Installation of a MIDEA EVOX G3 central heat pump in Le Sud-Ouest, Montreal
In Montreal’s Southwest, AirGreen installs a MIDEA EVOX G3 central heat pump on an elevated wall bracket, with R-454B, heating down to -30 °C, and a neat fit between the basement windows.
In summer, the outdoor unit rejects the house's heat outside.
Generic illustration of this type of installation, not a survey of this job site. Tap a number.
It captures or rejects heat outside. It sits on a level base, above the snow, with free space all around.
The insulated refrigerant lines enter the house through a sealed opening and run to the indoor coil.
A shut-off switch near the outdoor unit isolates it safely for service.
Sitting on the indoor module, it moves heat between the house air and the refrigerant.
Electric furnace or air handler: its fan pushes air through the ducts. The electric backup takes over in extreme cold.
Supply ducts bring air to the rooms; returns bring it back to the unit. Their condition matters as much as the unit's.
It protects the coil and the fan. A dirty filter cuts airflow, so it gets checked regularly.
It runs the heat pump and the backup heat. It must be compatible with the installed system.
In Le Sud-Ouest, a MIDEA EVOX G3 installed to let the façade breathe, preserve the basement windows, and withstand Montreal winters
This MIDEA EVOX G3 central heat pump installation in Le Sud-Ouest of Montreal illustrates a typical challenge of HVAC projects in urban areas: integrating a high-capacity outdoor unit on a façade where every square foot counts, without obstructing existing openings, access for maintenance, or the machine's operation during the winter.
The project photo immediately shows several important decisions. The Midea outdoor unit is secured to wall brackets anchored to the foundation, above a strip of crushed stone. Two basement windows are located on either side of the equipment. A slab walkway runs alongside the house and, most importantly, the heat pump does not sit directly on the ground.
This positioning is particularly relevant in Le Sud-Ouest, where residences often have narrower side spaces than those in suburban areas. We must work with the existing architecture rather than choose the location solely based on ease of installation.
The goal is to preserve:
- sufficient clearance in front of the fan;
- access to the basement windows;
- reasonable space around the service panel;
- a height suited to snow and defrosting;
- a short refrigerant line route to the interior;
- future access for HVAC maintenance;
- an installation that does not unnecessarily take over the yard or walkway.
On this project, the result is compact without making the machine look wedged between two obstacles.
The wall bracket frees up the ground while protecting the heat pump from snow
The first noteworthy element is the installation height.
The MIDEA EVOX G3 is kept several dozen centimeters above the ground. The unit does not sit on a slab placed directly at gravel level.
For a central heat pump in Quebec, this choice has a very practical purpose.
In heating mode, the outdoor unit must operate during periods when snow can accumulate quickly. It also produces water during its defrost cycles. If the condenser is installed too low, several problems can gradually appear:
- snow rising to the bottom of the heat exchanger;
- ice forming beneath the unit;
- reduced space available for drainage;
- more difficult winter maintenance;
- partial obstruction after several storms.
In this installation in Montreal's Sud-Ouest, the wall bracket instead leaves open space beneath the heat pump. The owner will still need to keep the area clear after a heavy snowfall, but the unit begins winter with a significantly more appropriate clearance.
The proximity of the basement windows requires precise positioning
The photo shows a basement window to the left and another to the right of the outdoor unit.
We do not want a heat pump to unnecessarily complicate access to a window, completely block the light, or prevent future work on the frame.
The unit's width and location were therefore integrated into the existing facade.
In Le Sud-Ouest, Verdun, LaSalle, Montreal, Laval, Longueuil, on the North Shore and the South Shore, we regularly encounter this type of constraint. Installations are rarely made on a completely empty wall. We have to work around:
- windows;
- dryer vents;
- electrical conduits;
- meters;
- stairs;
- decks;
- drains;
- service access.
A good central heat pump installation therefore begins well before the electrical connection: it begins with reading the building.
A large front-facing fan that needs to retain its discharge space
The EVOX G3 uses a horizontal discharge architecture. The front-facing fan visible in the photo discharges air directly outdoors.
Midea describes its outdoor unit with a horizontal fan and a vertical heat exchanger, a configuration designed to promote more uniform heat exchange, particularly when the outdoor temperature drops.
This means that the space in front of the unit really matters.
A very close fence, shed, wall, or another outdoor unit directly in front of the fan can promote recirculation of the discharged air.
In this installation, the fan faces the open passage along the residence. This is exactly the type of configuration we are looking for.
The piping run remains short and accessible
To the right of the unit, we can see the refrigerant and electrical connections quickly reach the wall.
Limiting the visible outdoor length offers several advantages:
- fewer exposed lines;
- less risk of mechanical damage;
- a cleaner-looking installation;
- fewer sections of insulation exposed to the elements;
- easier access during a future diagnosis.
The connections must, of course, comply with the manufacturer's requirements, and the total length of the refrigerant circuit depends on the position of the indoor air handler.
What we mainly avoid are unnecessary detours.
R-454B: this EVOX G3 belongs to the new generation of central systems
The EVOX G3 product line uses R-454B, an A2L-classified refrigerant.
Midea states that it selected R-454B for its product line and announces a global warming potential of 466.
For the home's occupants, the system's day-to-day use remains simple: thermostat, set temperature, heating and cooling.
For us, however, this evolution affects installation and service procedures.
Our technicians must work with practices and equipment suited to R-454B, particularly for:
- connections;
- leak testing;
- vacuum evacuation;
- refrigerant recovery;
- future service.
This is one of the reasons why we place as much importance on commissioning as on choosing the heat pump itself.
The EVOX G3 is particularly interesting as a central replacement, but the exact model must be selected according to the home
The MIDEA EVOX G3 is not a single heat pump with a fixed capacity.
The manufacturer's documentation presents a range of central systems from 18,000 to 54,000 BTU/h, depending on the combination of indoor air handler and outdoor unit selected.
In the photo of this installation in Le Sud-Ouest, the nameplate is not legible enough for us to confirm the complete model number and its capacity with certainty.
We therefore prefer not to artificially assign a tonnage to this installation.
This is also an important distinction for anyone comparing multiple quotes.
Two proposals can both mention “MIDEA EVOX G3” while using different capacities and performance ratings.
Performance of up to 19 SEER2, but not in all configurations
Midea documentation lists values for this family that can reach:
- 19 SEER2;
- 12.5 EER2;
- 10.8 HSPF2;
- a COP of up to 2.14 at 5 °F, depending on the combination.
The technical table makes it easier to understand the differences between capacities.
Midea specifically indicates:
- 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 HSPF2;
- 48,000 BTU: 17.5 SEER2, 12 EER2, 9.5 HSPF2;
- 54,000 BTU: 17.5 SEER2, 12 EER2, 9.5 HSPF2.
We must therefore be wary of a comparison limited to the phrase “up to 19 SEER2.”
We want to know the rating of the actual combination being proposed.
Operation advertised down to -30 °C for cold climates
Winter performance is one of the main advantages of the range.
Midea advertises continuous operation down to -30 °C. The documentation also presents results for a three-ton system indicating up to 100% heating capacity at around -25 °C, with a COP of approximately 1.9 under the stated test conditions.
The manufacturer explains that, in very cold conditions, its compressor uses intermediate vapor injection to increase the amount of compressed refrigerant and support heating capacity.
This technology is well suited to Montreal winters.
But one essential point must be clarified: operating at -30 °C does not automatically mean covering 100% of the heat loss of every home at -30 °C.
A well-insulated 2,000 sq. ft. residence and a house of the same size with an older envelope can have very different heating loads.
We do not automatically reuse the tonnage of the old heat pump
When replacing a central system, a common mistake is to assume that the new system must have exactly the same capacity as the old one.
This is not always true.
Since the previous system was installed, the house may have received:
- new windows;
- more insulation;
- an addition;
- a finished basement;
- modifications to the ductwork.
The old equipment may also have been oversized from the outset.
We must therefore analyze the heating load before selecting an EVOX G3 capacity.
An indoor unit designed to facilitate the replacement of certain furnaces
One of the most interesting aspects of the EVOX G3 concerns the indoor module.
Midea lists indoor units approximately 14.5 to 21.5 inches wide, depending on capacity, with dimensions similar to those of several existing residential furnaces. The documentation also mentions voltage adaptability allowing, depending on the configuration, 115 V or 208/230 V.
This design can greatly simplify a replacement.
In many homes in Montreal’s Southwest, mechanical rooms are tight. A furnace may be installed between a water heater, a foundation wall, and a return air duct.
A few extra inches of width can require rebuilding a significant portion of the ductwork.
Six orientations for better adaptation to existing mechanical rooms
The EVOX G3 indoor unit can also be configured in several ways.
Midea’s documentation presents six installation orientations, including:
- upflow;
- downflow;
- horizontal left;
- horizontal right;
- “low-boy” configurations for low-clearance spaces.
The Block N Lock modular system also allows certain modules to be separated and reassembled, making it easier to access more challenging basements, attics, or mechanical spaces.
This flexibility may not look spectacular on a performance sheet, but it can avoid a great deal of remodeling on an actual job site.
The ductwork remains central to performance
A central heat pump works with the existing ductwork.
Even with an excellent compressor, an undersized return air duct or highly restrictive ductwork can create problems:
- insufficient airflow;
- noise at the registers;
- temperature differences between rooms;
- excessive static pressure;
- lower-than-expected efficiency.
The EVOX G3 uses Computational Constant Airflow 2.0 technology.
In its documentation, Midea presents an example in which the system maintains 1,200 CFM when external static pressure varies up to 1.2 in. of water column.
The unit also provides up to 60 airflow adjustment levels, with power and fan speed adjustments to adapt to system and filtration conditions.
This is an excellent ability to adapt.
However, this is not permission to leave a clearly inadequate duct system in place. When a duct needs to be corrected, we prefer correcting the duct rather than asking the motor to compensate continuously.
MERV 13: improve filtration while monitoring static pressure
Midea offers a module compatible with 1-, 2-, and 4-inch MERV 13 filters.
The documentation mentions increased capture of dust, pollen, particles, as well as pet hair and dander, while helping keep the indoor coil cleaner.
In a central system, the entire house benefits from the filtration.
However, we must ensure that the filter media provides enough surface area to avoid creating excessive restriction.
The best filter is not necessarily the one with the highest number: it is the one that provides the desired level of filtration while respecting the airflow required by the system.
Auxiliary heating: up to 25 kW depending on the configuration
The EVOX G3 can accommodate multi-stage auxiliary electric heating.
Midea presents configurations reaching 25 kW, with gradual activation based on temperature variations.
This capacity should be selected based on:
- the heating load;
- the heat pump's capacity in cold weather;
- the power available at the panel;
- the wiring;
- the desired heating strategy.
Automatically installing the largest available component can unnecessarily increase electrical demand.
485 communication, 24 V thermostat, and retrofits
The EVOX G3 platform also offers several control options.
Midea indicates compatibility with its 485 communicating mode and certain 24 V thermostats, with automatic identification of the control mode.
The manufacturer also provides for Sub-1 GHz wireless communication between certain EVOX components and the Midea thermostat, which can reduce the need to run new communication cables.
In an existing building in the Southwest where the walls are already finished, this option can considerably simplify the work.
LogisVert in 2026: assistance depends on the certified combination, not just the EVOX G3 name
For an eligible residential installation, Hydro-Québec currently indicates assistance of $50 per 1,000 BTU/h at -8 °C for an ENERGY STAR-certified heat pump, or $120 per 1,000 BTU/h at -8 °C when it is ENERGY STAR-certified and a cold-climate model, when all program requirements are met. Hydro-Québec also specifies that the assistance is determined based on the installation date.
This amount must not be calculated based on the nominal tonnage shown in a brochure.
You must use the exact combination of the outdoor unit and indoor air handler, then verify its rated capacity at -8 °C and its eligibility for the program.
Since the nameplate of the photographed installation is not legible enough to confirm the complete combination, we are not presenting a specific subsidy amount for this Southwest project.
This is also the method we recommend to every homeowner: always ask which AHRI or ENERGY STAR number the amount quoted in your estimate is based on.
What this Southwest installation really shows
This photo could be summarized as “a MIDEA EVOX G3 on a house wall.”
In reality, it shows much more.
We see:
- a raised central heat pump;
- two preserved basement windows;
- a support secured to the foundation;
- a clear area in front of the fan;
- a short refrigerant line route;
- an accessible service panel;
- an installation suited to a relatively compact urban lot.
This is exactly the type of detail we consider at AirGreen before starting an installation.
In Montreal's Southwest, as elsewhere in Montreal, Laval, Longueuil, the North Shore, and the South Shore, we want to avoid choosing a location solely because it is easy to reach with our tools.
We instead look for a location that will remain logical in winter, during maintenance, after several years, and when another technician may eventually need to work on it.
The MIDEA EVOX G3 provides a highly complete central platform: inverter technology, cold-climate heating, R-454B refrigerant, a modular air handler, advanced airflow management, and control flexibility.
Our work then consists of integrating this technology into a real home, with its windows, foundation, ductwork, electrical panel, and space constraints.
This is what transforms a technical specification sheet into a durable and cohesive HVAC installation.
How it goes, from the first call to the end
The main steps of this kind of job at AirGreen. Every house has its quirks: the estimate brings them out.
We look at the ducts, the current indoor module, the electrical panel and the planned spot for the outdoor unit.
The equipment combination, capacity and price, in writing. We check whether the combination qualifies for assistance programs.
Access protected, old unit disconnected and removed when it is being replaced.
Electric furnace or air handler, with its coil, connected to the supply and return ducts.
On a level base, raised above the snow, with free space all around.
Insulated, they enter through a sealed opening and run to the indoor coil.
Dedicated circuits, accessible disconnect, a thermostat that works with the heat pump and the backup heat.
Leak test, vacuum, start-up, airflow check and a test of both modes.
Filter, thermostat, backup heat in extreme cold: what to know before winter.
- The on-site estimateWe look at the ducts, the current indoor module, the electrical panel and the planned spot for the outdoor unit.
- The quoteThe equipment combination, capacity and price, in writing. We check whether the combination qualifies for assistance programs.
- Getting readyAccess protected, old unit disconnected and removed when it is being replaced.
- The indoor moduleElectric furnace or air handler, with its coil, connected to the supply and return ducts.
- The outdoor unitOn a level base, raised above the snow, with free space all around.
- The refrigerant linesInsulated, they enter through a sealed opening and run to the indoor coil.
- Electrical and thermostatDedicated circuits, accessible disconnect, a thermostat that works with the heat pump and the backup heat.
- Tests and start-upLeak test, vacuum, start-up, airflow check and a test of both modes.
- The walkthroughFilter, thermostat, backup heat in extreme cold: what to know before winter.
What the unit delivers when it is cold
The range as published on airgreen.ca: pick a size to see its capacity in deep cold.
| Size | Heating at −8 °C | Heating at −15 °C | Coldest certified point | COP at −15 °C | SEER | HSPF | Indicative LogisVert aid |
|---|---|---|---|---|---|---|---|
| Midea EVOX G3 · 1.5 tons | 14,700 | 18,600 | −30 °C: 11,800 | 2.12 | 19.0 | 10.1 | $1,764 |
| Midea EVOX G3 · 2 tons | 20,800 | 20,600 | −30 °C: 12,100 | 2.14 | 18.6 | 10.0 | $2,496 |
| Midea EVOX G3 · 2.5 tons | 24,000 | 33,200 | −30 °C: 17,900 | 1.97 | 17.2 | 10.8 | $2,880 |
| Midea EVOX G3 · 3 tons | 33,000 | 37,400 | −30 °C: 27,600 | 1.9 | 18.0 | 10.0 | $3,960 |
| Midea EVOX G3 · 4 tons | 39,500 | 48,000 | −30 °C: 27,200 | 2.0 | 17.5 | 9.5 | $4,740 |
| Midea EVOX G3 · 5 tons | 45,000 | 54,000 | −30 °C: 37,300 | 1.9 | 17.5 | 9.5 | $5,400 |
Data read live from the airgreen.ca page of each size (NEEP / AHRI certified performance). When the title names the installed size, it is highlighted; otherwise the whole range is shown. The aid shown is today’s, using Hydro-Québec’s rule ($120 per 1,000 BTU/h at −8 °C); amounts quoted in the article date from its publication. Only Hydro-Québec confirms the assistance granted.
And at your place?
Two quick checks with real numbers: what heat costs, and what your current heaters add up to in BTU/h.
Baseboards and electric furnaces turn 1 kWh of electricity into 1 kWh of heat. A heat pump delivers more: that is its COP. At Hydro-Québec’s rate D (11.142¢/kWh above 40 kWh a day, since 1 April 2026):
Hydro-Québec: a heat pump can be up to three times more efficient than baseboards for heating in the colder months.
Estimate per kWh of heat, at the chosen temperature, using the certified COP from the product page. Taxes, access charge and backup heat not included.
Conversion: 1 W = 3.412 BTU/h. An indication, not a load calculation: baseboards and furnaces are often stronger than the real need, and they can stay as backup. AirGreen confirms the capacity on site.
What to do, season by season
Three habits per season for this unit. They take a few minutes and prevent many calls.
- Check the indoor module's filter.
- Clear winter debris from the outdoor unit.
- Test cooling before the heat arrives.
- Check the filter more often in peak season.
- Keep registers and returns clear.
- Watch condensate drainage near the coil.
- Change or clean the filter.
- Test heating and backup heat before the cold.
- Book periodic maintenance.
- Clear snow around the outdoor unit.
- Store nothing in front of the indoor module.
- Note any unusual noise or smell and call us.
Which type of equipment for your project?
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What people ask us about this kind of work
Can I keep my current ducts?
What happens in extreme cold?
Furnace, air handler, ducted: what is the difference?
Are there grants?
Do I need a permit?
How much can I save?
How is the LogisVert assistance calculated?
Will my current thermostat work?
Central or wall units: which one?
Does AirGreen hold the required licences?
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Text and photo: a real AirGreen Climatisation & Chauffage job. The diagrams are generic illustrations of the type of installation, not a survey of this job site. Sources of the added figures: airgreen.ca product pages (NEEP / AHRI performance), Hydro-Québec (Heat pumps page, LogisVert, read on 13 October 2026), Régie de l’énergie (rate D as of 1 April 2026).