEA provides the EVOX G3 product line with filtration options of 1 in., 2 in., or 4 in., including certain MERV 13 configurations.

More filtration can be beneficial for reducing the amount of dust and particles circulating through the system, but the filter must always remain compatible with the required airflow.

Installing the most restrictive filter possible without measuring its effect on the system is not good practice.

We must consider the following simultaneously:

• the filter surface area;
• its MERV rating;
• the air velocity;
• the return capacity;
• the available static pressure.

Conventional thermostat or MIDEA communication

The EVOX G3 can also be integrated into several control architectures.

MIDEA indicates compatibility with its communication system as well as with certain installations using a thermostat 24 V. The documentation also describes communication that can reduce the need to run new control wires in certain renovations.

This is particularly useful in an existing home, where running a new cable may sometimes require opening finished walls or ceilings.

So the best solution is not always the thermostat offering the greatest number of features. It is the one that matches the installed system, the available wiring, and the homeowner’s habits.

And what about rebates for this MIDEA EVOX G3?

MIDEA’s documentation presents the EVOX G3 central product line as meeting high efficiency levels and mentions the specifications ENERGY STAR Most Efficient.

In Quebec, however, this does not automatically mean that a specific installation will receive financial assistance.

For an application Hydro-Québec’s LogisVert, we must verify the exact combination of the outdoor and indoor units, as well as its listing on the applicable lists at the time of installation.

The name “MIDEA EVOX G3” alone therefore cannot guarantee:

• eligibility;
• the amount;
• the capacity used to calculate the rebate.

This is a check we perform using the system’s exact references rather than its commercial name.

Mistakes to avoid when a mechanical room requires a special configuration

This Blainville installation highlights several mistakes that we avoid when modernizing a central system:

• assume that a new furnace must necessarily replicate the shape of the old one;
• stack components when the available height does not allow for it;
• create transitions that are too small solely to make installation easier;
• forget access to the panels;
• excessively bend the refrigeration lines;
• leave condensate without suitable drainage;
• choose capacity based solely on floor area;
• ignore the system’s static pressure;
• install auxiliary heating that is too powerful without checking the electrical supply;
• promise a rebate before confirming the model numbers.

The modularity of the MIDEA EVOX G3 gives us more possibilities, but it also requires us to think about the installation as a whole.

This Blainville project sums up our approach at AirGreen well

What we particularly appreciate about this installation is not just the machine’s technology.

This is how it could be integrated into a space where a conventional central configuration would have been much less practical.

The two modules side by side, the metal transitions, the compact refrigeration-line routing, the drainage, and the front access show the real work behind an electric furnace installation projects.

At AirGreen, we apply this same approach in our Blainville and the North Shore, as well as Montreal, Laval, Longueuil, and the South Shore : we choose the configuration based on the building, airflow, mechanical constraints, and heating needs, rather than forcing the building to adapt to a standard solution.

The MIDEA EVOX G3 is particularly interesting in this context because its modular design gives us several ways to solve a space constraint. But it is the quality of the sizing, sheet metal, connections, controls, and commissioning that turns this flexibility into real comfort for the homeowner.