Installation of a MIDEA EVOX G3 central heat pump in Sainte-Clotilde, Montérégie, on the South Shore

A raised MIDEA EVOX G3 in a confined yard: a central installation designed for snow, defrosting and service access

At Sainte-Clotilde, installing this MIDEA EVOX G3 central heat pump required us to look well beyond the simple positioning of the outdoor unit. The job-site photo shows a relatively compact space surrounded by masonry walls, with a concrete surface on the ground and other equipment nearby. In this context, every centimetre counts: airflow in front of the condenser must be preserved, practical access for maintenance must be maintained, and above all, we must consider what will happen when snow and freezing temperatures become part of the surroundings.

We therefore installed the outdoor unit on a raised four-legged metal support, rather than directly on the concrete. The grey Midea condenser is thus well clear of the ground, with significant space beneath the unit. This configuration is particularly relevant for a central heat pump used as a heating source during Quebec winters.

The photographed scene is also interesting because it represents a common situation on existing properties on the South Shore: we do not always work in a large, completely open yard. Sometimes a new machine must be integrated between a wall, a window, electrical conduits, an existing structure and other outdoor equipment. A successful installation must therefore balance performance, clearances, maintenance and normal use of the property.

The detail that immediately draws attention: the heat pump does not rest on the ground

In the photo, the MIDEA EVOX G3 is supported by an independent metal structure. The support’s four feet rest on the existing surface, and the condenser is several dozen centimetres above the concrete.

This height is not merely aesthetic.

When a central heat pump operates in heating mode, its outdoor unit must continue exchanging heat with the air even when the temperature drops sharply. The system must also manage the necessary defrosting periods when frost forms on the coil.

In a climate like Sainte-Clotilde’s, we therefore need to consider several factors from the moment of installation:

• snow accumulation around the unit;
• the space required beneath the unit;
• drainage of the water produced during defrosting;
• the possibility of this water freezing again;
• access to the service panel;
• air circulation in front of the fan's large grille;
• the clearance around the condenser.

A unit installed too close to the ground can become much more vulnerable to winter conditions. The support visible here gives us a significantly greater margin.

An independent support rather than arms anchored directly into the masonry

For some projects, we can use wall-mounted supports. Here, the photo shows more of a freestanding structure, with its own feet.

This difference is interesting.

An independent support notably prevents the entire weight of the unit and its vibrations from being transferred to the exterior wall. Depending on the building configuration, the condition of the masonry, and the site constraints, this solution may be much more logical.

The choice of support must always be based on the actual site. We never consider one mounting method to be automatically better for all properties.

In Montreal, Laval, Longueuil, on the North Shore or the South Shore, we encounter brick, stone, and concrete homes, buildings with light cladding, as well as buildings where the available space around the foundation varies considerably. Our objective remains the same: to provide a stable base and keep the heat pump in good operating conditions.

A condenser installed in an area where air discharge must remain unobstructed

The large circular grille visible at the front of the EVOX G3 is the outdoor fan. On this product line, Midea uses a horizontal discharge design combined with a vertical heat exchanger. The documentation presents this architecture as a way to achieve more uniform air exchange and better heat exchanger efficiency as temperatures drop.

This explains why we place so much importance on the space immediately in front of the unit.

In this Sainte-Clotilde yard, the condenser is positioned so that its front is not pressed against a solid obstacle. Even if the surrounding space is limited, the goal is not to turn the air outlet into a confined area.

A heat pump may be perfectly sized on paper, but if its outdoor environment promotes poor air circulation, its actual operating conditions will no longer be those anticipated by the manufacturer.

The presence of another outdoor unit also requires consideration of clearances

To the left of the Midea, we see another covered piece of equipment. Without more information about this device, we cannot determine its exact function from the photo alone.

What we can nevertheless observe is that the outdoor space had to be shared.

In this kind of situation, we carefully inspect the location to ensure that one unit does not obstruct the other. Service access is also important: a technician must be able to remove the heat pump panels, inspect the connections, and work around the unit without having to dismantle permanent elements of the property.

This is an aspect that is often underestimated when buying a heat pump. However, an installation that facilitates HVAC service and heat pump maintenance remains much more practical throughout the equipment's service life.

An ÉnerGuide label visible on the unit

The photo also clearly shows a yellow ÉnerGuide label affixed to the condenser's front panel.

We cannot reliably read the precise data on this label in the supplied image, so we avoid assigning this installation an efficiency rating that has not been confirmed by the exact model.

This caution is important with a range like the MIDEA EVOX G3, since it comes in several capacities and several indoor-outdoor combinations.

The figure that appears in an advertisement or in the maximum advertised for a series does not necessarily correspond to every installed combination.

EVOX G3: continuous operation down to -30 °C according to Midea

The most relevant feature of this platform for a Quebec homeowner remains its low-temperature heating capacity.

Midea states that the EVOX G3 Extreme Heat offers continuous operation down to -30 °C. The documentation also shows, for a three-ton system used in the cited tests, up to 100% heating capacity at -25 °C with a COP of approximately 1.9.

The manufacturer also explains that, under extreme cold conditions, its compressor technology uses an intermediate-temperature vapor supply to increase the amount of compressed refrigerant and enhance heating performance.

For a property in Sainte-Clotilde, this type of specification is much more useful than the nominal cooling capacity alone.

A central heat pump must be evaluated as a four-season system. In Quebec, it is not enough for it to cool the house effectively in July: we must also analyze what it can provide when temperatures drop below freezing for several days.

A range covering multiple central system capacities

The EVOX G3 documentation presents cooling capacities ranging from 18,000 to 54,000 BTU/h, with several combinations of indoor and outdoor units.

The range’s technical table includes the following capacities:

• 18,000 BTU/h;
• 24,000 BTU/h;
• 30,000 BTU/h;
• 36,000 BTU/h;
• 48,000 BTU/h;
• 54,000 BTU/h.

Depending on the combination, the published values reach up to 19 SEER2, 12.5 EER2, and 10.8 HSPF2.

However, the photo does not make it possible to confirm the exact tonnage of this Sainte-Clotilde installation with certainty. We therefore do not claim that it is a 2.5-ton, 3-ton, or other capacity simply by looking at the cabinet size.

To properly identify an installation, we rely on the model number, the nameplate, and the corresponding AHRI combination.

Why tonnage should never be chosen simply by looking at the old machine

When a homeowner replaces an old central heat pump, it may be tempting to order exactly the same number of tons.

This is not always the best method.

A home may have been renovated since the original system was installed. The insulation may have changed, windows may have been replaced, the basement may have been finished, or the duct network may have been modified.

Before determining the capacity of a MIDEA EVOX G3, we therefore consider the entire building:

• room dimensions and layout;
• fenestration;
• insulation level;
• heat losses;
• duct network;
• required airflow;
• return air;
• electrical system capacity;
• auxiliary heat;
• low-temperature operating conditions.

A central system cannot be evaluated solely by the size of the outdoor cabinet.

The EVOX G3 is also an indoor system modernization platform, not just an outdoor heat pump

The unit visible in the yard is only half of the system. A MIDEA EVOX G3 central heat pump works with an indoor unit and a duct network that distributes conditioned air throughout the property.

It is precisely this indoor component where the G3 generation brings several interesting features for replacing existing systems.

An air handler designed for multiple installation positions

Midea introduces the EVOX G3 indoor unit with a Block N Lock modular design, allowing multiple orientations.

The brochure indicates six possibilities, including upflow, downflow, horizontal right, horizontal left, as well as compact “low-boy” configurations.

This can be very useful in homes where the mechanical room offers little clearance.

We regularly encounter units installed in Greater Montreal and the Montérégie region in:

• a low basement;
• a very narrow mechanical room;
• a space under a staircase;
• an attic;
• a utility room with a structure that prevents a standard orientation.

The ability to reconfigure the indoor unit provides more options for properly connecting the existing ducts.

Dimensions designed to facilitate certain furnace replacements

The documentation also presents the EVOX G3 as a solution that can more easily replace certain older furnaces.

Midea lists cabinet widths of approximately 14.5 to 21.5 inches, corresponding to sizes commonly found on furnaces with similar capacities.

This does not mean that a new unit will automatically connect to any existing system.

In the field, we must always inspect:

• the supply plenum;
• the return air;
• metal transitions;
• filtration;
• available height;
• drain access;
• the auxiliary heating location;
• the clearances required for service.

But when a manufacturer designs its cabinet around dimensions compatible with the existing equipment, it can simplify an upgrade and reduce certain unnecessary modifications.

Automatic adaptation to airflow and duct pressure

An important feature of the EVOX G3 is found in the Computational Constant Airflow 2.0 technology.

Midea indicates that the system can adjust motor output and fan speed to better adapt to duct system conditions and variations associated with filtration. The documentation specifies a capacity of up to 1.2 in. of static pressure, with airflow that can be customized across up to 60 levels.

For us, this feature is particularly relevant in a renovation.

An existing duct system is not always ideal. Some systems have been modified several times over the years. Technology capable of better compensating for certain pressure variations offers greater flexibility during commissioning.

However, this does not mean that a poor duct system can be ignored. A duct that is too small, heavily obstructed, or poorly distributed must still be assessed as such.

MERV 13 filters up to four inches thick

The EVOX G3 documentation also specifies a module compatible with 1-, 2-, or 4-inch MERV 13 filters. Midea indicates that this filtration can capture more dust, pollen, particles, as well as pet hair and dander, while helping keep the indoor coil cleaner.

In a central installation, we always pay attention to the trade-off between filtration and airflow.

A more efficient filter must be integrated into the system while taking its air resistance into account. Filtration selected solely according to its rating, without considering the HVAC network, can unnecessarily increase static pressure.

485 communication, 24 V control, and compatible thermostat

The EVOX G3 line also offers several control strategies.

The brochure mentions compatibility with 485 communication as well as 24 V control and third-party thermostats. The system is designed to automatically identify the control mode being used.

Midea also provides Sub-1 GHz wireless communication between certain system components, allowing compatible configurations to reduce the need for new communication lines between the indoor unit, heat pump, and thermostat.

For a completed home, this can be very useful: running a new control cable can sometimes require a complex route through several floors.

Auxiliary heating up to 25 kW, depending on the configuration

In a Quebec central system, auxiliary heating deserves particular attention.

Midea offers three-stage auxiliary electric heating kits for the EVOX G3, up to 25 kW, with adjustment based on temperature changes.

The choice of this element must never be made independently of the rest of the property.

We must check, among other things:

• the electrical panel’s capacity;
• the power actually required;
• the wire gauge;
• the auxiliary heating control strategy;
• the heat pump’s own capacity at low temperatures.

A larger electrical element is not automatically a better solution.

R-454B: the new generation of refrigerant used by EVOX G3

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

Midea states that this refrigerant has a global warming potential, or GWP, of 466, and specifies that it selected it for its affected EVOX central product line.

For an HVAC company, this change is not merely a marketing detail.

The refrigerant used affects handling procedures, tools, commissioning, and the precautions we must take during installation. A new central heat pump must therefore be installed according to the specific requirements of its generation and refrigerant.

What we check before leaving a central system installation like the one in Sainte-Clotilde

Once the outdoor unit is secured and the connections are complete, the work is not finished yet.

A complete commissioning must allow the system’s performance to be verified under several conditions.

We check, among other things:

• outdoor unit operation;
• indoor unit response;
• thermostat control;
• air circulation;
• relevant pressures and temperatures;
• heating;
• air conditioning;
• drainage;
• the response of the auxiliary heating when present;
• abnormal noises or vibrations;
• the accessibility of the main components for servicing.

In the photographed installation, we also check the stability of the outdoor support and the space left beneath the unit.

These checks are what transform a physically completed installation into a truly operational HVAC system.

The mistakes we want to avoid with a central heat pump in Quebec

An installation like the one in Sainte-Clotilde also provides an opportunity to highlight several common mistakes:

• installing the condenser directly at the level where snow accumulates;
• neglecting the drainage of defrost water;
• enclosing the fan face in an overly confined space;
• selecting the tonnage solely based on the old unit;
• installing auxiliary heating without checking the electrical panel;
• neglecting the static pressure of the ductwork;
• using filtration that is too restrictive without measuring its impact;
• advertising a maximum SEER2 or HSPF2 as if it automatically applied to all models;
• forgetting to allow the necessary access for HVAC maintenance.

At AirGreen, we consider all these elements to be an integral part of the project.

A discreet but technically well-planned installation

Visually, the result is simple: a dark gray Midea unit, perfectly straight, on a metal support against the property's facade.

But behind this apparent simplicity are several important decisions.

We had to work with the available space, the existing concrete, the masonry walls, the other equipment, the fan clearance, and the realities of winter. We were also dealing with a central platform whose performance depends on the proper sizing of the outdoor unit, indoor unit, ductwork, and auxiliary heating.

This comprehensive approach is what we apply to our central heat pump installations in Sainte-Clotilde, Montreal, Laval, Longueuil, the North Shore, and the South Shore.

The MIDEA EVOX G3 offers several interesting features: very-low-temperature heating, Inverter technology, horizontal-discharge condenser design, modular indoor unit, advanced airflow adjustment, MERV 13 filtration, and control flexibility.

But the performance figures listed in a brochure only take on their true value when the system is installed correctly.

At AirGreen, we therefore place just as much importance on the support shown in the photo as on the much less visible components located in the mechanical room. A central heat pump operates as a system, and it is this system that we seek to optimize in every project.