Installation of a MIDEA EVOX G3 central heat pump in Saint-Zotique
In Saint-Zotique, AirGreen installs a MIDEA EVOX G3 central heat pump in a corner of the building, on elevated wall brackets: extreme-cold heating, service access, and an HVAC installation designed for Quebec winters.
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 MIDEA EVOX G3 central installation in Saint-Zotique where the location, height, and service access dictated our approach
For this project completed in Saint-Zotique, our AirGreen team installed a MIDEA EVOX G3 central heat pump in an outdoor location that required precise planning. The jobsite photo shows a situation we often encounter in residential renovations: the available space is real, but not unlimited. The heat pump must coexist with a building corner, a foundation, existing electrical boxes, vegetation, and outdoor elements already in place.
We therefore positioned the unit on elevated metal wall brackets, securely installed against the foundation. The large front fan remains oriented toward an unobstructed area, while the connections and service components remain grouped on the side of the unit.
This way of installing a central heat pump is not merely a matter of finish. It takes the unit's year-round operation into account, especially in winter, when a heat pump must manage snow, freezing, defrost cycles, and long operating periods.
The MIDEA EVOX G3 belongs to a family of Inverter central systems developed for ducted applications and high heating efficiency. Midea documentation specifically indicates continuous operation down to -30 °C, a level of performance that requires the outdoor installation to be designed for these conditions.
The most visible detail: the heat pump was installed at an elevated height
In the Saint-Zotique photo, the EVOX G3 is clearly elevated above the ground.
We used a metal structure with two horizontal arms and diagonal braces. The machine rests on this structure rather than directly on a slab or on the ground.
For a HVAC installation in Quebec, this decision is particularly important.
During heating, the outdoor coil may accumulate frost. The system then periodically enters a defrost cycle. This process melts the frost and produces water underneath the unit.
When the outdoor temperature is below freezing, this water can then freeze on the ground.
If the heat pump is installed too low, ice can gradually approach the underside of the cabinet. Add significant snow accumulation, and a unit designed to heat in very cold weather may end up surrounded by the very conditions it is meant to withstand.
The elevation provides more space for:
- drainage of defrost water;
- normal snow accumulation;
- access underneath the unit;
- seasonal cleaning;
- maintaining clearances around the base.
On a MIDEA EVOX G3 heat pump, this preparation is consistent with the equipment's very purpose.
A heat pump designed to keep working when the temperature drops sharply
Midea emphasizes the winter performance of the EVOX G3 platform.
The documentation indicates continuous operation down to -30 °C and shows, under the described test conditions, up to 100% heating capacity at approximately -25 °C, with a COP of approximately 1.9.
The manufacturer also describes its M-Powevi compressor technology. When conditions become very cold, the system uses intermediate-temperature vapor injection to increase the amount of compressed refrigerant and support heating performance.
In a test mentioned by Midea on a three-ton system, the documentation reports up to 118% of rated heating capacity at approximately -25 °C, with a COP of 1.92 under the tested conditions.
We always interpret this type of figure in context: it is manufacturer test data, not an identical promise for every capacity and every building.
For a homeowner in Saint-Zotique, the more important point is this: the EVOX G3 was developed to continue providing heat in conditions where an older conventional heat pump might have depended much more quickly on its auxiliary heating.
Why front discharge is particularly useful in this location
The MIDEA EVOX G3 uses a front-facing horizontal-discharge fan.
In the photo, the fan is directed toward the open space in front of the unit. The corner formed by the two brick walls is behind and to the right of the heat pump, but the main discharge does not blow directly into that corner.
Midea describes this design as combining a horizontal-discharge fan with a high-efficiency vertical heat exchanger. The manufacturer states that this geometry is intended to provide more uniform air distribution across the heat exchanger and good efficiency as the outdoor temperature decreases.
In a relatively compact outdoor space like the one visible in Saint-Zotique, this design makes it possible to work with the building rather than against it.
This obviously does not exempt us from respecting the manufacturer's clearances. We must always keep the intake and discharge areas sufficiently clear.
The building corner requires consideration of future servicing
Another particularity of the project is its corner location.
The heat pump is located near two masonry walls. Several technical enclosures are already present beneath the unit. On the right, an exterior metal element is also visible, while a branch extends down into the upper part of the image.
This context requires us to think about maintenance from the day of installation.
It is not enough to find a location where the machine physically fits.
We must maintain:
access to the panels,
access to the refrigerant connections,
access to the electrical disconnect,
a safe work area,
and the ability to clean the heat exchanger.
A technician working on the system several years later must be able to work without having to dismantle half of the outdoor landscaping.
Vegetation above and around the condenser deserves seasonal attention
The photograph shows a branch above the heat pump.
This is not unusual in a residential installation. However, vegetation changes over time.
A small branch today can become a larger mass a few years later. Leaves can also accumulate on top of the unit or around its heat exchanger.
We therefore recommend keeping the area around the heat pump clear and periodically checking:
- branches;
- leaves;
- debris;
- snow accumulation;
- ice;
- anything stored near the unit.
Good HVAC maintenance also begins with this type of simple observation.
EVOX G3: multiple capacities under the same commercial name
It would be incorrect to present “EVOX G3” as a single heat pump with one capacity.
The Midea brochure describes a range from approximately 18,000 to 54,000 BTU/h, with different performance levels depending on the combination selected. The manufacturer advertises up to 19 SEER2, 12.5 EER2, 10.8 HSPF2, and a COP at 5 °F of up to 2.14 for the range, depending on the configuration.
The Extreme Heat systems shown include:
- MAUSE-H18B-2A + MO1HE-H18B-2A;
- MAUSE-H24B-2A + MO1HE-H24B-2A;
- MAUSE-H30B-2A + MO1HE-H30B-2A;
- MAUSE-H36B-2A + MO1HE-H36B-2A;
- MAUSE-H48B-2A + MO1HE-H48B-2A;
- MAUSE-H60B-2A + MO1HE-H60B-2A.
In the photograph of this installation in Saint-Zotique, the rating plate is not legible enough to confirm the exact capacity of the installed model without ambiguity. We therefore prefer not to artificially assign a precise tonnage to this project.
Actual efficiency depends on the installed combination
The technical documentation clearly shows that we need to look beyond the EVOX G3 name.
The configurations shown include:
- 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, 10.0 HSPF2;
- 48,000 BTU: 17.5 SEER2, 12 EER2, 9.5 HSPF2;
- 54,000 BTU: 17.5 SEER2, 12 EER2, 9.5 HSPF2.
This variation is normal.
A central heat pump should therefore never be selected solely according to a SEER2 rating or simply based on the largest available tonnage.
We must first determine what the house actually requires.
How we size a central heat pump for a house in Saint-Zotique
For a central system project, we consider much more than the square footage.
We analyze, among other things:
- insulation level;
- window type;
- air infiltration;
- actual heated area;
- ceiling height;
- number of floors;
- ductwork configuration;
- air returns;
- available airflow;
- electrical capacity;
- auxiliary heating;
- the behavior of the old system.
A 2,000 sq. ft. house does not automatically require the same capacity as another 2,000 sq. ft. house.
The quality of the building envelope can completely change the heating and cooling load.
Behind the Saint-Zotique outdoor unit: why the EVOX G3 is first and foremost a complete central system
The ductwork can make or break the replacement
The heat pump visible in the photo is only the outdoor part of the system.
Inside, the air handler must properly distribute heating and cooling throughout the house.
A high-performance condenser connected to an inadequate system will never deliver its best results.
Midea uses Computational Constant Airflow 2.0 technology in the EVOX G3. The documentation states that the fan can adjust its output and speed to different pressure conditions in the duct system. It describes operation up to approximately 1.2 in. of water column static pressure and up to 60 airflow adjustment levels.
For a renovation, this adjustment capability is particularly relevant.
A fan that can adapt better does not replace good ductwork
This distinction is essential.
Advanced airflow control can help the system cope with differences in resistance caused by the filter, ducts, or grilles.
But it does not turn a clearly undersized duct into a good duct.
If a duct system has too many restrictions, we must identify the cause:
insufficient return air,
a duct that is too small,
a filter that is too restrictive,
a poorly positioned damper,
or an inadequate sheet metal transition.
The best result always comes from combining properly configured equipment with a properly sized duct system.
A useful modular indoor design for existing basements
Midea designed the EVOX G3 indoor unit with a modular architecture.
The documentation presents up to six possible orientations, including vertical, horizontal, and certain low-boy configurations. The "Block N Lock" system allows the modules to be separated and reconfigured to make it easier to move them through tight spaces.
This feature is directly relevant to renovations.
We often work in basements where the mechanical room already has:
- a water heater;
- an electrical panel;
- plumbing lines;
- finished walls;
- low ceilings;
- narrow access.
Being able to adapt the unit's configuration can avoid disproportionate modifications to the building.
A width designed to replace certain older furnaces
According to Midea, the indoor units in this family use widths ranging approximately from 14.5 to 21.5 inches, depending on capacity. The system can also accommodate a 115 V or 208/230 V indoor power supply in the configurations shown.
This design is intended to facilitate certain central system upgrades.
Nevertheless, we must always verify the actual project before concluding that a replacement will be a direct fit.
The plenums, returns, wiring, and electrical supply must all match.
Auxiliary heat: up to 25 kW available depending on the configuration
Midea documentation provides for auxiliary heating kits of 10 kW, 15 kW, and up to 25 kW, with staged operation.
Sizing this supplemental heat is important.
Too much capacity can unnecessarily increase electrical demand. Too little can limit the available supplemental heat under certain conditions.
We therefore need to consider:
- heat pump capacity;
- building heat loss;
- electrical panel capacity;
- design temperature;
- operating objectives.
485 and 24 V controls: interesting flexibility when replacing a system
The EVOX G3 can operate with 485 communication or with 24 V controls, depending on the configuration.
Midea also presents various options with third-party thermostats and indicates automatic detection of the control mode in the corresponding configurations.
This flexibility can simplify certain renovation projects where thermostat wiring is already in place.
With Midea's communicating solution and the SmartHome app, the documentation also mentions scheduling, monitoring consumption, certain self-diagnostic functions, and remote software updates.
MERV 13 filtration: useful only if the system maintains its airflow
Midea indicates that its filtration module can accommodate 1-, 2-, or 4-inch filters, including MERV 13 in the configuration described.
A MERV 13 filter can capture more dust, pollen, and particles than a very basic filter.
However, each filter adds resistance to the airflow.
Before recommending more advanced filtration, we therefore assess the static pressure and available airflow.
R-454B also marks a significant change for recent installations
The EVOX range described uses R-454B refrigerant.
Midea identifies it as an A2L refrigerant with a GWP of 466.
The owner almost never sees this part of the system.
For our refrigeration technicians, it matters a great deal.
The procedures, tools, and commissioning must be adapted to this generation of refrigerant. An R-454B installation must not be handled exactly like an older R-410A system.
What about LogisVert and rebates?
Midea documentation indicates that the range presented exceeds the ENERGY STAR Most Efficient specifications mentioned by the manufacturer.
This is a good indicator of energy efficiency.
However, the document provided does not confirm Hydro-Québec eligibility for this specific Saint-Zotique installation, and it does not contain a LogisVert amount.
To confirm financial assistance, the exact installed combination must be verified:
outdoor model, indoor model, capacity, AHRI reference and criteria in effect at the time of the work.
We therefore avoid announcing a subsidy amount based solely on the name EVOX G3.
The practical mistakes we want to avoid on an installation like this
Installing the unit too close to the ground
Defrosting and winter accumulation must be anticipated from the outset.
Forgetting that trees and shrubs grow
The area around the condenser must remain accessible and clear over the years.
Using the building corner without analyzing air circulation
A corner can be a very practical location, but only if the unit's clearances are respected.
Concealing the electrical boxes
The service components visible beneath the unit must remain accessible.
Neglecting the indoor ductwork
The performance of a central heat pump depends as much on air distribution as on the condenser.
A compact, elevated installation adapted to the actual building
The photo of this Saint-Zotique installation nicely sums up how we work at AirGreen.
We were working with a brick building corner, a foundation, several existing technical elements and nearby vegetation. We integrated the MIDEA EVOX G3 into this space while keeping the front discharge clear and positioning the unit high enough to better accommodate winter conditions.
The quality of a central heat pump installation is not judged solely by the model selected.
It is reflected in the sizing, support, access, refrigerant line routing, air distribution, thermostat, auxiliary heating and commissioning.
This comprehensive approach is what we apply to our central heat pump installations in Saint-Zotique, Montreal, Laval, Longueuil, on the South Shore and on the North Shore.
EVOX G3 technology offers us many possibilities. Our job is to adapt them to the actual home in order to achieve a coherent, accessible system designed for Quebec's seasons.
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?
Pick what looks like your need.
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?
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).