Installation of a MIDEA EVOX G3 Extreme Heat central heat pump in Saint-Bernard-de-Lacolle, Montérégie

In Saint-Bernard-de-Lacolle, a central installation designed for both extreme cold and the realities of the building

For this installation completed in Saint-Bernard-de-Lacolle, near the U.S. border and south of Montreal, one detail immediately stands out: the outdoor MIDEA EVOX G3 unit was not simply placed at ground level. We installed it on a raised wall-mounted metal bracket, at the corner of the home, between a brick wall and vinyl siding.

This choice tells an important part of the project’s story. When a central heat pump must provide a significant portion of a Quebec home’s heating, its outdoor installation must account for snow accumulation, defrost cycles, service access, and airflow around the unit. In Saint-Bernard-de-Lacolle, where winter conditions can be harsh, these considerations are not secondary.

The photo taken at our job site also shows the electrical disconnect installed nearby, the refrigerant connections on the side of the unit, the insulated bundle entering the house, and the clearance maintained around the condenser. The heat pump is located in a relatively confined space between two façades, which required careful consideration of its orientation before permanently securing the bracket.

The installed model belongs to the new generation of MIDEA EVOX G3 inverter-technology central systems, a range designed to operate with a duct network and a central air-handling unit. MIDEA specifically presents the EVOX G3 as a ducted central system intended to facilitate upgrades to existing systems while improving low-temperature heating performance.

Why the outdoor placement was particularly important for this home

At first glance, the chosen location seems simple: an open space along the foundation. In practice, several constraints come together in the same spot.

The house combines masonry and vinyl siding, a wall outlet is located nearby, and the route of the lines to the interior had to remain relatively short. We also had to preserve access to the heat pump's service compartment.

We therefore positioned the equipment so that its large horizontal discharge fan could expel air without being directly enclosed against the facade.

This horizontal design is also one of the technical features highlighted by MIDEA for the EVOX G3. The manufacturer combines a horizontal discharge fan with a vertical heat exchanger to achieve more uniform airflow across the surface of the heat exchanger.

For a homeowner, this highlights an essential rule: the best location for a central heat pump is not necessarily the place where it is least visible. We must also consider airflow, snow, service access, building openings, the route of the refrigerant lines, and potential vibrations.

Why we raised the MIDEA EVOX G3

The metal structure visible in the photo keeps the unit well above the ground.

This is particularly relevant for a cold-climate heat pump. During the winter, the equipment extracts heat from the outdoor air. Frost naturally forms on the coil, and the system periodically initiates a defrost cycle. The resulting water must be able to drain away without gradually encasing the base of the equipment in ice.

A unit placed too close to the ground can also become partially obstructed after a heavy snowfall or when snow accumulates during snow removal.

The support must therefore fulfill several functions simultaneously: keep the equipment stable, provide appropriate winter clearance, limit vibration transmission, and maintain suitable geometry for the connections.

For this installation in Saint-Bernard-de-Lacolle, we also used supports beneath the unit to create a clean interface between the condenser and its metal structure.

EVOX G3: performance that goes well beyond that of a traditional central air conditioner

The fundamental difference between this system and an older central air conditioner lies in its ability to provide heating and cooling from the same equipment, with inverter modulation.

MIDEA’s documentation presents the EVOX G3 as a platform offering continuous heating operation down to -30 °C. For the tests presented on a three-ton MIDEA system, the manufacturer also indicates up to 100% of rated heating capacity at -25 °C, with a COP of approximately 1.9 under those conditions.

The manufacturer explains that its compressor technology uses, among other things, intermediate-temperature vapor injection when outdoor temperatures become very low, in order to increase the amount of compressed refrigerant and support heating performance.

For a Quebec home, this low-temperature performance is much more significant than simply having a high SEER2 rating.

A heat pump can be extremely efficient in spring and fall, but its ability to continue producing heat when temperatures plunge determines a large part of its value as a true heating system.

Up to 19 SEER2 and 10.8 HSPF2 depending on the selected capacity

The EVOX G3 line covers various capacities. The MIDEA brochure presents systems ranging approximately from 18,000 to 54,000 BTU/h and, depending on the combination, advertises performance 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.

The product line’s technical sheet shows, among others, the following configurations:

These values come from the EVOX G3 technical table provided by MIDEA.

The exact capacity of the system at this site cannot be read from the provided photo; we therefore prefer not to artificially assign a precise output to this installation. The actual sizing of a central heat pump must always be confirmed based on the exact model and the home’s heating requirements.

Rated capacity is not the only figure that matters

When a homeowner compares a 2-, 2.5-, 3-, 4-, or 5-ton heat pump, it is tempting to choose the unit with the highest capacity.

That is not our approach.

An undersized heat pump may lack capacity during difficult periods. An unnecessarily oversized unit may, conversely, make air and humidity management less optimal and create operating cycles that do not match the characteristics of the building.

In a central HVAC installation, we must consider the floor area, heat loss, insulation level, windows, solar exposure, ductwork, available airflow, and the needs of the different rooms simultaneously.

The advantage of an inverter system such as the EVOX G3 is precisely its ability to modulate its operation rather than being limited to simple on-off operation.

Another key component of the project is located indoors: the EVOX G3 air handler

The photo naturally shows the outdoor equipment, but a ducted central heat pump is a system. Inside, the air handler circulates heated or cooled air through the ductwork.

This is where MIDEA introduced several interesting changes with the third-generation EVOX.

The manufacturer offers a modular design called Block N Lock, intended to simplify transporting and reconfiguring the unit. The module can be adapted to six positioning types: upward discharge, downward discharge, horizontal right, horizontal left, as well as “low-boy” configurations for locations where ceiling height is limited.

This flexibility has real value in homes in Montreal, Laval, Longueuil, the South Shore, and the North Shore, where we regularly encounter narrow mechanical rooms, finished basements, and existing installations that are difficult to modify.

A design intended for replacing existing equipment

MIDEA has also worked on the dimensions of its indoor units to facilitate the replacement of older furnaces.

The documentation indicates widths ranging from approximately 14.5 to 21.5 inches, corresponding to the common sizes of several residential furnaces. The EVOX G3 air handler can also recognize and adapt to a 115 V or 208/230 V power supply, depending on the applicable configuration.

This does not mean that a replacement automatically becomes simple. We still need to assess the duct transitions, electrical supply, return air, drain, auxiliary heating, and service clearance.

But when equipment is designed from the outset to fit standard furnace dimensions, we have more options for producing a clean installation without unnecessarily rebuilding the entire mechanical room.

Up to 1.2 in. of static pressure and airflow that adapts to the ductwork

The ductwork can determine the actual performance of a central system just as much as the heat pump itself.

Undersized ducts, a highly restrictive filter, or a dirty coil increase resistance to airflow. A unit that cannot compensate for this resistance may then deliver less airflow than expected.

MIDEA uses its Computational Constant Airflow 2.0 technology on the EVOX G3. According to the manufacturer, it can adjust the motor output and fan speed to better maintain the required airflow when static pressure varies. The documentation indicates a capacity of up to 1.2 in. of water column static pressure, with up to 60 airflow adjustment levels.

For our technicians, this adjustment capability is useful during commissioning. We do not simply start up the unit: the airflow must match the actual system in which the heat pump is installed.

Auxiliary heating: up to 25 kW depending on the configuration

Even an excellent cold-climate heat pump can be paired with auxiliary heating.

For the EVOX G3, MIDEA offers a three-stage auxiliary electric element that can reach 25 kW, depending on the capacity and configuration. The system can activate and adjust these stages according to temperature requirements.

The goal is not to operate the electric elements continuously. Rather, a properly adjusted configuration seeks to maximize the heat pump’s operation and use supplemental heat when the home’s thermal load or outdoor conditions genuinely require it.

This is particularly important in Quebec, since the control strategy can have a direct effect on consumption during cold periods.

R-454B: the new refrigerant for the EVOX G3 product line

The EVOX G3 system uses R-454B, an A2L-category refrigerant.

MIDEA states that it selected R-454B for its product line and gives a global warming potential, or GWP, of 466.

For the owner, this change is often invisible. For the installer, however, it entails important requirements regarding tools, refrigerant handling, work methods, and commissioning procedures.

The visible refrigeration connections on the side of the unit in our photo from Saint-Bernard-de-Lacolle illustrate one of the phases that requires the most rigor: line preparation, connection, leak testing, evacuation, and system validation before normal operation.

This project shows why a central heat pump must be designed as a complete system

Refrigeration lines: a few visible feet, but a lot of work behind them

In the photo, the copper tube and the insulated bundle connecting the heat pump to the building are clearly visible.

This part may seem simple. However, the quality of a refrigeration installation depends on details that are almost never visible once the work is complete: pipe bend radius, connection quality, insulation protection, leak testing, evacuation, and compliance with the lengths specified by the manufacturer.

We also plan the exit through the wall to limit unnecessary runs and maintain access to the service valves.

This photo was taken at a stage when the connections are still visible, which makes it possible to understand what is normally behind the finish of a central heat pump installation.

The electrical disconnect remains accessible

To the right of the heat pump, the electrical disconnect is installed directly on the exterior siding.

Its accessibility is essential for maintenance and technical work. A technician must be able to electrically isolate the unit before certain work.

In a professional installation, we also seek to organize the wiring logically and avoid having a future intervention on the condenser require the removal of several components unrelated to the service.

24 V compatibility, 485 communication, and wireless control

The EVOX G3 offers several communication methods. MIDEA documentation indicates compatibility with a 485 communicating system, a conventional 24 V thermostat, and a wireless communication solution using Sub-1 GHz modules between certain EVOX components.

This flexibility is useful during a replacement, since not all homes have the same thermostat wiring.

However, this does not mean that just any thermostat will provide access to all advanced features. The MIDEA communicating controller may offer additional capabilities related to system diagnostics and modulation.

MERV 13 filtration and air quality

Depending on the installation, the EVOX G3 filtration module can accept 1-, 2-, or 4-inch MERV 13 filters. MIDEA states that this filtration can capture more dust, pollen, particles, and pet hair or dander while helping keep the evaporator cleaner.

However, we must always verify that the selected filter matches the actual ductwork system. Installing a more restrictive filter without considering airflow is not automatically an improvement. Static pressure and airflow must be measured and adjusted accordingly.

Smart control and consumption monitoring

With the MIDEA communicating thermostat and the SmartHome app, the platform provides scheduling, comfort control, electricity consumption monitoring, and certain diagnostic or remote update functions.

For an inverter central system, this information can be useful because its operation is not always as obvious as that of an older furnace that started and stopped abruptly.

A variable-capacity heat pump can operate longer at low output. This behavior is generally intentional: it aims to maintain a stable temperature rather than waiting for a significant temperature drop before restarting at full capacity.

LogisVert: What financial assistance is available for a MIDEA EVOX G3 in Quebec?

For an installation carried out in Quebec in 2026, eligibility must never be determined solely from the MIDEA logo or the EVOX G3 commercial name.

Hydro-Québec currently indicates that a cold-climate ENERGY STAR-certified heat pump may receive, under the LogisVert program, financial assistance of $120 per 1,000 BTU/h of recognized heating capacity at -8 °C, when all program conditions are met. The applicable amount is determined according to the installation date.

The final amount therefore depends on the exact combination of outdoor and indoor units, its certification reference, and its recognized heating capacity at -8 °C.

That is why we check the eligible combination rather than calculating a rebate simply from the number of tons listed on a quote.

Five points we check before considering an installation complete

For a MIDEA EVOX G3 central heat pump, our work does not stop when the condenser starts up. We pay particular attention to the following elements:

• outdoor unit position and clearances, particularly for snow and defrosting;
• refrigerant circuit leak-tightness and evacuation before commissioning;
• airflow and static pressure in the ductwork;
• thermostat and auxiliary heating configuration, to avoid unnecessary use of the electric resistance heaters;
• drainage, electrical supply, filtration, and service access, all of which will affect long-term reliability.

These checks are particularly important when modernizing an older central system. Reusing existing ductwork can be an excellent solution, but only when its condition, sizing, and distribution are suitable for the new equipment.

What we learned from our EVOX G3 installation in Saint-Bernard-de-Lacolle

This project clearly shows that a successful central HVAC installation depends just as much on the choice of equipment as on the decisions made around it.

In Saint-Bernard-de-Lacolle, we had an outdoor location to integrate between two façade materials, a climate where snow accumulation must be taken seriously, and a central system designed to continue heating when temperatures drop very low.

The raised wall bracket, fan orientation, access to the service valves, electrical disconnect, and relatively direct routing of the lines all contribute to the result.

The MIDEA EVOX G3 adds an interesting combination of technologies to this installation: inverter compressor, heating rated down to -30 °C, efficiency of up to 19 SEER2 depending on capacity, adjustable constant airflow, modular indoor unit, MERV 13 filtration, compatibility with various control strategies, and R-454B refrigerant.

For us at AirGreen, this type of project reflects exactly what a central heat pump should be: not simply an appliance installed against a home, but a solution in which the outdoor unit, indoor unit, ductwork, electrical system, controls, and auxiliary heating have been designed as one integrated system.

We carry out this same type of central heat pump installation in Montreal, Laval, Longueuil, the South Shore, the North Shore, and throughout Greater Montreal, with particular attention to sizing, winter performance, and quality workmanship.