Installation of a MIDEA EVOX G3 central heat pump in LaSalle, Montreal
In LaSalle, AirGreen installs a MIDEA EVOX G3 central heat pump on a raised stand, with compact connections, inverter technology, R-454B, and an installation adapted to Montréal’s climate.
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.
A clean, elevated central installation designed for the reality of a LaSalle home
At LaSalle, in west Montreal, we completed this MIDEA EVOX G3 central heat pump installation at a brick residence where the outdoor space had to be used intelligently. The site photo shows a typical HVAC renovation in an urban area: a relatively narrow side facade, existing lines, an electrical disconnect panel immediately nearby and little reason to clutter the ground with a large concrete pad.
We therefore installed the MIDEA EVOX G3 outdoor unit on a raised metal structure, directly alongside the facade. The unit remains well clear of the ground, while the refrigerant lines connect to a light-colored line-hide cover installed against the brick wall. The electrical disconnect is also positioned nearby, allowing the technical components to be grouped in a compact area rather than spread across the entire facade.
This project accurately represents the type of project we encounter in LaSalle, Montreal, Laval, Longueuil, on the North Shore and the South Shore: choosing the system is not enough. The climate, snow, defrost cycles, existing ductwork and the building’s actual architecture must also be taken into account.
The EVOX G3 belongs to the family of MIDEA inverter ducted central systems, developed for the replacement and modernization of forced-air heating and cooling systems.
The first challenge: creating a stable base without sacrificing ground-level space
In the photo, the outdoor unit does not rest directly on the ground. It is mounted on a rigid metal frame that keeps the heat pump at an appropriate height above the ground.
This choice is particularly relevant in Montreal.
In winter, an outdoor heat pump is exposed to several conditions that are not encountered during a summer installation:
- snow accumulation;
- repeated freeze-thaw cycles;
- water produced during defrost cycles;
- ice that may form beneath the unit;
- leaves and debris;
- persistent moisture near the property.
A unit installed too low can quickly become surrounded by a significant amount of snow or ice. By raising it, we create clearance that facilitates water drainage, inspection of the base, and future maintenance.
In this LaSalle project, the metal structure supports the machine independently of the ground and keeps the underside away from debris and moisture.
A clear discharge side
The MIDEA EVOX G3 outdoor unit uses a large front-mounted fan with horizontal discharge.
The manufacturer's documentation explains that this concept combines a horizontal fan with a vertical heat exchanger to create a more uniform airflow across the exchange surface. MIDEA links this design to better thermal efficiency as the outdoor temperature drops.
In our installation, the fan blows toward an open space.
This is important because the air discharged by a heat pump must be able to disperse normally. A wall that is too close, a fence, an accumulation of materials, or dense vegetation can cause air recirculation and impair operation.
An accessible service side
The photo also shows one of the unit's technical sides.
We can see:
- the refrigerant lines;
- the connections;
- the line-set cover;
- the electrical disconnect;
- and access to the condenser's service section.
This aspect is essential to us.
An installation is not evaluated only on the day it is completed. In a few years, a technician may need to measure pressures, inspect connections, access components, or perform maintenance.
It is therefore important never to install the unit in a location where its service side becomes practically inaccessible.
An installation that limits the length of visible piping
The line route was also arranged compactly.
The refrigerant lines leave the outdoor unit and quickly reach a light beige line-hide placed against the brick wall. This solution protects the lines while avoiding exposed pipes on the facade.
For a brick house like this one, we generally aim to limit detours.
A more direct route often means:
- a cleaner-looking installation;
- lower risk of damage;
- less unnecessary length;
- easier identification of the lines;
- easier access in case of service.
The photo also shows good separation between the system and the ground, which helps better protect the lines located near the unit.
Why low temperatures really matter in LaSalle
When a homeowner compares a central heat pump in Montreal, winter performance should be one of the main criteria.
The EVOX G3 documentation indicates continuous operation down to -30 °C for the Extreme Heat version. MIDEA also presents, based on tests on a three-ton system, a heating capacity that can reach 100% at around -25 °C, with a COP that can reach approximately 1.9.
However, this information warrants an important clarification.
The statement “operation down to -30 °C” does not mean that all EVOX G3 versions deliver exactly the same heating output at that temperature.
Actual performance depends on:
- of the model;
- of the tonnage;
- of the indoor-outdoor pairing;
- of the outdoor temperature;
- of the ductwork;
- of the home's thermal load.
This is why we never choose a heat pump solely because its brochure displays an impressive minimum temperature.
The M-Powevi technology used by MIDEA
MIDEA also describes its M-Powevi compressor technology, designed to support performance in very cold weather.
According to the documentation, when conditions become extreme, the system injects intermediate-temperature vapor to increase the flow of compressed refrigerant and thereby improve heating capacity. The manufacturer also mentions a high-efficiency compressor motor and an optimized discharge path.
For us, this type of technology makes perfect sense in an installation intended for Montreal's climate.
A central heat pump is no longer simply an air conditioner with a bit of heating added in the fall.
It becomes a major component of the annual heating system.
What capacity was installed on this project?
The photograph clearly identifies the MIDEA EVOX G3, but the exact model number is not legible enough to honestly confirm the installed capacity.
We therefore prefer not to guess the tonnage.
The EVOX G3 lineup includes several nominal cooling capacities, including:
- 18 000 BTU/h;
- 24 000 BTU/h;
- 30 000 BTU/h;
- 36 000 BTU/h;
- 48 000 BTU/h;
- 54 000 BTU/h.
The technical table also provides the main pairings between indoor and outdoor units, including the MAUSE and MO1HE series.
For a serious quote, this exact pairing must be used to verify performance.
Up to 19 SEER2 depending on the capacity
The EVOX G3 lineup can achieve impressive energy performance figures.
MIDEA advertises up to:
- 19 SEER2;
- 12.5 EER2;
- 10.8 HSPF2;
- COP up to 2.14 at 5 °F.
However, the precise figures vary depending on the capacity.
For example, the documentation states:
- 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.
We emphasize this point because the expression “up to 19 SEER2” should not be interpreted as the performance of every EVOX G3.
Sizing remains more important than an efficiency rating
A heat pump’s efficiency is important, but it does not replace proper sizing.
In LaSalle, we encounter homes of very different sizes, ages, and insulation levels.
Two properties with the same area may require completely different capacities depending on:
- insulation;
- the windows;
- air infiltration;
- wind exposure;
- the orientation;
- the area actually being heated;
- the basement;
- the duct system.
An oversized heat pump does not guarantee greater comfort.
Conversely, it can shorten cycle times and impair humidity management during the summer.
An undersized unit can increase reliance on auxiliary heating.
Our goal is therefore always to match the capacity to the building.
This LaSalle project shows why a central heat pump must be designed as a complete system
The outdoor unit is only half of the installation
The photo shows the MIDEA condenser, but a central heat pump also depends on its indoor unit.
Warm or cool air must circulate throughout the house through a duct system.
If this duct system is improperly sized, restrictive, or unbalanced, even an excellent outdoor unit will not be able to provide optimal comfort.
That is why installing an EVOX G3 must include an analysis of the blower and static pressure.
Computational Constant Airflow 2.0
MIDEA equips the EVOX G3 with a technology called Computational Constant Airflow 2.0.
The system adjusts the motor and fan speed to help maintain airflow when it encounters different pressures in the duct system.
The documentation indicates a capacity of up to approximately 1.2 in. of water column static pressure, with up to 60 airflow adjustment levels.
MIDEA also specifies that the system can adapt to certain variations related to the ducts, more restrictive filters, or partial obstructions.
This technology is particularly interesting in existing homes in Montreal.
However, this does not mean that it can compensate indefinitely for a poor duct system.
Insufficient return air or ductwork that is too small remains a restriction that must be corrected.
An indoor unit designed for renovations
The EVOX G3 air handler offers several installation configurations.
MIDEA indicates, among others, the following positions:
- upflow;
- downflow;
- right horizontal;
- left horizontal;
- and low-boy applications.
This flexibility is very useful in an existing home.
Mechanical rooms in Montreal often differ greatly from one property to another. Some have a full basement, while others have lower ceilings or ductwork that is difficult to modify.
Being able to reconfigure the indoor unit makes certain replacements much easier.
Widths suited to several older furnaces
MIDEA also indicates widths of approximately 14.5 to 21.5 inches for its indoor units, as well as a power supply that can adapt to 115 V or 208/230 V depending on the configuration.
The manufacturer presents this architecture as a solution intended to facilitate the replacement of certain existing furnaces.
In practice, this is useful because we can sometimes retain much of the ductwork rather than completely rebuilding the mechanical room.
Auxiliary heating up to 25 kW
The EVOX G3 can be equipped with three-stage auxiliary electric heating, with options reaching 25 kW depending on the configuration.
In Quebec, this auxiliary heating plays an important role.
The goal, however, is not to use it continuously.
We want the heat pump to provide as much of the heating as possible, with the electric elements stepping in when the home's load requires it.
The choice of auxiliary heating capacity therefore depends on:
- of the heat loss;
- of the tonnage;
- of the available electrical capacity;
- of the design temperature;
- of the control used.
Compatible with 24 V thermostats
For replacement projects, the control system often presents another challenge.
MIDEA indicates that the EVOX G3 can operate with 485 communication or with traditional 24 V thermostats. The manufacturer also describes a Sub-1 GHz wireless communication option between certain system components.
This flexibility can avoid additional work when the existing wiring is difficult to replace.
In an already fully finished LaSalle residence, running new wires can sometimes represent much more work than expected.
MERV 13 filtration in multiple sizes
MIDEA also offers a filtration module compatible with 1-, 2-, or 4-inch MERV 13 filters.
According to the manufacturer, these filters can help capture more dust, pollen, particles, and pet hair or dander, while also helping keep the indoor coil cleaner.
This improvement must always be evaluated together with static pressure.
A higher-performance but overly restrictive filter can reduce airflow in a poorly designed system.
We therefore always evaluate filtration and ventilation as a single system.
R-454B: the refrigerant used in the EVOX G3 range
The EVOX G3 uses R-454B.
MIDEA states that this A2L refrigerant has a global warming potential of 466 and that it was chosen for this new product range.
This transition requires appropriate installation methods.
We must pay particular attention:
- to the refrigerant connections;
- to the quality of the flare or joints, depending on the configuration;
- to leak-tightness;
- to evacuation;
- to insulation;
- during commissioning.
The change in refrigerant does not lessen the importance of precision on the job site.
What the photo reveals about the finishing details
The photograph from LaSalle shows a project in which the technical components were grouped in a limited space.
We can see:
- the elevated outdoor unit;
- the metal frame;
- the disconnect panel;
- the insulated refrigerant lines;
- the line-set cover;
- and the service side.
This arrangement keeps the system compact rather than spreading the components over several meters of wall.
The light color of the line-set cover contrasts slightly with the brick, but remains consistent with other exterior elements of the building.
The accessibility of the electrical disconnect switch
The disconnect switch is installed immediately next to the condenser.
This proximity is important for future service work.
During maintenance or diagnostics, the technician must be able to electrically isolate the equipment before certain operations.
A visible, accessible, and properly positioned disconnect switch simplifies the work and contributes to a more professional installation.
The defrost water must be free to drain
The clearance beneath the unit visible in the photo is something we consider particularly important.
The water produced during defrosting must not accumulate immediately against the unit.
In an installation of this type, we want to avoid:
- an ice block under the condenser;
- a drainage obstruction;
- an accumulation that reaches the base;
- ground that is constantly saturated beneath the unit.
The raised support provides more clearance.
ENERGY STAR and eligibility for financial incentives
MIDEA documentation indicates that the range shown exceeds the ENERGY STAR Most Efficient criteria mentioned for this category of equipment.
However, this brochure alone cannot confirm a precise amount of Quebec subsidy for the equipment shown in this photo.
To verify an applicable financial incentive, you need to know:
- the exact outdoor model;
- the indoor model;
- the pairing;
- the AHRI number;
- the program rules in effect at the time of installation.
We therefore always prefer to confirm these details before quoting an amount.
Mistakes to avoid in a similar installation
This central heat pump installation in LaSalle highlights several common mistakes.
Place the unit too close to the ground.
Snow and defrost cycles become much more problematic.
Block the service side.
Insufficient access increases the cost and difficulty of future service work.
Add multiple piping detours.
A more direct route is generally cleaner and easier to maintain.
Choose the tonnage based solely on square footage.
The entire building must be assessed.
Ignore static pressure.
A central heat pump depends entirely on air distribution.
Announce the maximum values for the range for all models.
Actual performance varies depending on the capacity and pairing.
An installation adapted to LaSalle and Montréal’s constraints
This project is particularly representative of our approach at AirGreen.
We worked with an existing brick facade, a compact mechanical area, and an outdoor space where it was preferable to keep the ground clear. The EVOX G3 outdoor unit was therefore installed on a raised metal structure, with the connections grouped on the service side and a short path to the wall.
The result combines MIDEA EVOX G3 technology with an installation adapted to the home:
- inverter;
- low-temperature heating;
- R-454B;
- adaptive indoor blower;
- 24 V or communicating compatibility;
- MERV 13 filtration;
- several capacities available;
- modular indoor unit.
For us, that is the difference between selling a heat pump and carrying out a true HVAC installation.
In LaSalle, Montréal, Laval, Longueuil, on the North Shore and the South Shore, we always strive to size the system correctly, respect the building’s architecture, and make the installation as easy to maintain as it is to use.
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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Four mistakes we do not make
Flip each card to see what we do instead.
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?
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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).