Installation of a MIDEA EVOX G3 central heat pump in Sainte-Julie on Montreal’s South Shore
AirGreen installs a MIDEA EVOX G3 central heat pump in Sainte-Julie: an inverter system for cold climates, a neatly installed wall mount, R-454B, and integration adapted to the home's central system.
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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
In Sainte-Julie, a central installation where outdoor positioning matters as much as winter performance
On this installation completed in Sainte-Julie, the first visible detail is not an efficiency rating: it is the particularly compact integration of the outdoor MIDEA EVOX G3 against the house. The gray horizontal-discharge condenser is installed on wall brackets anchored near the foundation, a few steps from an exterior door and immediately beside a flower bed.
This configuration effectively summarizes the work required behind a central heat pump. It is not enough to connect a high-performance machine to the existing duct network. We must determine where the outdoor unit can breathe properly, how to keep it above the ground, how to preserve access to the house, and how to prepare the installation for the realities of Quebec winters.
The MIDEA EVOX G3 is an Inverter central heat pump designed for ducted systems. The manufacturer's documentation presents a range from 18,000 to 54,000 BTU/h, with efficiencies of up to 19 SEER2, 12.5 EER2, and 10.8 HSPF2, depending on the selected capacity and indoor-outdoor match.
The exact capacity installed on this project cannot be determined reliably from the photograph alone. This is an important point: the physical size of the condenser never replaces reading the nameplate or validating the AHRI match. For a central installation, we size the system according to the building, not the space available outdoors.
An outdoor unit designed for Quebec's cold climate
For a heat pump installed in Sainte-Julie, January performance obviously carries much more weight than the simple ability to cool in July.
The EVOX G3 documentation states continuous operation down to -30 °C. MIDEA also indicates heating capacity of up to 100% at -25 °C, with a COP of up to 1.9 under the reference conditions presented by the manufacturer.
The compressor technology used is specifically designed to maintain heat output when the outdoor temperature drops. The manufacturer describes intermediate-temperature vapor injection that increases the total amount of refrigerant compressed under extreme cold conditions.
For our customers in Sainte-Julie, Longueuil, Boucherville, Saint-Bruno, Montreal, Laval, the South Shore, and the North Shore, this feature changes how a central heat pump should be evaluated. The question is not simply how many BTUs it produces under rated conditions. We want to know its actual capacity when the heating demand is at its highest.
What the photo shows: a condenser elevated above the ground on wall brackets
On this job, we chose not to place the outdoor unit directly in the flower bed. It rests on two metal wall brackets, keeping the base of the condenser above the ground.
This choice offers several advantages in a Quebec installation.
The unit is less exposed to direct ground moisture and vegetation. It is also easier to keep clear during the winter. A heat pump must be able to draw in and discharge large quantities of air even after a snowfall. A unit installed too low can quickly become surrounded by a snowbank or ice.
In the photo, the fan face remains completely open to the outdoors. There is neither an opaque fence nor a wall immediately in front of the fan. This is important because the discharged air must not be directed straight back toward the outdoor heat exchanger.
However, the proximity of the flower bed imposes a very simple maintenance rule: vegetation must be kept trimmed around the condenser. Plants growing against the heat exchanger can reduce airflow, retain moisture, and complicate future HVAC maintenance.
An installation near the door that requires precise planning
The condenser is located near an exterior door and small wooden steps. In such a situation, every dimension matters.
We must maintain a functional passage, prevent the unit from unnecessarily encroaching on access to the house, and leave enough space for a technician to service it later.
This includes:
- air circulation around the outdoor unit;
- access to the service panels;
- clearance in front of the fan;
- water management during defrost cycles;
- snow that may accumulate around the supports;
- the garden bed vegetation;
- daily passage in front of the door;
- vibrations transmitted to the structure and connections.
These considerations are much more important than gaining a few centimetres by simply placing the condenser in the location closest to the indoor network.
A central heat pump is not a wall-mounted heat pump with larger ducts
In a home equipped with an air distribution network, the MIDEA EVOX G3 central heat pump works with an indoor air handler. The conditioned air is then distributed throughout the rooms via the duct network.
This completely changes the system's behavior.
With a wall-mounted unit, airflow is primarily determined by the unit installed in the room. In a central system, the heat pump must contend with the resistance of the entire network: duct length, branch dimensions, dampers, filter, coils, and static pressure.
MIDEA specifically developed its Computational Constant Airflow 2.0 system to adapt fan operation to network conditions. The documentation indicates a static pressure management capacity of up to 1.2 in. of water column and up to 60 airflow adjustment levels.
For us, this does not mean that a poor duct network automatically becomes acceptable. An overly restrictive duct remains a problem that needs to be corrected. However, this adaptability provides much more flexibility when a modern heat pump is integrated into an existing home.
EVOX G3: a particularly interesting platform for central system replacements
The third-generation EVOX was designed to facilitate modernization projects.
MIDEA indicates in particular that its air handlers can automatically recognize the required power supply and operate at 115 V or 208/230 V, depending on the configuration. The manufacturer has also maintained widths comparable to those of many residential furnaces, approximately 14.5 to 21.5 inches, to facilitate integration into certain existing mechanical spaces.
This design is interesting for our projects in Sainte-Julie and on the South Shore, where we regularly encounter homes that already have an electric furnace, an older central heat pump, or a forced-air system.
When replacing a system, the challenge is generally not just getting the new unit into the mechanical room. We need to check:
The ductwork
A modern Inverter system delivers its best efficiency when airflow is properly adjusted. An undersized return-air duct or overly restrictive ductwork can reduce comfort and increase noise.
The electrical supply
The heat pump capacity, indoor unit, and any auxiliary heating must be compatible with the building's electrical installation.
Supplemental heating
MIDEA provides optional auxiliary elements up to 25 kW, with staged operation and adjustment according to temperature changes.
Auxiliary heating should not become the main source simply because the heat pump or its controls were improperly configured. Its role must be integrated intelligently into the heating strategy.
A modular indoor unit that makes difficult basements and mechanical spaces easier to work with
A part of the EVOX G3 that is not visible in the exterior photograph is particularly interesting for installers: the air handler uses a modular Block N Lock design.
MIDEA provides up to six installation orientations, including upflow, downflow, right horizontal, left horizontal, and certain low-height configurations. The manufacturer highlights the option of separating and reassembling modules to facilitate moving them through restricted stairways, attics, or basements.
In Montreal and in several older areas of the South Shore, we frequently work with narrow basement stairways, limited mechanical doorways, and relatively low ceilings.
A technically excellent machine is not much help if it cannot reach its final location without major demolition. This modularity is therefore a very practical advantage when replacing a central system.
From Inverter technology to R-454B: what you really need to check before choosing an EVOX G3
The stated efficiency ratings vary according to the exact capacity
The technical table for the range clearly shows why we avoid assigning a single SEER2 to all EVOX G3.
According to the combinations presented by MIDEA, cooling capacities range from 18,000 to 54,000 BTU/h. Efficiency ratings change with size: some combinations reach 19 SEER2, while others are rated at 17.2, 17.5, 17.7, or 18.6 SEER2. Published HSPF2 values also reach up to 10.8 depending on the pairing.
That is why a homeowner should not choose a central heat pump simply because an advertisement displays “up to 19 SEER2.”
The important word is “up to.”
To determine the actual performance of the proposed system, we must verify the model numbers of the outdoor unit and indoor unit, as well as their certified combination.
R-454B is now part of the design of this generation
MIDEA uses R-454B refrigerant for this product line. The documentation indicates a global warming potential, or GWP, of 466 and classifies this refrigerant in the A2L family.
This change has direct consequences for an HVAC company.
Installing an R-454B system requires working with the procedures, tools, and practices suited to this generation of refrigerants. This includes refrigerant circuit handling, leak tightness, commissioning, and service practices.
For the homeowner, the message is simpler: when replacing an old central heat pump, make sure the installer truly understands the latest-generation equipment and refrigerants.
Communication that can be wireless between the main components
The EVOX G3 also incorporates an unusual control architecture for a central system.
MIDEA features Sub-1 GHz communication that can eliminate traditional communication wiring between the outdoor heat pump, the air handler, and the MIDEA communicating thermostat. The system also remains compatible with 485 or 24 V configurations, including certain third-party equipment and thermostats.
In a replacement, this aspect can reduce the need to reroute a long stretch of wiring in a finished home.
Nevertheless, we review each project individually. The technical possibility of using an existing thermostat does not necessarily mean that this choice will make use of all the system's available functions.
MERV 13 filtration and airflow control
The quality of a central system installation also depends on what happens before the air reaches the rooms.
MIDEA provides a filtration module compatible with 1-, 2-, or 4-inch MERV 13 filters. The goal is to better capture dust, pollen, particles, and pet hair while providing greater protection for the indoor coil.
However, a common pitfall must be avoided: installing a highly restrictive filter without checking the system's available pressure.
The best filter is not necessarily the one with the highest number. We must consider filtration, airflow, and the system's actual static pressure simultaneously.
Smart control and consumption monitoring
With the MIDEA communicating thermostat and the SmartHome app, the platform can schedule operating times, manage temperature and airflow, monitor certain system parameters, and view electricity consumption. MIDEA also provides remote diagnostic and software update functions.
For an Inverter central heat pump, these checks are particularly important. The goal is not to force the machine to operate continuously at full capacity, but to allow it to adjust its output to the home's actual needs.
LogisVert: a central heat pump may be eligible, but the matching must be verified
For homeowners shopping for a central heat pump in Sainte-Julie, the question of Hydro-Québec rebates is unavoidable.
The current terms of the LogisVert program allow a central ducted air-source heat pump consisting of an indoor unit and an outdoor unit to be eligible, subject to compliance with all program conditions. In particular, the complete system must be new and ENERGY STAR certified. Hydro-Québec currently indicates assistance of $50 per 1,000 BTU/h at -8 °C for an ENERGY STAR heat pump and $120 per 1,000 BTU/h at -8 °C for an ENERGY STAR – Cold Climate model.
This does not mean that simply writing “MIDEA EVOX G3” on an invoice is enough to obtain a specific amount.
Eligibility and financial assistance must be calculated based on the exact matching of the indoor and outdoor models, the rated capacity at -8 °C, and the list in effect on the installation date. Hydro-Québec also points out that its lists and the amounts associated with different models may change over time.
At AirGreen, we therefore prioritize verifying the exact model rather than making an approximate estimate based solely on nominal capacity.
What this Sainte-Julie installation shows particularly well
This project is interesting because the photograph looks simple: a gray heat pump against light-colored exterior siding.
In reality, several technical decisions come together in exactly this location.
We have a MIDEA EVOX G3 central heat pump with horizontal discharge, a wall bracket that keeps the unit above the flower bed, an adjacent door that must remain accessible, service clearance to preserve and a climate where snow accumulation and defrost cycles must be considered from the outset of the installation.
Inside, the same project must be designed with equal precision: capacity, airflow, static pressure, filtration, auxiliary heating, thermostat, duct network and air handler configuration.
This is precisely why we consider that a central heat pump installation begins well before the condenser is mounted.
For a home in Sainte-Julie, Longueuil, Boucherville, Saint-Bruno, Montréal, Laval, the South Shore or the North Shore, the best system is not simply the one with the highest SEER2 rating in a brochure. It is the one whose capacity matches the building, whose duct network allows the required airflow and whose outdoor installation remains functional when the mercury drops below zero.
The MIDEA EVOX G3 offers particularly interesting technical features for this type of project: operation down to -30 °C, Inverter technology, R-454B refrigerant, modular indoor unit, advanced airflow management and communication control capabilities. But all these features still depend on the same foundation: proper sizing and an HVAC installation carried out according to the home's actual constraints.
This project in Sainte-Julie shows exactly this approach. The equipment fits into an outdoor space that is already in use, the ground and flower bed remain clear beneath the unit, and the fan retains a large unobstructed airflow area. It is a relatively visually discreet installation, but it has been technically designed to become a permanent component of the property's heating and cooling system.
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).