Installation of a MIDEA EVOX G3 central heat pump in Pierrefonds-Roxboro, in Montreal's West Island
In Pierrefonds-Roxboro, AirGreen installs a MIDEA EVOX G3 central heat pump on wall brackets: -30 °C system, R-454B, optimized airflow, and HVAC integration adapted to a limited outdoor space.
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The job on one screen
The unit’s data sheet
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 article, chapter by chapter
A compact installation in a narrow side passage, with wall brackets and carefully considered clearances
At Pierrefonds-Roxboro, this installation of a MIDEA EVOX G3 central heat pump perfectly illustrates a type of project we often encounter in the West Island of Montreal: an existing property where the available outdoor space is relatively limited, with a fence, vegetation, a cladding wall and several existing constraints.
In the photo, the MIDEA outdoor unit is installed on metal wall brackets, high enough above the ground to clear the base of the unit. On the left, a chain-link fence and vegetation reduce the available width. On the right, the refrigerant lines, wiring and connections enter the building directly.
The challenge was therefore not simply to find a place to position the heat pump.
We needed to create an installation that would allow:
- good airflow around the unit;
- future access to the service panels;
- sufficient height for Quebec winters;
- a relatively short refrigerant line route;
- a clean integration near the building;
- and logical use of the property's side passage.
At AirGreen, this is precisely the type of situation that demonstrates why the positioning of a central heat pump deserves as much attention as the choice of the model itself.
Why wall brackets are particularly relevant for this project
The outdoor unit does not rest directly on the ground.
We used a support structure attached to the building that keeps the heat pump above the ground. This configuration is particularly useful in an area where the ground can accumulate snow, ice, leaves or other debris.
In heating mode, a heat pump must periodically perform a defrost cycle. Water is then discharged beneath the unit and may freeze when the outdoor temperature is below zero.
If a unit is installed too low, ice can gradually accumulate beneath the base.
By raising it, we create more clearance for:
- defrost drainage;
- snow accumulation;
- ground cleaning;
- visual inspection under the unit;
- and future maintenance.
At Pierrefonds-Roxboro, where winters regularly bring snow, thawing and refreezing, this height is a true technical decision.
A unit with a horizontal discharge that must remain completely unobstructed
The MIDEA EVOX G3 uses an outdoor unit with horizontal discharge, featuring a large front fan.
The manufacturer explains that this architecture combines a horizontal fan with a high-efficiency vertical heat exchanger to promote more uniform airflow across the heat exchanger's surface and support performance as the temperature drops.
In a relatively narrow passage like the one visible on this property, this feature becomes very important.
The large fan must be able to discharge air without immediately encountering an obstacle.
The fence and vegetation visible on the left are therefore elements we must consider when positioning the unit.
After installation, we recommend that the owner keep branches and shrubs trimmed enough so that they do not press against the coil or obstruct airflow.
A heat pump does not need to be isolated in the middle of a large property, but it does need space to breathe.
An installation close to the building, but not positioned at random
The outdoor unit is installed near the wall, allowing the passageway to remain as open as possible.
This type of placement also reduces the outdoor length of the refrigerant lines.
A more direct route generally makes finishing easier and limits the number of visible changes in direction on the facade.
But placing the unit near the building does not mean pushing it against the wall without careful consideration.
We must always take into account:
the clearances specified by the manufacturer, air intake, the service side, and access to the connections.
On this project, the technical section is grouped on the right side, where the lines quickly reach the building.
The service side must remain accessible throughout the system's entire lifespan
This detail is often overlooked.
A heat pump can operate for years without major intervention, but when diagnostics or maintenance are required, the technician must be able to access the valves, panels, and electrical components.
A unit installed too close to a fence or wedged between two structures becomes much more difficult to service.
We therefore consider the project as if we had to return several years later with our tools.
This logic is an integral part of a good HVAC installation.
The climate in Pierrefonds-Roxboro demands more than good summer performance
In Montreal's West Island, a central heat pump must be chosen for both its heating and cooling performance.
MIDEA presents the EVOX G3 Extreme Heat range as capable of continuous operation down to -30 °C. The documentation also indicates up to 100% heating capacity at -25 °C, with a COP of up to 1.9 under the conditions presented by the manufacturer.
However, these figures must be interpreted correctly.
A heat pump that continues operating at -30 °C does not necessarily produce the same capacity at -30 °C as it does at 0 °C.
Actual efficiency varies according to:
- tonnage;
- indoor-outdoor combination;
- building load;
- temperature;
- and airflow.
This is why we avoid presenting the figure “-30 °C” as sufficient data on its own.
The technology used to maintain performance at low temperatures
MIDEA explains that when the system operates in extreme cold conditions, its compressor uses a refrigeration strategy designed to increase the amount of compressed refrigerant and support heat production.
The manufacturer also presents test results for a 3-ton system: up to 2.4 COP at approximately -15 °C and, at around -25 °C, up to 118% of the nominal heating capacity with a COP of 1.92 for the tested system. MIDEA specifies that these results concern a 3-ton system.
This clarification is important.
We do not take a 3-ton rating and automatically apply it to all EVOX G3 configurations.
What capacity was installed here?
The photo clearly shows a unit from the MIDEA EVOX G3 family, but the exact model number is not legible enough for us to honestly state the tonnage of this installation.
We therefore prefer not to make up the data.
The EVOX G3 documentation lists several cooling capacities, including 18,000, 24,000, 30,000, 36,000, 48,000, and 54,000 BTU/h, depending on the pairing.
The correct choice is not based solely on square footage.
For a home in Pierrefonds-Roxboro, we must also consider the insulation, windows, orientation, number of floors, airtightness, ductwork, and actual heating requirements.
Different efficiencies depending on the model
MIDEA announces performance for the EVOX G3 range of up to 19 SEER2, 12.5 EER2, and 10.8 HSPF2, as well as a COP of up to 2.14 at 5 °F, or approximately -15 °C, depending on the applicable pairing.
The technical data sheet clearly shows that these figures change from one capacity to another.
These include:
- an 18,000 BTU/h configuration at 19 SEER2;
- a 24,000 BTU/h configuration at 18.6 SEER2;
- a 30,000 BTU/h configuration at 17.2 SEER2;
- a 36,000 BTU/h configuration at 17.7 SEER2;
- a 48,000 BTU/h configuration at 17.5 SEER2.
This demonstrates why two quotes that simply list “EVOX G3” are not necessarily equivalent.
A central heat pump is only truly effective when the duct network and indoor unit are properly matched.
The role of airflow in an existing home
The outdoor unit visible in the photo naturally draws attention, but the more important half of the system is indoors.
A central heat pump heats and cools the home through an air handler connected to the duct network.
If the duct network is too restrictive, the return air is too small, or the filter is not properly matched, overall performance may suffer.
MIDEA integrates its Computational Constant Airflow 2.0 technology into the EVOX G3, designed to adjust fan speed and power when static pressure varies.
The documentation presents scenarios of up to 1.2 in. of water column and up to 60 airflow adjustment levels.
This flexibility is particularly useful when replacing equipment in an existing home.
But it does not replace a properly designed duct network.
The M-Coil and symmetrical fan of the indoor unit
MIDEA also uses an M-Coil and a symmetrical fan in its indoor unit.
The documentation states that this architecture aims to provide more uniform air distribution through the heat exchanger, with a reduced airflow difference compared with certain conventional designs.
This detail may interest a homeowner less than the SEER2 rating, but it directly affects the quality of heat transfer inside the home.
An indoor design suited to complex renovations
The EVOX G3 range uses a modular architecture called Block N Lock.
MIDEA presents up to six installation orientations for the indoor unit: upflow, downflow, horizontal left, horizontal right, and several low-height configurations.
This is particularly useful in homes in Pierrefonds-Roxboro, Dollard-des-Ormeaux, Kirkland, Pointe-Claire, or Beaconsfield, where the existing mechanical space can impose significant constraints.
We often have to work around an existing beam, water heater, plumbing, or main duct.
A modular indoor unit sometimes allows us to work with the home's architecture instead of modifying it unnecessarily.
A platform designed to replace certain older furnaces
MIDEA states that the indoor unit of the EVOX G3 is available in widths ranging from 14.5 to 21.5 inches, depending on capacity, which corresponds to several residential furnace dimensions.
The documentation also mentions a multivoltage configuration of 115 V and 208/230 V, depending on the application.
This can simplify certain replacement projects, but it never means that a system change should be carried out without analyzing the existing distribution network.
We still need to check:
- the sheet metal;
- the transitions;
- the drainage;
- the ductwork;
- the electrical supply;
- the thermostat;
- and auxiliary heating.
Auxiliary heating up to 25 kW depending on the configuration
The EVOX G3 documentation provides auxiliary heating kits at several levels, reaching up to 25 kW.
In Quebec, electric supplemental heat can be important during certain cold snaps.
However, the goal is not to operate the electric elements as soon as the outdoor temperature drops.
A proper control strategy should allow the Inverter heat pump to provide as much of the heating as possible, then bring in supplemental heat when the building load requires it.
Sizing and programming can therefore directly affect energy consumption.
485 or 24 V control depending on the project
MIDEA provides compatibility with 485 communication as well as conventional 24 V controls.
The documentation presents several scenarios combining EVOX equipment with MIDEA or third-party thermostats.
With the MIDEA communicating thermostat and the SmartHome app, programming, consumption monitoring, comfort control, and diagnostic functions may also be available.
At AirGreen, we adapt the level of control to the project rather than imposing a single solution on every customer.
MERV 13 filtration: worthwhile, but airflow must remain the priority
The platform is also compatible with 1-, 2-, or 4-inch MERV 13 filters, depending on the filtration module. MIDEA indicates that these filters can capture more dust, pollen, particles, and pet hair while helping keep the indoor coil cleaner.
A more efficient filter nevertheless creates more resistance if it is improperly sized.
We therefore still consider filtration together with static pressure and airflow.
R-454B: a new generation of refrigerant
The MIDEA EVOX G3 uses R-454B refrigerant.
MIDEA announces for this A2L refrigerant a global warming potential of 466 and indicates its use in its core EVOX lineup.
For the homeowner, this change is practically invisible in everyday life.
For our technicians, it involves procedures, tools, and practices adapted to this new generation of systems.
The easiest errors to avoid with the outdoor unit
This Pierrefonds-Roxboro installation also provides an opportunity to review a few best practices.
After installation, avoid:
- allow vegetation to grow against the coil;
- install objects directly in front of the fan;
- store materials under the unit;
- allow a snowbank to reach the base of the unit;
- completely enclose the space around the heat pump with a decorative structure;
- modify the ductwork or electrical disconnect without considering service access.
A modern heat pump needs less space than a large older central condenser, but it still needs airflow and reasonable access.
Subsidies: verify the actual pairing before announcing an amount
The technical document provided for the EVOX G3 confirms many characteristics of the product line, but it is not sufficient on its own to determine the exact amount of financial assistance applicable to this installation.
For a subsidy application in Quebec, you need to know the exact indoor unit model, the exact outdoor unit model and the certified pairing.
Only from this precise combination can eligibility or an amount be properly verified.
We always prefer to work this way rather than present financial assistance simply because a quote mentions “MIDEA EVOX G3.”
Why this project reflects our approach at AirGreen
This MIDEA EVOX G3 central heat pump installation in Pierrefonds-Roxboro looks compact and relatively simple in the photo.
In reality, it results from several technical choices.
The unit had to be high enough for winter, accessible enough for servicing and sufficiently clear despite the presence of a fence and vegetation. The front fan had to remain unobstructed. The connections had to reach the building directly without creating an unnecessarily complex outdoor route.
And indoors, the unit still had to be properly matched with the ductwork, filtration, thermostat and auxiliary heating.
It is this combination of equipment, building and installation that determines the final quality of an HVAC system.
At AirGreen, we install MIDEA central heat pumps in Pierrefonds-Roxboro and throughout the West Island of Montreal, including Dollard-des-Ormeaux, Kirkland, Pointe-Claire, Beaconsfield and Dorval, as well as in Montreal, Laval, Longueuil, on the South Shore and the North Shore.
For a furnace replacement, a conversion to a central Inverter heat pump, or an upgrade to an existing system, we always assess the complete installation rather than limiting ourselves to the outdoor unit.
The job tools
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.
How the job unfolds
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 we check on a job like this one
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.
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.
Good habits, once the unit is in place
Six simple habits that keep the unit going. Your list stays on this device.
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.
The right pages, at the right time
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).