Installation of a MIDEA EVOX G3 central heat pump in Huntingdon, Montérégie

In Huntingdon, an EVOX G3 installed in a narrow exterior passage where the choice of location made all the difference

For this MIDEA EVOX G3 central heat pump in Huntingdon installation, the difficulty of the project did not come solely from the refrigerant connection or the integration with the home's ductwork. The photograph immediately shows the main constraint: the outdoor unit had to be placed in a relatively narrow side passage, between two sections of the building, near a window and with little floor space available.

In this type of configuration, a few centimetres can change the entire installation strategy.

We therefore installed the outdoor unit on a raised metal structure, rather than placing it directly at ground level. The fan side remains oriented toward the open space of the passage, while the unit is positioned compactly against the building. This solution keeps the condenser out of the area most exposed to snow, water, and debris accumulation while limiting its footprint.

The result is particularly representative of our approach at AirGreen: an HVAC installation must be designed around the actual house, not just the dimensions listed in a brochure.

A central heat pump in a space where airflow had to be considered from the outset

The MIDEA outdoor unit visible in the photo uses a horizontal discharge fan. In an unobstructed space, positioning is relatively simple. In an exterior corridor like this one, however, the surfaces surrounding the machine must be analyzed.

On the right, we have the exterior siding of the house. On the left, a section of masonry forms another vertical plane. There is also a window behind and above the unit. The condenser therefore had to be positioned to preserve the required clearances, allow for servicing, and above all prevent the air discharged by the fan from immediately recirculating toward the coil.

This is precisely why a location that seems “perfect” because it hides a heat pump well is not always technically a good location.

A condenser needs air.

If it is enclosed between walls that are too close together, beneath a deck that is too low, or behind an almost closed fence, its operation may be impaired. On this Huntingdon project, orienting the large ventilated face toward the exterior passage is therefore a central element of the installation.

Elevating the condenser: a very important detail in Huntingdon

The support visible beneath the heat pump plays a much more important role than simply providing mechanical support.

During the winter, a central heat pump continues to operate while snow can accumulate along the foundation. During its defrost cycles, the outdoor unit also produces water. If the condenser is installed too low, this water can freeze around its base and contribute to the formation of an ice mass.

On this project, the unit is clearly kept above ground level.

This additional height helps better protect the lower part of the machine and preserve more space for drainage beneath the unit. In a relatively narrow passage like the one at this home, it also keeps the ground around the condenser more clear.

However, the elevated installation must remain stable. A central heat pump contains a compressor and a large fan, so its support must hold the unit properly while limiting vibrations.

Why the MIDEA EVOX G3 is particularly interesting for heating in cold climates

In Huntingdon, winter performance is not a secondary consideration. It is a fundamental part of choosing a heat pump.

The MIDEA technical documentation provided with this project presents the EVOX G3 as an Inverter central system designed for cold climates. The range covers capacities from 18,000 to 54,000 BTU/h and can achieve, depending on the exact equipment combination, 19 SEER2, 12.5 EER2, 10.8 HSPF2, and a COP of 2.14 at 5 °F.

An even more relevant point for Quebec is the heating range.

MIDEA announces continuous operation down to -30 °C. The documentation also presents performance of up to 100% of heating capacity at -25 °C, with a COP of approximately 1.9 under the test conditions cited by the manufacturer.

This does not mean that every home will maintain exactly the same consumption or that every EVOX G3 capacity will deliver exactly the same results. Performance depends on the indoor-outdoor pairing, outdoor temperature, airflow, ductwork, and the building’s actual load.

But this demonstrates why this platform deserves consideration for a central heat pump in Quebec.

M-Powevi technology and maintaining capacity as the temperature drops

MIDEA documentation also describes a compressor technology called M-Powevi.

In extreme cold conditions, the system uses intermediate-temperature vapor injection to increase the amount of compressed refrigerant and support heating performance. MIDEA combines this design with a high-efficiency compressor motor and optimized discharge-circuit design.

For the homeowner, the benefit is very practical.

A heat pump should not simply perform excellently at +8 °C and then quickly lose capacity when the home actually begins to demand substantial heating. We want a machine whose low-temperature performance matches the conditions encountered in Huntingdon and Montérégie.

The exact installed capacity must not be guessed from the photograph

The photo clearly identifies the MIDEA brand and the outdoor design of the EVOX G3 lineup. However, it does not allow the complete model number to be read reliably enough.

We therefore will not arbitrarily assign a capacity of 30,000, 36,000 or 48,000 BTU to this installation.

This is an important distinction.

The EVOX G3 lineup includes several sizes, and the performance ratings are not identical for each one. MIDEA’s performance table, for example, lists combinations of 18,000, 24,000, 30,000, 36,000, 48,000 and 54,000 BTU/h in cooling, with SEER2 and HSPF2 values that vary by model.

A professional installation therefore relies on the model numbers actually installed and the home’s heating load, not on the apparent size of the condenser.

A central heat pump must also be matched to the existing ductwork

The outdoor unit is only half of the installation.

Inside, the EVOX G3 works with an air handler that distributes heating and cooling throughout the home through the ductwork.

This is where another challenge arises: airflow.

An existing home may have ductwork sized for an older system, a relatively restrictive return-air path, several elbows, different registers, or a filter adding extra resistance.

In this generation, MIDEA uses its Computational Constant Airflow 2.0 system, designed to allow the indoor fan to adjust its output to the ductwork conditions. The manufacturer indicates a capacity of up to 1.2 in. water column of static pressure under the conditions presented and offers up to 60 airflow adjustment levels.

This feature is particularly useful in a replacement project, but it does not replace a properly designed duct network.

If a return air opening is much too small or a duct is almost blocked, electronics cannot physically eliminate that restriction. We must always check the existing ductwork before configuring the new heat pump.

From the outdoor unit to the complete system: the checks that make the difference on an EVOX G3

A modular indoor unit that makes renovations easier

The MIDEA EVOX G3 was also designed with existing central system replacements in mind.

Its air handler uses a Block N Lock modular design and can be installed in several orientations. MIDEA documentation presents six possible configurations, including upflow vertical, downflow vertical, left horizontal, right horizontal and various low-height arrangements.

This may seem secondary until the equipment has to be taken down to a basement via a narrow staircase.

In many homes in Montreal, Laval, Longueuil, the North Shore and the South Shore, we encounter exactly this situation: the mechanical room has enough space, but the route for getting the appliance there is much more limited.

A modular design gives the installer more options.

A design intended to replace certain existing furnaces

MIDEA also indicates indoor unit widths ranging approximately from 14.5 to 21.5 inches, dimensions similar to those of several residential furnaces. The range also supports 115 V or 208/230 V indoor power supplies depending on the configuration.

When replacing a central system, every inch counts.

An appliance that is too wide may require completely modifying the return air or plenum. An appliance that better matches the existing mechanical space can allow for a much cleaner transition to the home's ductwork.

Nevertheless, we must always redo the transitions when necessary to ensure uniform airflow.

Auxiliary heating should complement the heat pump, not work unnecessarily in its place

The EVOX G3 range allows electric auxiliary heating to be used in several stages. MIDEA offers kits of up to 25 kW, with activation and adjustment based on temperature changes.

In a Quebec installation, this part of the system deserves a great deal of attention.

An electric resistance heater can provide a great deal of heat quickly, but it also consumes a lot of electricity. When we have a heat pump capable of operating at very low temperatures, the transition to auxiliary heating must be configured correctly.

The thermostat, system capacity, building heat loss, and electric heating element capacity must be considered together.

A tight installation makes future maintenance even more important

The Huntingdon photo also shows something we consider from the time of installation: the unit will need to be serviced one day.

The condenser is located in a tight space. We therefore need to consider not only how to install it, but also the possibility of accessing the panels, connections, and components in a few years.

A good location is not defined solely by the phrase “the machine fits here.”

It must be possible to perform:

• inspection and cleaning of the outdoor heat exchanger;
• checking the refrigerant connections;
• electrical inspection;
• access to the service panels;
• clearing snow and leaves;
• checking the drainage beneath the unit;
• filter and indoor unit maintenance;
• thermostat and control system diagnostics.

This is the only list that really matters to the owner after several years of use: all these tasks must remain realistic without having to dismantle half of the exterior landscaping.

MERV 13 filtration available for the central system

The indoor side of the EVOX G3 can also be configured with a filtration module that accepts 1-, 2-, or 4-inch MERV 13 filters. MIDEA indicates that these filters are designed to capture more dust, pollen, particles, and pet hair or dander while helping keep the indoor coil cleaner.

However, we need to adapt the filtration to the system.

An excellent filter installed in a housing that is too small can create excessive pressure drop. In a central system, air quality and mechanical performance must therefore be considered together.

485 communication, 24 V thermostat, and wireless options

MIDEA has also provided several communication strategies.

The documentation describes Sub-1 GHz wireless communication between certain EVOX components, as well as compatibility with 485 and 24 V thermostats communications, including certain configurations using third-party equipment.

This flexibility becomes particularly useful when replacing an old system.

In some homes, the existing cable between the thermostat and the mechanical room does not contain enough conductors for a new traditional communicating system. Avoiding the need to open finished walls simply to add a cable can be a considerable advantage.

Compatibility must nevertheless be confirmed before installation, especially if the owner wishes to take advantage of all the system’s advanced features.

R-454B: the current generation of the EVOX G3

The documentation provided indicates that the range uses R-454B refrigerant, an A2L refrigerant whose global warming potential, as indicated by MIDEA, is 466.

For the installer, this change requires practices and equipment suited to the type of refrigerant used.

For the owner, this mainly means that an EVOX G3 belongs to a recent generation of central systems. During future maintenance, it will therefore be important to use a technician familiar with the procedures applicable to R-454B.

Efficiency that must always be associated with the correct indoor-outdoor pairing

MIDEA’s documentation indicates that the range can reach up to 19 SEER2. However, it clearly shows that the values vary according to capacity.

For example, the table provided shows:

18,000 BTU/h at 19 SEER2 and 10.1 HSPF2; 24,000 BTU/h at 18.6 SEER2 and 10 HSPF2; a combination of 30,000 BTU/h in cooling and 33,000 BTU/h in heating at 17.2 SEER2 and 10.8 HSPF2; and higher capacities with their own efficiency ratings.

That is exactly why we never choose a heat pump based solely on the mention “up to 19 SEER2.”

The owner should ask which precise combination of indoor and outdoor unit appears on the quote.

What about rebates for a MIDEA EVOX G3?

MIDEA’s brochure positions this range among its very high-efficiency systems and indicates that the line exceeds ENERGY STAR Most Efficient specifications in the configurations presented.

However, this brochure alone cannot confirm the amount of a Quebec financial assistance grant for this specific installation in Huntingdon.

For a LogisVert application, the important factor is the actual matching of the models and the reference recognized by the program at the time of installation. The name “MIDEA EVOX G3” or the nominal capacity alone is not enough to confirm an amount.

At AirGreen, we therefore consider the subsidy an additional technical verification: the outdoor model, indoor model, performance reference, and program requirements must match.

This Huntingdon project shows why the location should never be decided after the purchase

Ultimately, the most interesting feature of this installation is its placement.

The outdoor passage is narrow. Two walls partially surround the unit. A window is located directly behind it. The property therefore did not offer many possible locations.

Nevertheless, we were able to install the MIDEA EVOX G3 in a compact, elevated configuration, with its fan oriented toward the open part of the yard.

This is exactly the kind of detail that an estimate based solely on interior photos or the square footage of the house can overlook.

Before a central heat pump installation, we must consider the entire project: outdoor location, snow, service access, refrigerant line routing, electrical supply, duct network, system capacity, static pressure, thermostat, and auxiliary heating.

The unit is only part of the equation.

This installation in Huntingdon shows how a modern central heat pump can be integrated even when outdoor space is limited. With a platform capable of operating at very low temperatures, an Inverter compressor, R-454B, a modular indoor unit, and advanced airflow management, the MIDEA EVOX G3 provides a very interesting technical foundation.

Our role at AirGreen is then to ensure that this technology is installed in a way that is consistent with the building.

This is the same approach we apply to our central heat pump projects in Montreal, Laval, Longueuil, on the North Shore, the South Shore, and elsewhere in Montérégie: size the system correctly, choose the location carefully, and consider from the outset how the system will actually operate in the depths of winter as well as during the peak cooling season.