Installation of a MIDEA EVOX G3 central heat pump in Notre-Dame-de-l’Île-Perrot

A MIDEA EVOX G3 installation in a narrow masonry space: when positioning becomes just as important as the machine

At Notre-Dame-de-l’Île-Perrot, we carried out this installation of a MIDEA EVOX G3 central heat pump in an outdoor configuration that requires much more thought than simply choosing an open location on the side of a house.

The construction photo immediately shows the main distinctive feature: the outdoor unit is located in a relatively narrow space bounded by two brick walls, with a door immediately nearby on the right side. The condenser was therefore installed high up on metal brackets secured to the foundation, rather than placed directly on the ground.

This choice meets several objectives simultaneously. It was necessary to preserve the passage in front of the unit, avoid further obstructing this walkway, keep the heat pump high enough for winter conditions, and allow the large front fan to discharge air toward the open area in front of it.

This is precisely the kind of installation where a difference of just a few inches in positioning can affect accessibility, winter operation, and the ease of HVAC maintenance in the years that follow.

The MIDEA EVOX G3 is an Inverter central system designed by Midea for ducted applications. The technical brochure presents it as a range developed specifically to improve heating performance, energy efficiency, and integration into existing installations.

A raised condenser in a narrow passage: a very practical choice

At this installation in Notre-Dame-de-l’Île-Perrot, the outdoor unit is not installed just a few inches above the ground.

It is placed on two metal arms that hold it at a considerable height above the foundation. The bottom of the unit thus remains completely unobstructed.

For a central heat pump that must heat during Quebec winters, this detail is far from secondary.

When a heat pump operates in heating mode in cold weather, its outdoor coil may accumulate frost. The unit then periodically initiates a defrost cycle. The water produced by this process must be able to drain beneath the unit before freezing.

In an installation that is too low, this water can gradually contribute to significant ice buildup beneath the condenser.

Snow naturally adds to this.

In Notre-Dame-de-l’Île-Perrot, as in Montreal, Laval, Longueuil, on the North Shore and the South Shore, we must consider the likely level of accumulation around the unit before determining its final height.

Why this height is particularly relevant with an EVOX G3

The Midea brochure states that the Extreme Heat range offers continuous operation down to -30 °C. Under the manufacturer's test conditions, it also indicates up to 100% heating capacity at around -25 °C, with a COP reaching approximately 1.9.

In other words, this heat pump is specifically designed to keep operating when outdoor conditions become difficult.

It would therefore be contradictory to install a machine capable of operating at very low temperatures in a position where a normal accumulation of snow or ice could quickly reduce its clearances.

For this installation, we specifically chose an elevated installation to preserve functional space beneath the condenser.

The space between two walls completely changes the positioning strategy

The photo shows that we did not have a large open area around the equipment.

The rear wall supports the heat pump. A second brick wall is on the right. A door is installed on this same side, and several building elements already occupy this area.

In a space like this, we must specifically assess:

• the fan orientation;
• the distance from the walls;
• access to the service panels;
• the clearance in front of the heat pump;
• the passage of the refrigerant lines;
• the electrical connection;
• the flow of defrost water;
• the space needed by a technician for future servicing.

The fact that a heat pump physically “fits” in a space does not automatically mean that the location is suitable.

The horizontal discharge of the EVOX G3 makes perfect sense here

The MIDEA EVOX G3 uses a large front-mounted horizontal-discharge fan.

The manufacturer's documentation describes a design combining a horizontal-discharge fan and a high-efficiency vertical heat exchanger. Midea indicates that this architecture is intended to provide more uniform airflow across the heat exchanger's surface and better performance as the outdoor temperature drops.

In this narrow yard, this format is interesting because the air is discharged toward the open area in front of the unit rather than directly upward or toward the wall behind it.

Naturally, we must keep the front area clear. A heat pump must not be used as a storage surface, and its fan must not be blocked by objects, snow, or other obstacles.

The brick wall requires an appropriate attachment

This installation is also notable for its support.

The outdoor cabinet of a central heat pump can be relatively heavy depending on its capacity. The unit must therefore be supported by a suitable structure, with appropriate attachment to the building's available structural component.

In the photograph, the unit is supported by two separate metal brackets, each connected to the foundation. The MIDEA's feet rest on the horizontal ends of the brackets.

This arrangement keeps the heat pump completely clear of the ground while avoiding the installation of a large freestanding structure in the passageway.

The EVOX G3 is available in several capacities: the tonnage should not be invented from a photograph

The MIDEA EVOX G3 is not a single fixed-capacity machine.

The technical brochure presents a range from approximately 18,000 to 54,000 BTU/h, with efficiencies that vary depending on the indoor/outdoor combination. Midea announces up to 19 SEER2, 12.5 EER2, 10.8 HSPF2, and a COP at 5 °F of up to 2.14 for the range, depending on the configuration.

The listed Extreme Heat combinations include, among others:

• MAUSE-H18B-2A + MO1HE-H18B-2A;
• MAUSE-H24B-2A + MO1HE-H24B-2A;
• MAUSE-H30B-2A + MO1HE-H30B-2A;
• MAUSE-H36B-2A + MO1HE-H36B-2A;
• MAUSE-H48B-2A + MO1HE-H48B-2A;
• MAUSE-H60B-2A + MO1HE-H60B-2A.

The photograph of Notre-Dame-de-l’Île-Perrot does not allow us to read the unit’s complete model number with certainty. We therefore cannot honestly assign a precise tonnage to this installation based solely on this image.

For us, this precision is important. A serious technical installation should never turn an assumption into an official specification.

The precise efficiency ratings change according to the selected capacity

The Midea table clearly shows these differences.

For the Extreme Heat combinations presented in the brochure:

• the 18,000 BTU system is rated at 19 SEER2, 12.5 EER2, and 10.1 HSPF2;
• the 24,000 BTU at 18.6 SEER2, 12 EER2, and 10 HSPF2;
• the 30,000 BTU at 17.2 SEER2, 12 EER2, and 10.8 HSPF2;
• the 36,000 BTU at 17.7 SEER2, 12 EER2, and 10.0 HSPF2;
• the 48,000 and 54,000 BTU configurations are listed at 17.5 SEER2 and 9.5 HSPF2.

These data show why we size a central heat pump according to the home rather than according to the “as large as possible” logic.

A properly selected system must match the heating load and the available ductwork.

Cold-weather heating also depends on compressor technology

The EVOX G3 brochure describes the compressor's M-Powevi technology.

Midea explains that under extreme cold conditions, the system injects vapor at an intermediate temperature to increase the total amount of compressed refrigerant and support heating performance.

The manufacturer also mentions, for a test conducted on a three-ton system, up to 118% of nominal capacity at approximately -25 °C, with a COP of 1.92 under the stated laboratory conditions.

We interpret these figures as characteristics specific to the specified test conditions, not as a universal value that automatically applies to every EVOX G3 and every home.

That is precisely why choosing the complete system remains essential.

What the photo does not show: the role of the ductwork, indoor unit, and controls

Computational Constant Airflow 2.0 and existing ductwork

A central heat pump cannot be evaluated solely by looking at its outdoor unit.

The indoor unit must move enough air through the ductwork to transport energy to every room.

Midea equips the EVOX G3 with Computational Constant Airflow 2.0 technology. The brochure presents an ability to adapt to different ductwork and filtration conditions, with static pressure reaching approximately 1.2 in. water column in the examples provided. It also indicates up to 60 levels of airflow customization.

For a replacement project, this is particularly useful.

An existing duct system may have restrictions that a new system must be able to manage intelligently.

However, this does not mean that poor ductwork can be ignored. When the ducts are genuinely undersized, the solution remains to correct the air distribution rather than asking the fan to compensate indefinitely.

A modular indoor unit suited to renovations

The EVOX G3 uses a modular indoor architecture.

Midea presents six installation configurations, including:

• upflow;
• downflow;
• right horizontal;
• left horizontal;
• two low-boy configurations.

The “Block N Lock” design allows the modules to be reconfigured to adapt the unit to certain difficult spaces.

In an existing home, this aspect can make a big difference.

A mechanical room was not always designed to accommodate a new generation of air handler. You may sometimes have to contend with a low basement, a narrow door, a return located on the wrong side, or other equipment installed around the system.

Dimensions designed to facilitate certain furnace replacements

Midea also presents the EVOX G3 as a platform suitable for replacing certain existing furnaces.

Depending on capacity, the indoor units use widths of approximately 14.5 to 21.5 inches. The manufacturer also mentions multivoltage indoor compatibility with 115 V and 208/230 V.

This can reduce certain renovation challenges, but a complete verification is still necessary.

We still need to confirm:

the ductwork,
the sheet metal transitions,
the electrical panel,
the electrical protection,
the return air,
and auxiliary heating requirements.

Up to 25 kW of auxiliary heating

The Midea brochure specifies auxiliary electric heating elements of 10 kW, 15 kW, and up to 25 kW, with three-stage operation in the configuration described.

This supplemental heat must be sized for the project.

An oversized auxiliary heater can impose an unnecessarily high electrical load. An undersized unit may not provide the desired support under extreme conditions.

The right choice depends on the home's heat loss, the heat pump's tonnage, and the available electrical capacity.

485, 24 V, and existing thermostat controls

The EVOX G3 offers different control options.

According to Midea documentation, the system is compatible with 485 communication and traditional 24 V controls. The manufacturer also provides for certain configurations using third-party thermostats.

This flexibility can simplify a replacement when a home already has usable thermostat wiring.

With Midea's connected ecosystem, the manufacturer also presents the SmartHome app, schedule programming, energy-consumption tracking, and certain self-diagnostic or remote-update functions.

MERV 13 filtration and static pressure: two topics that must be addressed together

Midea indicates compatibility with 1-, 2-, and 4-inch filters, including MERV 13 in the illustrated module.

More efficient filtration can capture more dust, pollen, particles, and pet hair.

However, it does add resistance to airflow.

We therefore never recommend a filter solely because its MERV rating is higher. We must confirm that the ductwork and blower can maintain the required airflow.

R-454B in the EVOX range

The brochure indicates that Midea chose R-454B for this product range. The manufacturer classifies it as an A2L refrigerant and indicates a GWP of 466.

For an HVAC company, this evolution requires procedures and equipment suited to this generation of refrigerant.

For the homeowner, the main thing to understand is that a recent EVOX G3 is not simply the direct equivalent of an older heat pump in terms of refrigeration technology.

LogisVert grant: what the documentation actually supports

The Midea brochure indicates that the range presented exceeds the ENERGY STAR Most Efficient specifications mentioned by the manufacturer.

However, the document provided contains no LogisVert eligibility list, no Hydro-Québec financial assistance amount and no Quebec-specific confirmation related to this specific installation in Notre-Dame-de-l’Île-Perrot.

We therefore cannot confirm a subsidy based on this brochure alone.

To determine actual eligibility, the exact combination installed and the program criteria applicable to the project must be checked separately.

Mistakes to avoid in a location like Notre-Dame-de-l’Île-Perrot

Installing the heat pump too low

In this enclosed space, an accumulation of snow or ice would quickly have reduced the clearance available around the unit.

Neglecting service space

The proximity of the two walls requires consideration of how a technician will access the unit later.

Blocking the front discharge

The large fan must have a clear area in front of it.

Installing the equipment without considering the nearby door

The presence of the door on the right is a permanent building constraint. The installation must not interfere with its use.

Choosing the capacity solely according to the floor area

The right capacity depends on the heat load and the ductwork, not on a simplified rule based solely on square footage.

A central installation adapted to the actual home

This installation in Notre-Dame-de-l’Île-Perrot is interesting because it shows a heat pump installed in an environment much more representative of our daily work than a catalogue photo.

Two brick walls. A foundation. A door. A relatively narrow area. A need for space beneath the unit. A central machine that must remain accessible and continue operating throughout the winter.

We therefore used the vertically available space rather than unnecessarily taking up floor space.

The MIDEA EVOX G3 provides a complete technical platform: Inverter technology, heating in extremely cold weather, a modular indoor unit, advanced airflow management, compatibility with different control strategies and R-454B refrigerant.

But these features only have value when they are properly integrated into the building.

At AirGreen, it is this combination of sizing, mechanical installation, air circulation, accessibility, finishing and commissioning that we seek to reproduce in our central heat pump projects in Notre-Dame-de-l’Île-Perrot, Montreal, Laval, Longueuil, on the North Shore and on the South Shore.