Installation of a MIDEA EVOX G3 central heat pump in Saint-Stanislas-de-Kostka

In Saint-Stanislas-de-Kostka, a central installation where exterior finishing matters just as much as winter performance

This installation of a MIDEA EVOX G3 central heat pump in Saint-Stanislas-de-Kostka illustrates an aspect of HVAC work that is immediately noticeable on a home: how the equipment, refrigerant lines, and electrical connections are integrated into the building envelope.

In the photo taken after our work, the MIDEA heat pump is installed on metal wall brackets, in front of the home's foundation and beneath a large red brick wall. On the left, a mature hedge limits the available space. Higher up, a window must remain fully functional. To the right of the unit are the technical connections and the electrical disconnect. Finally, the refrigerant lines run vertically up the building inside a finished line set cover, whose main section was selected in a brown tone that blends much better with the brick and the existing exterior elements than a highly visible long white line set cover.

This last detail is particularly interesting. In a central heat pump installation, the lines between the outdoor unit and the indoor unit can cover a considerable distance. When they must run up along a brick facade, their routing becomes an architectural element that remains permanently visible. We therefore have to solve two problems at once: properly protect the lines and prevent the mechanical equipment from visually dominating the facade.

Here, the vertical route is clean, straight, and organized. The technical installation becomes much less intrusive.

What we see in the photo and why these details matter

The EVOX G3 condenser is installed high enough that it does not rest directly on the ground. The metal brackets transfer the load to the foundation and provide clearance beneath the unit.

This choice is important in Saint-Stanislas-de-Kostka, where the equipment must withstand several seasons of snow, freezing temperatures, rain, and thawing.

A heat pump used for heating periodically produces water during its defrost cycles. If the unit is placed too close to the ground, ice can accumulate beneath the cabinet and eventually reduce the available clearance. The installation height is therefore a real part of preparing the system for Quebec winters.

We also note in the photo:

• the fully unobstructed large front fan;
• the unit positioned away from the window;
• the triangulated brackets attached to the foundation;
• the condenser feet and mounting points;
• the insulated refrigerant line on the right side;
• the outdoor electrical disconnect switch in the immediate vicinity;
• the protected vertical path of the lines into the building;
• the hedge retained to the left of the installation;
• the absence of piping left exposed along the entire height of the wall.

These are small details when examined separately. Together, however, they determine the final quality of a residential HVAC installation.

Why install the EVOX G3 above ground level

The MIDEA EVOX G3 is part of a family of Inverter central heat pumps designed for low-temperature heating.

According to the Midea documentation provided for this installation, the Extreme Heat range can continue operating down to -30 °C. The manufacturer also indicates a heating capacity of up to 100% at approximately -25 °C, with a COP of approximately 1.9 under the specified test conditions.

A machine intended to continue operating at these temperatures must be installed accordingly.

It would be inconsistent to select a heat pump capable of operating at -25 °C or -30 °C and then position it somewhere where the first significant snow accumulation blocks the heat exchanger or reduces its defrosting clearance.

That is why we consider the following from the outset:

height, airflow, defrost water, accessibility, and the likely accumulation of snow around the house.

A front discharge that changes how the outdoor unit is positioned

The EVOX G3 uses a different format from many conventional central condensers with vertical fans.

Here, the fan discharges air horizontally toward the front.

Midea pairs this horizontal discharge with a vertical heat exchanger and indicates that this architecture is intended to promote more uniform airflow through the heat exchanger. The manufacturer also specifies that this design improves heat-exchange performance as the temperature drops.

In the context of this home in Saint-Stanislas-de-Kostka, this allows us to position the unit against the foundation while directing its discharge toward the open space in front of it.

The front area must nevertheless remain clear. A hedge, fence, bench, snow accumulation, or any other obstacle placed too close to the fan can interfere with operation.

The hedge next to the heat pump: a detail to monitor over time

The photo shows dense vegetation to the left of the unit.

During installation, the clearances required by the manufacturer must obviously be respected. But responsibility does not end once the work is completed.

A shrub grows.

A hedge that perfectly respects the clearances at the time of installation may eventually grow closer to the coil, reduce airflow, or make servicing more difficult.

Our practical advice for this type of setup is therefore simple: periodically trim the vegetation around the condenser and maintain the required clearances.

You should not wait for the branches to touch the heat pump.

A well-protected vertical refrigerant line route

One of the most distinctive elements of this installation is the outdoor path of the lines.

The connection leaves the heat pump on its right side, then runs up the wall before joining the rest of the system. Instead of leaving a long section of insulated copper, wires, and drain exposed, the main route is placed inside a vertical protective line set cover.

The dark color of the upper section integrates much better with the brick wall than a contrasting white cover running the entire height.

On a residential project, this finish serves several purposes:

• protect the refrigerant lines from impacts and the elements;
• stabilize the path of the lines;
• reduce the insulation's exposure to the sun;
• visually group the different elements;
• make integration with the façade easier;
• avoid an installation that looks like it was improvised afterward.

For us, this kind of detail is part of HVAC work, just like evacuation and pressure checks.

Why we never choose an EVOX G3 solely according to the BTU rating listed on a quote

The name MIDEA EVOX G3 refers to a product line, not a single capacity.

Midea documentation lists several capacities ranging from approximately 18,000 to 54,000 BTU/h, with performance ratings reaching up to 19 SEER2, 12.5 EER2, and 10.8 HSPF2, depending on the selected combination.

The specifications table includes, among others, the following combinations:

• 18,000 BTU: MAUSE-H18B-2A + MO1HE-H18B-2A;
• 24,000 BTU: MAUSE-H24B-2A + MO1HE-H24B-2A;
• 30,000 BTU: MAUSE-H30B-2A + MO1HE-H30B-2A;
• 36,000 BTU: MAUSE-H36B-2A + MO1HE-H36B-2A;
• 48,000 BTU: MAUSE-H48B-2A + MO1HE-H48B-2A;
• 54,000 BTU: MAUSE-H60B-2A + MO1HE-H60B-2A.

The rating plate visible on the side of the condenser in the photo is not legible enough for us to state with certainty the exact capacity of this particular unit. We prefer to preserve this distinction rather than attribute an unconfirmed tonnage to the project.

SEER2 and HSPF2: efficiency varies by model

Not all EVOX G3 units have exactly the same efficiency.

In the documentation provided, the Extreme Heat configurations are listed as follows:

18,000 BTU: 19 SEER2, 12.5 EER2, 10.1 HSPF2

24,000 BTU: 18.6 SEER2, 12 EER2, 10 HSPF2

30,000 BTU: 17.2 SEER2, 12 EER2, 10.8 HSPF2

36,000 BTU: 17.7 SEER2, 12 EER2, 10.0 HSPF2

48,000 BTU: 17.5 SEER2, 12 EER2, 9.5 HSPF2

54,000 BTU: 17.5 SEER2, 12 EER2, 9.5 HSPF2.

These figures illustrate an important reality: the best choice for a home is not necessarily the machine with the greatest capacity.

Proper sizing begins with the building.

What we analyze before choosing the tonnage of a central heat pump

To size a central heat pump in Saint-Stanislas-de-Kostka, we must notably assess:

• the home's heat loss;
• the heated area and volume;
• the insulation level;
• the windows;
• air infiltration;
• the duct system configuration;
• the available airflow;
• the auxiliary heating capacity;
• the electrical supply;
• the behavior of the existing system.

The duct system deserves particular attention.

A heat pump can provide a great deal of heat, but that heat must then be transported efficiently to the rooms.

Computational Constant Airflow 2.0: useful in existing duct systems

The EVOX G3 uses Computational Constant Airflow 2.0 technology.

Midea indicates that the indoor fan can adjust its speed and output to better maintain the requested airflow when system pressure changes. The documentation illustrates conditions of up to 1.2 in. of water column static pressure and mentions up to 60 airflow customization levels.

This function can be particularly relevant when replacing equipment in an existing home.

The resistance of the ductwork can change depending on:

• the duct dimensions;
• the length of the ductwork;
• the elbows;
• the condition of the filters;
• the type of filtration;
• the grilles;
• the return air openings;
• the damper configuration.

The goal, however, is not to use a more sophisticated fan to hide a poor ductwork system.

If the ductwork has a major restriction, we prefer to identify the problem and correct it whenever possible.

From the outdoor unit to the air handler: why the EVOX G3 works as a complete system

An indoor unit designed for renovation projects

The EVOX G3 is not limited to the gray condenser visible in the photo.

Inside, the system uses an air handler that must be integrated into the home's ductwork.

Midea developed a modular cabinet that can be installed in six orientations, including vertically, horizontally or in certain “low-boy” configurations for spaces with limited height.

This flexibility can make a big difference in a basement.

We frequently work in homes where the old unit has been surrounded over the years by finished walls, plumbing, a water heater or other equipment.

Being able to adapt the position of the indoor unit makes certain conversions easier without completely rebuilding the mechanical room.

A format designed to fit in the space occupied by many older furnaces

Midea specifies cabinet widths of approximately 14.5 to 21.5 inches, depending on capacity. The documentation also mentions a multivoltage indoor power supply of 115 V or 208/230 V.

This can facilitate the replacement of certain older central furnaces.

But “ease of replacement” never means “automatic installation.”

We always check the sheet metal transitions, return air, supply plenum, clearances, wiring and available capacity.

Up to 25 kW of auxiliary heating, but only when properly sized

Midea documentation provides for 10 kW, 15 kW and up to 25 kW auxiliary electric heater kits, with operation in multiple stages.

This function is important in Quebec.

Even with a high-performance heat pump in very cold weather, auxiliary heating may be used:

• under extreme conditions;
• during certain defrost cycles;
• to accelerate a significant temperature rise;
• as backup when demand exceeds the available capacity.

However, an electric element is not free from an energy standpoint.

We therefore avoid simply selecting « the biggest possible ».

The capacity must match the home and the electrical capacity actually available.

The choice between 485 communication and a 24 V thermostat

The EVOX G3 also offers some flexibility in terms of controls.

The documentation mentions compatibility with 485 communication as well as 24 V controls, with the possibility of integrating certain third-party thermostats in the specified configurations.

In a renovation project, this flexibility is valuable.

We can choose the appropriate strategy based on the existing wiring, the desired functions, and the equipment combination used.

With the Midea communicating system and the SmartHome app, the documentation also indicates programming, self-diagnostic, consumption monitoring, and remote update functions.

Filtration up to MERV 13, depending on the selected module

A central system can filter the air circulating throughout the home.

Midea provides a module compatible with 1-, 2-, or 4-inch filters, including MERV 13 in the configurations described.

MERV 13 can capture more fine particles than a very basic filter.

However, we must confirm that the ductwork can handle the additional resistance.

The right approach is not « more filtration at all costs », but the best balance between filtration and airflow.

R-454B: what the new generation changes for installation

Midea uses R-454B in the range described.

The brochure identifies it as a refrigerant A2L with a global warming potential, or GWP, of 466.

For the homeowner, the refrigerant remains essentially invisible.

For our team, however, it requires an adapted work method: compatible tools, handling procedures, circuit preparation, and commissioning in accordance with the requirements for this type of equipment.

Replacing an old R-410A heat pump with a modern unit must therefore never be treated as a simple box swap.

Eligibility for financial incentives: the exact combination number remains essential

Midea documentation indicates that the featured range exceeds the ENERGY STAR Most Efficient specifications mentioned by the manufacturer.

For a homeowner who wants to benefit from financial assistance such as LogisVert, this efficiency is appealing, but it is not enough to determine a precise amount.

At AirGreen, we always verify:

• the exact outdoor model;
• the exact indoor model;
• the certified combination;
• the applicable AHRI number;
• the installation date;
• the program criteria at the time of the work.

The name « MIDEA EVOX G3 » does not replace this verification.

The mistakes this installation helps avoid

Leaving the lines exposed across an entire façade

When the refrigerant line run is long and vertical, proper protection improves both durability and the final appearance.

Placing the heat pump directly against vegetation

The hedge visible on the left must remain trimmed to preserve airflow and service access.

Installing the unit too low

A heat pump designed to continue heating when it snows must maintain sufficient clearance from the ground and winter snow accumulation.

Neglecting access to the electrical disconnect

The disconnect device visible to the right of the unit must remain accessible for servicing.

Choosing the tonnage before checking the ductwork

A central system must be able to move the volume of air required by the selected capacity.

An installation that integrates into the home rather than simply being added to it

This Saint-Stanislas-de-Kostka project is particularly interesting because it shows how several relatively discreet decisions can completely change the result.

The heat pump is aligned with the foundation. It is elevated. The window remains unobstructed. The hedge is preserved. The connections are arranged on one side only. The disconnect switch is accessible. Above all, the long run to the upper part of the house is protected by a line set cover whose colour greatly limits the contrast with the brick wall.

These are the details we strive to master in every central heat pump installation.

The MIDEA EVOX G3 offers interesting technical features: Inverter technology, operation in very cold weather, R-454B, a modular indoor unit, advanced airflow management and various control options.

At AirGreen, our role is to turn these characteristics into a system that is truly suited to the building.

This is the same method we apply in our HVAC projects in Montreal, Laval, Longueuil, on the South Shore, on the North Shore and in municipalities such as Saint-Stanislas-de-Kostka: first understand the home, then install the equipment so that it is efficient, accessible, neat and durable.