Installation of a MIDEA EVOX G3 central heat pump in Saint-Laurent, Montreal

A central installation designed to withstand Montreal's climate without overlooking the outdoor details

In Saint-Laurent, Montreal, installing a MIDEA EVOX G3 central heat pump must address two very practical realities: providing heating when temperatures drop sharply and properly integrating the equipment into an existing home. In this AirGreen project, the photo of the outdoor installation shows several technical choices worth explaining, because these are precisely the details that can make the difference between a merely functional heat pump and a durable, accessible HVAC installation well suited to our climate.

The MIDEA EVOX G3 outdoor unit was installed on a raised metal structure secured near the foundation wall, rather than placed directly on the ground. The horizontal-discharge fan is oriented toward the open space in the yard, while the lines are grouped inside a light-colored line-hide that follows the home's exterior siding neatly.

The outdoor electrical disconnect installed near the equipment is also visible. The entire setup remains clear and accessible for maintenance while avoiding a bulky or disorderly installation around the heat pump.

Why outdoor positioning matters so much in Saint-Laurent

An outdoor heat pump unit should never be positioned solely according to where it is least visible.

In Montreal, we must take into account:

• snow accumulation around the unit;
• the clearance required for air intake and discharge;
• the water produced during defrost cycles;
• future access for maintenance and repairs;
• the routing of the refrigeration and electrical lines;
• the building's windows, air outlets, and other openings;
• the possible transmission of vibrations to the structure.

At this Saint-Laurent installation, placing the heat pump on a raised structure helps, among other things, prevent the unit's base from sitting directly at ground level.

The photo also shows small supports beneath the unit's feet. A stable, properly leveled installation is important because the equipment contains a compressor, fan, and refrigeration circuit that operate for long periods in both heating and cooling modes.

A horizontal-discharge unit well suited to residential spaces

The EVOX G3 installed here uses a large front-mounted fan with horizontal discharge.

This configuration is particularly useful when working along a residential wall or in an outdoor space where it is preferable to avoid a conventional unit that discharges air vertically through the top.

Midea explains that its outdoor design combines a horizontal-discharge fan with a vertical heat exchanger to provide uniform airflow through the heat exchanger.

On site, this design also facilitates certain installations where space is limited. However, this does not mean that a unit can be placed anywhere: the clearances specified for the exact model must always be respected.

A line set cover that is part of the job, not simply an aesthetic feature

A particularly visible detail of this installation is the horizontal routing of the white line set cover installed directly on the exterior siding.

The lines for a central heat pump generally include several components that must be protected and organized: insulated refrigerant piping, power supply, and control wiring, depending on the configuration used.

Leaving these elements exposed can result in a poor visual appearance and subject them more to the elements.

Here, the finish blends in with the residence's light-colored siding. This is the kind of detail we consider important at AirGreen: a central heat pump installation becomes part of the building for many years. It must therefore be technically correct, but also installed with care.

MIDEA EVOX G3: a central heat pump designed for extreme-cold heating

The main reason the MIDEA EVOX G3 line continues to attract attention in Quebec is its low-temperature operating capability.

According to the Midea technical documentation provided for this product line, the system can operate continuously down to -30 °C. Midea also indicates, based on tests of a three-ton system, up to 100% heating capacity at -25 °C, with a COP of approximately 1.9 under these conditions.

This is particularly relevant for a residence in Saint-Laurent, Montreal, where a central heat pump is not used solely as an air conditioner during the summer. It becomes an important part of the heating system for much of the winter.

The compressor technology described by Midea uses, among other things, intermediate-temperature vapor injection when outdoor conditions become very cold, in order to increase the total amount of compressed refrigerant and support heating capacity.

This obviously does not eliminate the need to size the installation properly. A high-performance machine at -25°C can nevertheless deliver unsatisfactory results if it is poorly selected for the building's actual thermal load.

Performance varies according to the exact capacity and match

The exterior photo identifies the MIDEA EVOX G3 family, but it does not reliably confirm the exact capacity of the installed unit.

We therefore prefer never to arbitrarily announce “3 tons,” “36,000 BTU,” or another capacity solely by observing the dimensions of the outdoor cabinet.

Midea's technical brochure presents several EVOX G3 configurations, including:

These values come from the configurations shown in Midea's performance table and must always be associated with the exact indoor/outdoor match selected.

In other words, simply writing “EVOX G3 up to 19 SEER2” is not enough to evaluate an actual installation. The complete combination must be examined and, where relevant, its AHRI number.

Sizing should never be based solely on the old heat pump

When replacing a central system, a common mistake is to automatically use the same tonnage as the old unit.

This shortcut can be problematic.

A house may have undergone several changes since its old system was installed: new windows, improved insulation, an addition, duct modifications, basement renovations, or changes to certain rooms.

At AirGreen, we therefore place importance on the heating and cooling load, the required airflow, and the actual capacity of the duct network.

An oversized central heat pump can have unsuitable cycles and poor humidity management. An undersized unit may run almost continuously when demand becomes high.

The right choice is not necessarily “the largest heat pump possible.” It is the system properly suited to the building.

A central system that is more than just the outdoor unit

The photo mainly shows the exterior part of the project, but a MIDEA EVOX G3 central system operates with an indoor unit connected to the residence's duct network.

The EVOX G3 design was specifically developed to facilitate the replacement and renovation of existing systems.

Midea offers, among other options, a modular air handler that can be configured in several orientations: upflow, downflow, left horizontal, right horizontal, as well as « low-boy » installations when available height is limited.

This is particularly useful in existing homes in Montreal, Laval, Longueuil, the North Shore, and the South Shore, where mechanical rooms were not necessarily designed for the dimensions of modern systems.

A design that can adapt to certain existing installations

The EVOX G3 also offers a multivoltage architecture for certain indoor units, with detection and adaptation to 115 V or 208/230 V, depending on the configuration. Midea also offers unit widths designed to match several typical dimensions of existing furnaces.

This can simplify certain conversion projects, but this flexibility should not be interpreted as permission to automatically keep all existing components.

We always check separately:

• the electrical supply;
• the wire gauge;
• the circuit breakers;
• the ducts;
• the plenum dimensions;
• the return air;
• the filtration;
• the thermostat;
• any potential auxiliary heating requirements.

Airflow deserves as much attention as tonnage

A high-end central system can lose much of its value if it is connected to an overly restrictive duct network.

Midea equips the EVOX G3 lineup with calculated constant-airflow technology, designed to adjust blower speed when static pressure varies. The documentation indicates an adaptation capacity of up to 1.2 in. of external static pressure, as well as airflow adjustment across up to 60 levels.

This feature can help the system handle different duct networks and different filters.

However, it does not replace proper duct design.

If a return-air system is severely undersized or several ducts are excessively restrictive, we prefer to correct the problem rather than ask the blower to compensate indefinitely.

MERV 13 filtration: multiple formats provided by Midea

EVOX G3 documentation also specifies compatibility with 1-, 2-, or 4-inch MERV 13 filters, depending on the module used. Midea indicates that this filtration can help capture more dust, pollen, particles, and pet hair or dander, while helping keep the evaporator cleaner.

However, filter selection must always be considered together with the system's static pressure.

A higher-performance filter is not useful if its installation reduces airflow so much that it impairs the heat pump's operation.

24 V control, 485 communication, and advanced communication options

The EVOX G3 is also designed to support different control architectures.

The manufacturer specifically mentions compatibility with 485 communication and 24 V thermostats, depending on the components selected. The system can also use Sub-1 GHz wireless communication between certain EVOX components to reduce the need for communication wiring in some applications.

This flexibility can be useful during a renovation, particularly when running a new cable between the indoor unit, thermostat, and outdoor unit would be complex.

R-454B refrigerant and the new generation of central systems

The EVOX G3 family presented in Midea's documentation uses R-454B refrigerant.

The manufacturer indicates a global warming potential, or GWP, of 466.

R-454B belongs to the A2L refrigerant category. Its use entails specific installation and service requirements that technicians must know and follow.

A R-454B heat pump should therefore not be considered a simple mechanical replacement for an older R-410A unit without verifying the applicable procedures, tools, and components.

What we check to ensure an EVOX G3 installation actually works as intended

A clean installation is not enough: commissioning is decisive

The exterior result of this Saint-Laurent project is clean, compact, and well integrated into the home, but much of the essential work is not visible in a photo.

During a central HVAC installation, our work must include a series of checks before the system can be considered complete.

Our approach to a central system project of this type

Depending on the building configuration, the main steps generally include:

1. Validate the required capacity based on the characteristics of the home.
2. Examine the existing ductwork system and available airflow rates.
3. Check the size of the return and supply ducts.
4. Position the indoor unit and adapt the plenums as needed.
5. Install the outdoor unit on a suitable base or structure.
6. Route and protect the refrigerant lines.
7. Complete the electrical connections in accordance with the equipment specifications.
8. Perform pressure tests and the vacuum procedure for the refrigeration circuit.
9. Configure the controls and thermostat.
10. Check operation in heating and cooling modes.
11. Measure the relevant airflow and static pressure parameters.
12. Confirm that condensate drains properly and that defrost cycles operate correctly.

These are the steps that turn a good piece of equipment into a good HVAC system.

Paying particular attention to defrosting during the winter

At low temperatures, a heat pump naturally accumulates frost on its outdoor coil.

It must periodically enter a defrost cycle.

During this process, water can collect beneath the unit. In Montreal’s climate, this water can then freeze.

This is one of the reasons why the height and immediate surroundings of an outdoor heat pump deserve particular attention. A unit installed too close to the ground may eventually become surrounded by snow and ice.

On the site shown here, the heat pump is clearly raised above the ground, creating more space beneath the unit.

The mistakes we seek to avoid with a central heat pump

Several problems we encounter in existing installations do not necessarily come from the heat pump brand.

They result from decisions made around the equipment.

Among the important mistakes to avoid:

• choosing the tonnage solely based on the old equipment;
• neglecting the ductwork;
• installing the outdoor unit too low in relation to the snow;
• placing the fan in front of an obstacle that is too close;
• neglecting future access to service panels;
• installing an overly restrictive filter without checking airflow;
• using an improperly configured thermostat or control logic;
• ignoring the need for auxiliary heating;
• advertising efficiency “up to” a certain value without verifying the actual AHRI pairing;
• assuming that a low-temperature heat pump will function perfectly simply because it has an operating rating of -30 °C.

The result always depends on the system as a whole: heat pump, air handler, ductwork, electrical supply, controls, settings, and installation quality.

And what about rebates for a MIDEA EVOX G3 in Saint-Laurent?

Eligibility for financial assistance should never be announced solely based on the name “MIDEA EVOX G3”.

The range includes several capacities and several pairings. To confirm eligibility for a program applicable in Quebec, you normally need to verify the indoor model, outdoor model, and exact AHRI number of the installed combination, then validate the program criteria in effect at the time of the project.

This is also the right way to compare two quotes.

Two contractors may list “MIDEA EVOX G3” on their proposals while offering different combinations.

Before signing, we therefore recommend requesting the complete model numbers and, when relevant, the corresponding AHRI reference.

A particularly relevant installation for homes with existing ductwork

For a Saint-Laurent property already equipped with a central system, the EVOX G3 offers several interesting features: operation at very low temperatures, modulation, an adaptable indoor unit and the ability to work with different control configurations.

This makes it a solution worth considering when replacing:

• an older central heat pump;
• a central air conditioner combined with a furnace;
• an older central electric system;
• or certain installations requiring an upgrade to the heating and air conditioning system.

The final choice must nevertheless be based on the house itself, not solely on the manufacturer's technical specifications.

The visible result of this AirGreen project in Saint-Laurent

This installation clearly illustrates our approach to a central heat pump in Montreal.

The outdoor unit is elevated, the air discharge is directed toward the open space, the lines are protected with a clean finish and the disconnect remains accessible.

None of these elements is spectacular on its own.

Taken together, however, they create a cohesive installation where the equipment does not look as though it was simply placed against the house in the easiest spot.

It is precisely this collection of details that matters when a system must operate every day for many years.

AirGreen installs MIDEA EVOX G3 systems in Greater Montreal

At AirGreen, we carry out central heat pump, air conditioning and heating projects in Saint-Laurent, Montreal, Laval, Longueuil, the North Shore and the South Shore.

For a MIDEA EVOX G3 project, we can assess the required capacity, compatibility with the existing ductwork, electrical configuration, controls, outdoor unit location and appropriate indoor/outdoor pairing.

A central heat pump represents a significant investment. Our goal is therefore to propose a configuration that truly suits the building and install it in a way that preserves its performance, accessibility and reliability.

To obtain a quote for a MIDEA EVOX G3 central heat pump installation in Montreal, Laval, Longueuil, on the North Shore or the South Shore, you can contact the AirGreen team directly.