Installation of a MIDEA EVOX G3 central heat pump in Montréal-Est, on the Island of Montreal
In Montréal-Est, AirGreen installs a MIDEA EVOX G3 central heat pump on a raised wall bracket, with winter clearance, Inverter technology, R-454B, and an HVAC installation designed to last.
Take a tour of the installation
Each number is a point we check on site. Switch between summer and winter to watch air and heat move.
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 Montréal-Est, a central installation on a wall-mounted support designed to keep the unit clear, accessible, and ready for the Québec winter
This MIDEA EVOX G3 central heat pump installation in Montréal-Est perfectly illustrates an aspect we consider essential at AirGreen: a high-performance unit must also be installed logically in relation to the building, the climate, and future maintenance work.
In the photograph of this project, the MIDEA outdoor unit is installed against a large light-colored brick façade. It rests on an elevated metal support, firmly attached to the foundation, with enough space beneath the chassis to prevent the unit from being directly at ground level. The large horizontal-discharge fan faces a clear area, while the connections are grouped on the right side of the unit.
The result is visually simple, but this simplicity rests on several technical decisions: support height, fan orientation, access to the service panel, positioning of the lines, clearance in front of the unit, and anticipation of winter conditions.
The MIDEA EVOX G3 is part of the family of ducted Inverter central systems designed by MIDEA for residential heating and cooling projects, particularly for replacing or modernizing existing central systems.
A deliberately elevated installation above the ground
The first detail that stands out in the photo is the height at which we positioned the outdoor unit.
The heat pump does not rest on a small slab at ground level. It is installed on a metal support that creates significant space beneath the unit.
In a climate like that of Montréal-Est, this approach offers several advantages.
It notably helps limit the risks related:
- to snow accumulation;
- to ice produced during defrost cycles;
- to leaves and debris;
- to moisture near the foundation;
- to splashes;
- to maintaining the area around the unit.
When a heat pump operates in heating mode in winter, its outdoor coil may accumulate frost. The unit then automatically performs defrost cycles.
This operation produces water.
If the outdoor unit is installed too close to the ground, this water can freeze beneath the unit and gradually create a mass of ice that complicates operation and service.
The support visible on our Montréal-Est installation therefore leaves a clear area beneath the heat pump, which is a particularly relevant detail for a unit used year-round.
The large front fan must be able to move its air freely
The MIDEA EVOX G3 uses an outdoor design with horizontal discharge.
MIDEA combines this architecture with a horizontal fan and a vertical heat exchanger, a combination designed to create more uniform airflow across the heat exchanger and support heat-exchange efficiency as outdoor temperatures decrease.
This means we cannot simply install the unit wherever there is physically enough space.
The fan face must remain clear.
We particularly avoid pointing it directly toward:
- a very closely positioned fence;
- a wall;
- a solid structure;
- a dense hedge;
- another condenser;
- an area where snow could create an obstacle in front of the unit.
On this project, the fan faces an open space, allowing the heat pump to discharge its air without being enclosed against another surface.
A clear brick facade simplifies future service
The photo also shows that the unit is not wedged between several building elements.
This greatly facilitates HVAC maintenance.
A technician must be able to access several parts of the system over the years:
- the electrical compartment;
- the refrigeration connections;
- the service valves;
- the fan;
- the heat exchanger;
- electronic components.
An installation that is too cramped may work perfectly on the day it is commissioned, then become very difficult to service a few years later.
At AirGreen, we therefore always strive to maintain genuine technical access.
A photo that appears to have been taken before the very final finishing work
In the lower right part of the installation, a cable loop is still visible.
This most likely indicates that the photograph was taken during the final phase of the project, before certain exterior connections were completely finished.
This is an interesting detail because it shows an intermediate stage often absent from final photos.
Before considering an installation complete, we must check:
- connections;
- cable fastening;
- pipe protection;
- electrical connections;
- leak tightness;
- configuration;
- full start-up.
The final appearance comes after these technical checks.
R-454B: the refrigerant used in this new generation of EVOX
The EVOX G3 series uses R-454B.
MIDEA states that it selected this A2L refrigerant for its EVOX line of central systems and publishes a global warming potential, or GWP, of 466.
This transition to A2L refrigerants is one of the major changes in the HVAC industry.
For the installer, this means that procedures, tools, and certain work methods must be adapted to the refrigerant being used.
We must, in particular, comply with the requirements applicable to:
- handling;
- leak detection;
- evacuation;
- recovery;
- the charge;
- commissioning.
For the homeowner, the main concern is having the system installed by a team that actually works with the new R-454B platforms.
A heat pump designed to operate in extreme cold
In Montréal-Est, winter heating capacity is obviously a central consideration.
MIDEA states that the EVOX G3 platform can operate continuously down to -30 °C. The documentation also presents, under the specified test conditions, up to 100% heating capacity at -25 °C, with a COP of up to 1.9. The manufacturer specifies that some of these figures come from tests of a 3-ton MIDEA system.
MIDEA also explains that under extreme cold conditions, the compressor can use intermediate-temperature vapor injection to increase the amount of compressed refrigerant and support heat production.
For a Montréal residence, this feature is much more important than a simple summer efficiency rating.
Available capacities in the EVOX G3 range
The third-generation EVOX is available in several capacities.
The documentation provided includes configurations of:
- 18,000 BTU/h;
- 24,000 BTU/h;
- 30,000 BTU/h;
- 36,000 BTU/h;
- 48,000 BTU/h;
- 54,000 BTU/h.
In the photo of the Montréal-Est installation, the unit's full model number is not legible enough to honestly confirm the installed capacity.
We therefore prefer not to assign a tonnage at random.
To properly document an installation, we always use the exact model numbers of the outdoor and indoor units.
Up to 19 SEER2, but not for all combinations
The EVOX G3 range can reach, depending on the combination:
- 19 SEER2;
- 12.5 EER2;
- 10.8 HSPF2;
- a COP of up to 2.14 at 5 °F, or approximately -15 °C.
The technical table nevertheless shows that these values vary according to capacity.
MIDEA publishes the following efficiency ratings, among those for the combinations presented:
- 18,000 BTU: 19 SEER2;
- 24,000 BTU: 18.6 SEER2;
- 30,000 BTU: 17.2 SEER2;
- 36,000 BTU: 17.7 SEER2;
- 48,000 BTU: 17.5 SEER2;
- 54,000 BTU: 17.5 SEER2.
That is why we never present “19 SEER2” as a universal characteristic of every EVOX G3.
Actual performance must be confirmed with the installed combination.
A central heat pump should not be judged solely by its outdoor unit: indoor airflow is part of the result
The entire HVAC installation must work as a system
The photograph shows the outdoor condenser, but the comfort inside the home depends just as much on the air handler and the ductwork.
For a MIDEA EVOX G3 central heat pump, we must therefore also consider:
- air returns;
- supply ducts;
- transitions;
- grilles;
- filters;
- static pressure;
- fan settings.
A high-performance outdoor unit alone cannot correct severely undersized ductwork.
Computational Constant Airflow 2.0: a blower capable of adapting
The EVOX G3 uses a technology called Computational Constant Airflow 2.0.
MIDEA explains that the blower can adjust its speed and output based on variations in ductwork resistance.
In the documentation, the manufacturer notably illustrates maintaining an airflow of 1,200 CFM at different static pressures, with examples of up to 1.2 in. of water column.
The system also allows up to 60 airflow adjustment levels.
This flexibility is particularly interesting in an existing home in Montreal East, where the ductwork was often installed well before the new heat pump.
What the system can compensate for, and what it cannot correct
However, adaptation should not be confused with a mechanical miracle.
An advanced blower can adjust its operation when the filter changes the resistance or when the ductwork has certain normal variations.
It cannot fully correct:
- an air return that is much too small;
- crushed ducts;
- closed dampers;
- an extremely restrictive transition;
- improperly sized grilles.
In these situations, we need to address the ductwork itself.
An indoor unit designed for renovations
MIDEA developed the EVOX G3 with the goal of facilitating certain central system replacements.
The documentation notably presents an indoor unit design compatible, depending on the configuration, with a 115 V or 208/230 V power supply. The available widths were also designed to match several common existing furnace sizes.
This can simplify a renovation in Montréal-Est when the central ductwork is already in place.
We must nevertheless always measure:
- the plenum;
- the return;
- the available height;
- the mechanical room;
- electrical power supply;
- drainage.
Several possible orientations for the indoor unit
The EVOX G3’s modular design allows different configurations of the indoor unit.
MIDEA presents, among others:
- upflow installation;
- downflow;
- right horizontal;
- left horizontal;
- low-boy configuration for low-clearance spaces.
In existing properties on the Island of Montréal, this flexibility can avoid much more extensive modifications to the ductwork.
MERV 13 filtration available depending on the configuration
The documentation also provides for compatibility with 1-, 2-, or 4-inch MERV 13 filters, depending on the module used. MIDEA indicates that this filtration can help retain more dust, pollen, particles, and pet hair or dander.
However, better filtration must remain compatible with the required airflow.
We therefore always check its impact on static pressure.
485, 24 V communication and control options
The EVOX G3 offers several communication and control modes.
The brochure documents in particular:
- communication 485;
- the 24 V configurations;
- a Sub-1 GHz wireless link between certain EVOX components.
This can facilitate a renovation when the existing thermostat wiring does not easily allow for the addition of a new communication cable.
However, we select the control mode according to the system actually installed and the desired functions.
Auxiliary heating: up to 25 kW depending on the configuration
The EVOX G3 documentation also presents auxiliary electric heating kits of up to 25 kW.
This maximum is not automatically the right capacity for a house in Montréal-Est.
The auxiliary heater must be selected according to:
- heat losses;
- the heat pump’s low-temperature capacity;
- the electrical panel capacity;
- the required backup heating level;
- the control strategy.
An unnecessarily oversized auxiliary heater can create a much higher electrical demand than necessary.
This installation also shows the importance of vibrations
The photo shows pads between the heat pump and its metal support.
This interface matters.
The compressor and fan naturally produce certain vibrations. When the unit is secured to a structure connected to the building, we want to limit the transmission of these vibrations to the house as much as possible.
The support must therefore be:
- rigid;
- properly anchored;
- properly leveled;
- suited to the weight of the unit.
These details directly influence the perceived quality of the installation.
The mistakes we seek to avoid with a central heat pump in Montréal-Est
Placing the unit too close to the ground
Snow and defrosting must be considered before winter.
Placing the unit against an obstruction
The fan and heat exchanger must be able to move enough air.
Forgetting access to the service panels
An installation must remain serviceable.
Selecting the capacity based solely on floor area
Windows, insulation, airtightness, and heat loss greatly affect a home's requirements.
Reusing the ducts without checking the airflow
An existing system is not automatically suited to new equipment.
Presenting the range's maximum performance as that of every unit
The exact combination determines the actual performance.
Subsidy: why the AHRI number remains essential
For an installation in Quebec, the name MIDEA EVOX G3 alone is not enough to confirm financial assistance.
Before announcing an amount, we must verify:
- the outdoor model;
- the indoor model;
- the certified combination;
- the AHRI number;
- the recognized heating capacity;
- the program criteria applicable on the project date.
This approach avoids promising the homeowner a subsidy based on a different capacity or another combination from the same range.
A clean installation that deliberately leaves space around the unit
This MIDEA EVOX G3 central heat pump installation in Montréal-Est stands out for its particularly clear outdoor layout.
The heat pump is centered on a large section of wall.
It is elevated.
The fan is unobstructed.
The ground remains clear.
Access for maintenance remains simple.
The support is visible and structured.
These choices are not spectacular, but they are part of the details that allow an HVAC system to remain practical several years after installation.
At AirGreen, we install central heat pumps in Montréal-Est, as well as in Montréal, Laval, Longueuil, the North Shore, and the South Shore.
The MIDEA EVOX G3 brings its technology: Inverter, R-454B, advertised operation down to -30 °C, advanced indoor airflow management, and several integration options with an existing central system.
Our job is to ensure that this technology is installed in an environment where it can actually operate as intended.
The unit on this job, in figures
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.
The big day, step by step
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 would it look like 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.
Four mistakes we do not make
Flip each card to see what we do instead.
Your own project, step by step
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.
Is your home ready?
Check what applies at your place. A "no" is not a refusal: it is what we sort out during the estimate.
Four statements: true or false?
It all comes down to details you have just seen.
1. A central heat pump uses the house's ducts.
It connects to the existing ducts to heat and cool everywhere.
2. In extreme cold, electric backup heat can take over.
The indoor module (furnace or air handler) works with the heat pump and takes over in extreme cold.
3. The filter only gets changed when the unit breaks down.
A dirty filter cuts airflow. It gets checked regularly.
4. You can reuse the old unit's size without checking.
The house may have changed: insulation, windows, added rooms. Capacity is confirmed on site.
0 / 4 right answers
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?
Is the estimate free?
No question matches. Write to us: we answer.
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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).