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

In Pointe-Calumet, a precisely measured vertical installation where the modularity of the MIDEA EVOX G3 made it possible to work in an especially confined space

This installation of MIDEA EVOX G3 electric furnace in Pointe-Calumet perfectly illustrates a reality that technical specifications rarely show: in an existing home, choosing the right equipment is only the first part of the work. It must also be integrated properly into the available space, connected to the existing ductwork, and maintain reasonable access for future HVAC maintenance.

The photograph from our AirGreen job site is particularly revealing. The MIDEA EVOX G3 is installed vertically in a very narrow spacepractically enclosed by the walls. Above it, a large metal plenum extends the unit into the ceiling opening to connect with the existing air distribution network. On the front, the large black locking mechanisms between the different cabinet sections immediately reveal one of the most useful features of this generation of EVOX: its modular construction.

The cabinet rests on a base prepared for the installation, while its height uses almost the entire volume available up to the ceiling. In a project like this, a few centimetres can make the difference between a logical installation and a much more extensive reconstruction of the ductwork.

We therefore worked around three visible constraints: the limited width, the available height and the connection to the existing duct located directly above the equipment.

An electric furnace installed in a space where every centimetre had to be used intelligently

In Pointe-Calumet, as elsewhere on the North ShoreSeveral central system replacements take place in homes where the mechanical room was not designed for the dimensions of today’s equipment.

The situation photographed here is a good example. There is practically no wasted space around the cabinet. The new unit has a compact footprint, and its top connection integrates directly with the network already present in the building.

This type of installation requires considering the entire project before positioning the first section of the unit.

In particular, we need to check:

• the actual width available between the walls;
• the height up to the main duct;
• the ability to move the different sections into their final position;
• access to the service panels;
• how to manufacture or adapt the supply plenum;
• airflow through the existing network;
• the location of the refrigerant, electrical, and drainage connections;
• the ability to remove the panels later during maintenance.

On this installation at Pointe-Calumet, the top connection is especially important. The plenum rises immediately toward the ceiling and passes through the prepared opening to connect to the existing ducts. This makes it possible to preserve the system's overall layout without unnecessarily taking up more space in the room.

The EVOX G3's “Block N Lock” modular design is particularly meaningful here

The large black fasteners visible on the front are not merely an aesthetic detail.

The MIDEA EVOX G3 uses a modular construction designed to facilitate transporting, assembling, and reconfiguring the unit. The manufacturer provides six installation options, including vertical, downflow, right- and left-horizontal configurations, as well as low-boy configurations. MIDEA also points out that this architecture facilitates handling in difficult locations such as basements and attics.

In our Pointe-Calumet project, this advantage becomes very tangible.

A traditional cabinet manufactured as one large section can be difficult to move through a narrow passage or stand upright beneath a ceiling already occupied by ducts. With a unit made up of modules, we can manage handling on-site much more effectively and then assemble it in the designated space.

MIDEA also describes its system as a solution that allows simplified module reconfiguration and use in a low-boy configuration when height restrictions require it.

In this photo, the connection between the modules and their locks is clearly visible. This is a real example of how a design feature can facilitate the installation of an electric furnace in an existing home.

A cabinet designed to facilitate the replacement of older central furnaces

Another interesting feature of the EVOX G3 is its width.

MIDEA indicates that the different capacities in the range use cabinets approximately 14.5 to 21.5 inches wide, to better match the standard dimensions of older central furnaces. The indoor platform is also designed to accommodate different power supplies, including 115 V and 208/230 V depending on the configuration.

For a replacement such as this one Pointe-Calumet, this can considerably reduce the work required.

This does not mean that a new furnace can be installed without modification simply because its width is similar to that of the old unit. The plenum, return air, and transition must always match the required airflow.

But when the cabinet width is compatible with the available space, we can sometimes avoid having to:

• moving a partition;
• rebuilding a significant section of ductwork;
• enlarging a mechanical closet;
• relocating other equipment;
• compromising access to the panels.

The photograph clearly shows this benefit: the new appliance makes use of almost exactly the space available to it.

Why we refer to an “electric furnace” even though the EVOX G3 is also an air handler

For a Quebec homeowner, the indoor unit of a central system is generally called an electric furnace.

In the case of the EVOX G3, however, it is useful to clarify its technical role.

This unit forms the indoor core of a central system: it contains the fan and the heat exchanger required to operate with a central heat pump. An auxiliary electric heating system can be integrated to provide additional heat when conditions or demand require it.

MIDEA provides a three-stage auxiliary heating system capable of up to 25 kW. According to the manufacturer, the different stages allow activation suited to changing temperatures and more precise management of electric heating.

However, it would be incorrect to conclude that all homes should receive 25 kW of auxiliary heating.

At AirGreen, the appropriate capacity depends in particular on:

Of the building’s heating requirements

A compact, well-insulated home does not have the same heat loss as a larger, older property.

Of the selected outdoor heat pump

A heat pump capable of maintaining high capacity at low temperatures can reduce reliance on resistance heating.

Of the existing electrical installation

An electric element represents a significant load. The electrical panel and power supply must be able to support the selected configuration.

A larger electric heater is therefore not automatically a better heater.

A range designed to operate at very low temperatures

The EVOX G3 is part of the new generation of MIDEA central systems developed for heating in cold climates.

In its documentation, MIDEA announces continuous operation down to -30 °C. For a three-ton system used during its tests, the manufacturer also indicates up to 100% heating capacity at -25 °C, with a COP of approximately 1.9 under the stated test conditions.

For Pointe-Calumet and Montreal’s North Shore, this low-temperature operating capacity is obviously important.

However, we avoid a common mistake when comparing heat pumps: taking data obtained with one particular model and applying it to an entire series.

The exact capacity at -15 °C, -20 °C, or -25 °C must be verified with the exact combination of the indoor and outdoor units.

An EVOX G3 family covering multiple capacities

MIDEA's technical table covers several system sizes, including:

• 18,000 BTU/h;
• 24,000 BTU/h;
• 30,000 BTU/h;
• 36,000 BTU/h;
• 48,000 BTU/h;
• 54,000 BTU/h.

In the photograph of this Pointe-Calumet installation, no legible nameplate allows us to identify the unit's exact capacity with certainty. We therefore prefer not to artificially assign a BTU rating to this installation.

This is also important advice for anyone comparing a quote for a MIDEA central heat pump.

Do not settle for the mention “EVOX G3.” Always ask for:

• the exact indoor unit model;
• the exact outdoor unit model;
• the rated capacity;
• the low-temperature heating capacity;
• the AHRI number;
• the combination's SEER2 and HSPF2 ratings;
• the capacity of the installed electric element.

Up to 19 SEER2: why the words “up to” matter

Depending on the combinations presented by MIDEA, the EVOX G3 lineup achieves performance ratings of up to 19 SEER2, 12.5 EER2, 10.8 HSPF2 and a COP of up to 2.14 at 5°F, or approximately -15°C.

Not all capacities have these same figures.

The technical table shows, for example, a 30,000 BTU combination with 17.2 SEER2 and 10.8 HSPF2, while a 36,000 BTU combination is listed at 17.7 SEER2 and 10.0 HSPF2. The 48,000 and 54,000 BTU systems have other values as well.

For us, this precision is essential. When we present an HVAC installation, we want to discuss the system that was actually installed rather than use the best rating available in an entire brochure as if it automatically applied to every home.

The invisible challenge: connecting a new EVOX G3 to existing ductwork without sacrificing airflow

The large upper plenum visible in the photo is not simply a piece of sheet metal

One of the most striking elements of this Pointe-Calumet installation is the large metal fitting located above the furnace.

It rises to the ceiling to connect to the existing duct system.

A transition of this type must provide sufficiently smooth airflow. If it becomes too narrow or includes poorly designed changes in direction, static pressure increases and the fan has to work harder.

That is why we always consider the furnace and ductwork as a single system.

A highly efficient unit on paper can deliver poor results when connected to an overly restrictive duct system.

Computational Constant Airflow 2.0 technology into the EVOX G3: a useful technology when existing ductwork is retained

MIDEA integrates its Computational Constant Airflow 2.0.

The documentation explains that the fan can adjust its output and speed when network conditions change. The manufacturer's examples show operation of up to 1.2 in. of external static pressure, while maintaining airflow under the conditions shown.

The system also offers up to 60 airflow-volume adjustment levels.

In an existing home in Pointe-Calumet, this provides useful adjustment range during commissioning.

We can better adapt operation to the network's actual characteristics rather than limiting ourselves to a few fixed speeds.

But this technology never exempts us from checking the ductwork.

If the return-air opening is far too small, a duct is crushed, or a metal transition creates a major restriction, the problem must be corrected. Electronics do not replace proper mechanical sizing.

More effective filtration must also comply with airflow requirements

The EVOX G3 range can accommodate, with the appropriate module, 1-, 2-, or 4-inch MERV 13 filters. According to MIDEA, this filtration captures more dust, pollen, and other particles while helping keep the evaporator cleaner.

However, we recommend never choosing a filter solely because it has a high MERV rating.

The filter's surface area and resistance must be suited to the furnace's airflow.

In a compact installation such as the one in Pointe-Calumet, the filter location must also remain accessible. A system requiring a piece of furniture to be moved or a section of ductwork to be dismantled every time the filter is replaced would be poorly designed for daily use.

R454B: the EVOX G3's new-generation refrigerant

The EVOX G3 platform uses R454B refrigerant, classified as A2L. MIDEA indicates a global warming potential, or GWP, of 466 for this refrigerant.

This evolution affects installation and service methods.

Technicians must use the appropriate procedures and equipment for R454B, particularly when making refrigerant connections, checking for leaks, evacuating the system, and commissioning it.

A high-performance heat pump still depends on the quality of the refrigerant circuit created on-site.

LogisVert: check the complete system before announcing an amount

For an installation carried out in 2026, it is important to check the program's current rules Hydro-Québec's LogisVert rather than relying on outdated amounts.

Hydro-Québec currently specifies that installed heat pumps as of November 26, 2025, must be ENERGY STAR certified to be eligible. The organization also asks users to consult its official tool to verify whether the installed combination appears on the list of eligible heat pumps.

The application must normally be submitted no later than nine months after the equipment installation date.

In the case of this installation of Pointe-Calumet, we do not publish a specific amount because the photo mainly shows the indoor furnace and does not make it possible to identify the complete indoor unit/outdoor unit combination with certainty.

It is this complete combination, together with the applicable references, that must be used to confirm eligibility.

The mistakes this installation specifically helps avoid

An installation this compact shows why several decisions must be made before the unit arrives.

Choosing the furnace based solely on its capacity

Capacity is essential, but so are the the cabinet's physical dimensions are as well when work must be done between two walls and beneath an existing system.

Underestimating the required height

The furnace is not the only element that occupies vertical space. The transition and the connection plenum to the system must also be taken into account.

Building a transition that is too restrictive

A sharp reduction can increase static pressure and impair airflow.

Making the panels impossible to open

In a tight installation, we must consider future maintenance from the moment the unit is positioned.

Automatically copying the old equipment's tonnage

An old furnace may have been oversized. The new selection must match the building's actual needs.

Assuming that an EVOX G3 is automatically eligible for a given rebate

The exact combination and the program criteria at the time of installation must always be verified.

This Pointe-Calumet project effectively summarizes our approach at AirGreen

What we remember most about this MIDEA EVOX G3 electric furnace installation in Pointe-Calumet, is how a modern unit can be integrated into a location that offers very little room for maneuver.

The photo shows a cabinet almost entirely recessed into its surroundings, a direct top connection to the ducts, and the modular attachments characteristic of the EVOX G3. The real value of the project lies precisely in this integration accuracy.

At AirGreen, we carry out this type of electric furnace replacement and central heat pump installation to Montreal, Laval, Longueuil, the North Shore, and the South Shore.

Our goal is not simply to fit a new machine into the space left by the old one. We seek to achieve a cohesive installation as a whole: proper capacity, correctly adjusted airflow, a well-designed duct connection, preserved service access, and a compatible electrical configuration.

In a large mechanical room, certain mistakes can be corrected by adding space. In an installation as tight as this one in Pointe-Calumet, the planning must be right from the start.

This is where the modular design of the MIDEA EVOX G3 and the practical experience of a team accustomed to existing homes in Greater Montreal become particularly useful.