Installation of a MIDEA EVOX G3 central heat pump in Très-Saint-Rédempteur, Montérégie

A central installation adapted to Quebec’s climate and the real-world constraints of an existing home

In Très-Saint-Rédempteur, we completed this MIDEA EVOX G3 central heat pump installation at a residence where several outdoor elements had to be considered simultaneously: brick wall, foundation, mature vegetation, downspout, existing electrical supply, and available space around the equipment.

The site photograph shows an installation that appears relatively simple once completed: a MIDEA outdoor unit properly aligned with the facade, installed on elevated wall brackets, with its electrical disconnect placed nearby. However, this type of result requires precise planning.

The heat pump’s placement directly affects its operation during the winter, access for HVAC maintenance, airflow quality, and the ease of future service work. For this installation in Très-Saint-Rédempteur, we therefore worked as much on integrating the unit with the building as on connecting the system itself.

An outdoor location where every existing element mattered

To the left of the outdoor unit, there is a mature conifer hedge. On the right is the electrical disconnect, while a downspout runs vertically down the facade above the installation.

This type of environment requires a much more thoughtful approach than simply “finding a place” for the heat pump.

We need to maintain several clearances:

• in front of the large front fan;
• around the coil;
• under the heat pump for defrosting;
• near the service panel;
• around the electrical disconnect;
• between the unit and the vegetation.

The hedge shown in the photo is one feature that will need to be monitored over the years. Vegetation that appears sufficiently far away at the time of installation can gradually move closer to the coil.

We therefore recommend keeping the branches trimmed to preserve airflow and access to the side of the unit.

Why we raised the MIDEA EVOX G3

The heat pump is installed on two metal brackets secured to the foundation, rather than directly on a ground-level slab.

For a central heat pump used during the winter, this additional height is particularly important.

In heating mode, the outdoor heat exchanger can accumulate frost. The system then periodically runs a defrost cycle. The resulting water must be able to drain beneath the unit without quickly forming a mass of ice directly against the chassis.

The elevation also helps reduce the risk of snow accumulated around the house quickly reaching the lower part of the unit.

On a job site in Très-Saint-Rédempteur, where the system must operate through real periods of Quebec cold, we want to keep this space beneath the machine from day one.

A horizontal-discharge outdoor unit

The large front fan is one of the most visible elements of the EVOX G3.

Midea describes this platform as using a horizontal discharge design, combined with a vertical heat exchanger. According to the documentation, this architecture is intended to provide more uniform airflow across the entire heat exchanger.

This geometry also makes it possible to maintain a relatively shallow profile against the building.

In this installation, the fan is directed toward an open area. No secondary wall or decorative screen is immediately in front of the grille.

This is important because a horizontal air discharge needs space to prevent the discharged air from returning directly toward the heat exchanger.

A central heat pump designed to operate down to -30 °C

The MIDEA EVOX G3 Extreme Heat was developed specifically for cold climates.

The documentation provided by Midea indicates continuous operation down to -30 °C. It also mentions up to 100% heating capacity at -25 °C, with a COP of up to 1.9 under the reference conditions presented by the manufacturer.

For an installation in Très-Saint-Rédempteur, this operating range is particularly relevant.

We do not choose a central heat pump solely based on its performance when temperatures are mild. We are mainly interested in what it can still deliver when temperatures become truly wintry.

The brochure explains that, when the system operates in extremely cold conditions, the compressor uses an intermediate-temperature vapor supply to increase the total amount of compressed refrigerant and support heating.

Operation down to -30 °C does not mean that supplemental heating is completely unnecessary

However, two concepts must be distinguished.

The first is the minimum operating temperature of the heat pump.

The second is the amount of heat required to maintain a given home at the desired temperature.

A very well-insulated home may require much less capacity than an older house with several large windows, air leaks, or high ceilings.

We therefore never consider the figure of -30 °C a guarantee that the heat pump will cover all the building's heat losses on its own in every situation.

The right approach is to size the entire system.

The EVOX G3 range covers several different capacities

The EVOX G3 is not a single heat pump with one fixed capacity.

The documentation presents a range of systems from 18,000 to 54,000 BTU/h in cooling, with different performance levels depending on the indoor and outdoor unit combinations.

Midea announces values for this family that can reach:

• 19 SEER2;
• 12.5 EER2;
• 10.8 HSPF2;
• COP of 2.14 at 5 °F, or approximately -15 °C.

The brochure's technical table shows configurations of 18,000, 24,000, 30,000, 36,000, 48,000, and 54,000 BTU/h, among others.

The photo of our project in Très-Saint-Rédempteur does not allow us to reliably read the unit's complete model number. We therefore do not artificially assign it a specific capacity.

To confirm the exact capacity of an installation, we always use the outdoor unit model and the indoor unit model.

Why sizing remains essential even with an inverter heat pump

An inverter central heat pump offers more modulation than a traditional fixed-capacity system.

That does not mean, however, that sizing becomes secondary.

We check, in particular:

• the building's heating load;
• the area actually served;
• the insulation level;
• the windows;
• the airtightness;
• the orientation of the house;
• the ductwork capacity;
• the available electrical capacity;
• the potential need for supplemental heating.

A machine that is far too large may operate in a less favorable range for much of the year.

Conversely, a unit that is too small may require more supplemental heating during periods of extreme cold.

The goal, therefore, is to choose a MIDEA central heat pump that truly matches the building.

Behind the outdoor heat pump: the ductwork, indoor unit, and settings that determine actual comfort

A platform designed to facilitate central system replacements

The EVOX G3 was designed with several useful features when replacing an old furnace or an older central heat pump.

Midea indicates that the indoor unit can accommodate 115 V and 208/230 V power supplies depending on the configuration. The documentation also mentions cabinet widths of 14.5 to 21.5 inches, intended to correspond more easily to the dimensions of many existing furnaces.

This compatibility can limit certain major modifications in a mechanical room.

However, this does not mean that no adaptations are required.

We must always check:

• the return air;
• duct transitions;
• the plenum;
• condensate drainage;
• access to the filter;
• the power supply;
• service clearances.

Six possible configurations for the air handler

Midea also presents a modular interior design that allows six installation orientations.

According to the documentation, the unit can be configured, among other ways, as follows:

• upward discharge;
• downward discharge;
• right horizontal;
• left horizontal;
• “low-boy” configurations suited to tight spaces.

The modular design is also intended to facilitate moving the unit into difficult-to-access areas such as certain basements or attics.

For a renovation, this flexibility can genuinely simplify the work.

Airflow: one of the most underestimated elements of a central system installation

A central heat pump may deliver excellent performance on paper and still produce mediocre results if air does not circulate properly through the ductwork.

Midea equips the EVOX G3 with its Computational Constant Airflow 2.0 technology.

The documentation shows adaptability up to 1.2 in. of water column static pressure in the illustrated examples, as well as up to 60 air-flow adjustment levels.

The fan can therefore adjust its operation to different system conditions.

However, this capacity remains an adjustment tool.

It does not replace properly sizing the ductwork.

Poor return airflow does not become acceptable just because the fan is more advanced

An ECM motor can increase its effort to maintain airflow.

But if the return is too small, if the filter is too restrictive, or if several ducts are severely restricted, the underlying cause must be corrected.

At AirGreen, we therefore seek to obtain a system that operates with reasonable static pressure, rather than forcing the fan to compensate constantly for an inadequate duct network.

MERV 13 filtration available in several sizes

Midea documentation indicates compatibility with 1-, 2-, and 4-inch MERV 13 filters in the filtration module provided for this purpose.

This type of filtration can capture more dust, pollen, particles, and pet dander.

For the homeowner, this can be an appealing improvement to the home's air filtration.

But we always consider the filter size and system airflow simultaneously.

A small, highly restrictive filter can become a bottleneck.

The objective is therefore to combine filtration quality and low air resistance.

Auxiliary heating can reach 25 kW depending on the configuration

The brochure also provides for multistage auxiliary electric heating kits that can reach 25 kW, depending on the selected configuration.

Auxiliary heating remains relevant in our climate.

It can come into operation when the home's heat loss temporarily exceeds the available capacity of the heat pump.

It can also serve as backup under certain extreme conditions.

However, we seek to avoid activating it unnecessarily early.

A good control strategy should allow the heat pump to do as much of the work as reasonably possible before adding electric resistance.

Control options suited to renovations

Midea indicates that the EVOX G3 can operate with several communication strategies.

The documentation notably mentions:

• the protocol 485;
• 24 V thermostats;
• certain wireless communication options between system components.

The manufacturer also presents its communicating thermostat and the SmartHome app, which can be used to manage schedules, comfort, certain consumption information, and diagnostic functions.

This flexibility is useful when old thermostat wiring already exists in the house and replacing it would be complicated.

R-454B at the heart of this new generation of systems

The MIDEA EVOX G3 uses R-454B refrigerant.

Midea indicates a global warming potential of 466 for this A2L refrigerant.

For an HVAC installation, this change has practical consequences.

Technicians must use methods and equipment suited to R-454B systems during:

• refrigerant connection;
• leak testing;
• vacuuming;
• commissioning;
• future service work.

This is therefore not merely an environmental feature mentioned in a brochure: it directly influences how the installation must be carried out.

A detail visible in the photo: the electrical disconnect is accessible

To the right of the outdoor unit, we can clearly see the DiversiTech electrical disconnect enclosure.

Its location near the heat pump allows for an easily identifiable local disconnect.

For maintenance and diagnostics, this accessibility is essential.

We want a technician to be able to isolate the equipment without having to look for a hidden device behind a hedge or in an inaccessible area.

The electrical conduit also follows a neat path along the wall.

The pipe visible beneath the unit highlights the importance of drainage

Under the heat pump, we can also see a small pipe descending toward the ground.

On a central installation, we must manage several potential sources of water: condensate, outdoor defrost water and, depending on the configuration, drainage from the indoor unit.

The water must be directed so that it does not create a problem elsewhere.

Drainage often seems secondary when a heat pump is sold, but it quickly becomes important when a system operates day after day.

Vegetation must remain under control

The hedge to the left of the heat pump is probably the most important visible outdoor maintenance point in this photo.

We recommend trimming it periodically.

An outdoor coil that begins to be covered or surrounded by branches can:

• receive less air;
• accumulate more debris;
• become more difficult to clean;
• make access more difficult during a repair.

It is better to plan for this growth from the start.

What we avoid on an installation like the one in Très-Saint-Rédempteur

Installing the heat pump too low

This reduces snow clearance and makes it easier for ice to form beneath the unit.

Enclosing the unit between vegetation and a decorative screen

The fan needs an unobstructed air discharge.

Neglecting the ductwork

An excellent outdoor heat pump will never fully compensate for an undersized return or poorly designed air distribution.

Choosing a tonnage simply because the old unit had the same capacity

The home’s needs must be assessed.

Assuming that a maximum value for the range applies automatically

Values such as 19 SEER2 or 10.8 HSPF2 are range maximums, not figures applicable to all EVOX G3 combinations.

What about eligibility for financial assistance?

The Midea brochure indicates that the range exceeds certain ENERGY STAR specifications in the context presented by the manufacturer.

However, the document provided alone does not make it possible to confirm this Très-Saint-Rédempteur installation’s exact eligibility for a Quebec subsidy.

To do this, it is necessary to know the exact combination of the indoor and outdoor units, as well as the certification applicable to the program concerned.

At AirGreen, we therefore prefer to verify model numbers and certified references before announcing a financial assistance amount.

A discreet installation that conceals a great deal of technical work

At first glance, this MIDEA EVOX G3 installed in Très-Saint-Rédempteur seems to be simply mounted against the foundation.

But the quality of a central installation is measured above all by the many elements that are not immediately noticeable.

The heat pump is elevated to better handle winter conditions. Its front fan remains unobstructed. The electrical disconnect is accessible. Vegetation can be maintained without moving the unit. The indoor duct network must be adapted to the required airflow. The air handler, filtration, thermostat, and auxiliary heating must all be adjusted as a single system.

The EVOX G3 offers an interesting platform thanks to its advertised operation down to -30 °C, inverter technology, R-454B refrigerant, modular indoor unit, and advanced airflow control functions.

Our work at AirGreen consists of turning these technical features into an installation that suits the actual residence.

It is this same approach that we apply to our MIDEA central heat pump installations in Très-Saint-Rédempteur, Rigaud, Vaudreuil-Dorion, Hudson, Montréal, Laval, Longueuil, on the South Shore and on the North Shore: proper sizing, accessible installation, attention to Quebec winters, and commissioning of the complete system.