A central installation in a restricted side space, with winter clearance and access preserved
At Saint-Lazare, installing this MIDEA EVOX G3 central heat pump required us to work in an outdoor space where every detail mattered. The project photograph shows a very telling configuration: the outdoor unit was installed on the side of the residence, between an exterior door, the house wall, and a raised gardening area. In this type of environment, choosing the right machine is only part of the job. It is also necessary to determine an appropriate height, preserve the passageway, maintain airflow in front of the fan, and ensure a logical route for the refrigerant lines.
The result is a compact installation in which the heat pump rests on two sturdy wall-mounted metal brackets, well above ground level. The large front fan remains completely unobstructed, while the lines leave the unit on the left side and follow the base of the house. This arrangement avoids unnecessarily sacrificing the space available near the door and limits encroachment on the adjacent landscaped area.
The EVOX G3 is part of MIDEA’s line of inverter ducted central systems, designed to modernize or replace existing central heating and air conditioning systems.
The particular challenge of this project: installing a central heat pump without blocking an already occupied space
On this Saint-Lazare property, the outdoor unit had to coexist with several fixed or semi-fixed elements:
- an exterior door immediately to the left;
- a small landing or passageway in front of the door;
- an exterior wall with vinyl siding;
- a planting area or vegetable garden directly in front and to the right;
- the concrete foundation;
- the necessary route for the lines to the interior.
It would have been easy to place the heat pump directly on the ground. However, this choice would have created more clutter, reduced the clearance beneath the unit, and exposed the base of the outdoor unit to accumulations of snow, leaves, soil, and water.
We therefore opted for a wall-mounted installation on raised metal brackets.
This solution addresses several needs at once: it frees up ground space, keeps the unit away from ground moisture, and preserves significant space beneath the heat pump for winter defrost cycles.
Why clearance beneath a heat pump matters so much in Saint-Lazare
A central heat pump used for heating does not operate only on mild days.
During Quebec winters, the outdoor heat exchanger can accumulate frost. The system then periodically enters defrost mode to melt this buildup.
The resulting water must be able to drain away.
If the unit is installed too close to the ground, this water can refreeze beneath the machine, gradually form a mass of ice, and reduce the space available around the base.
The installation visible at our Saint-Lazare job site creates significant clearance underneath. This is especially useful in a yard where the ground is not covered by a large, clear slab, but rather by soil and vegetation.
A front-mounted fan that must remain unobstructed
The EVOX G3 shown in the photograph uses a large front-mounted fan with horizontal discharge.
MIDEA documentation explains that the outdoor design combines a horizontal-discharge fan with a vertical heat exchanger to achieve more even airflow across the heat exchanger's surface. The manufacturer associates this configuration with improved heat-transfer efficiency when temperatures drop.
At our job site, the fan facade is not facing a nearby wall.
This is an essential point.
A central heat pump must be able to draw in and discharge a large amount of air. If objects, a fence, plants, or a wall are placed too close, airflow may be disrupted.
The presence of the vegetable garden and vegetation around the installation therefore deserves long-term attention: the plants must be kept at a sufficient distance so they never obstruct the heat exchanger or the discharge facade.
The passage near the door remains functional
Another interesting aspect of this installation is its proximity to the exterior door.
We avoided placing the machine directly in the path of circulation. Wall brackets free up floor space and preserve a more logical flow near the entrance.
For homeowners, this is a tangible benefit.
A poorly positioned outdoor unit can become a permanent obstacle: it must be walked around every day, complicates building maintenance, and can interfere with snow removal.
Here, we sought to integrate the heat pump into the wall rather than impose its presence in the passageway.
The lines remain grouped at the bottom of the facade
In the photo, we can also see the insulated lines leaving the unit and running along the lower part of the house.
This route is interesting because it avoids multiplying the visible elements in the middle of the exterior siding.
For a central installation, these lines must be properly protected and supported. They connect the outdoor unit to the indoor equipment and are therefore an integral part of the system's performance.
A route that is too long, unnecessarily complex, or inadequately protected can complicate installation and maintenance.
We always aim to prioritize a logical and structured approach.
A central heat pump designed for low-temperature heating
Much of the technical appeal of the MIDEA EVOX G3 lies in its cold-weather heating capacity.
The manufacturer's documentation indicates continuous operation down to -30 °C. It also presents, for a three-ton MIDEA system used as a test reference, a heating capacity of up to 100% at approximately -25 °C, with a COP of up to 1.9.
For a home in Saint-Lazare, this type of performance is much more relevant than a simple summer cooling figure.
However, we must make an important distinction.
A minimum operating temperature does not mean that all EVOX G3 models deliver exactly the same heating capacity at -30 °C. Actual capacities vary depending on the combination, tonnage, and conditions.
That is why we always check the complete system rather than relying on a general slogan.
M-Powevi technology: supporting capacity when cold sets in
For this generation, MIDEA uses its M-Powevi compressor technology.
The manufacturer explains that in very cold conditions, the system can inject intermediate-temperature vapor to increase the amount of compressed refrigerant and support heating capacity.
This type of technology is particularly interesting in a HVAC installation in Quebec, where the outdoor temperature can remain below zero for long periods.
The goal is not simply for the heat pump to “start” when it is cold.
We want it to continue providing a useful amount of heat while limiting reliance on auxiliary electric heating as much as possible.
What EVOX G3 capacity was installed here?
The photograph clearly identifies the MIDEA family, but the nameplate is not visible with enough precision to confirm the system's exact tonnage.
So we prefer not to invent it.
The technical data sheet provided for the EVOX G3 presents several system capacities, including 18,000, 24,000, 30,000, 36,000, 48,000 and 54,000 BTU/h of nominal cooling capacity, depending on the combination used.
The associated outdoor and indoor models include, among others, the following combinations:
- 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.
A central heat pump quote should always specify the exact combination, rather than simply listing “MIDEA EVOX G3.”
Efficiency ratings of up to 19 SEER2
The EVOX G3 lineup has different efficiency ratings depending on the model.
MIDEA states that this family offers up to 19 SEER2, 12.5 EER2, 10.8 HSPF2 and a COP at 5 °F of up to 2.14.
The technical table helps explain the variations:
- the 18,000 BTU version is rated at 19 SEER2, 12.5 EER2 and 10.1 HSPF2;
- the 24,000 BTU unit reaches 18.6 SEER2, 12 EER2 and 10 HSPF2;
- the 30,000 BTU unit is rated at 17.2 SEER2, 12 EER2 and 10.8 HSPF2;
- the 36,000 BTU unit is rated at 17.7 SEER2 and 10 HSPF2;
- the 48,000 BTU unit is rated at 17.5 SEER2 and 9.5 HSPF2.
These figures demonstrate why we avoid using “up to 19 SEER2” as though it automatically represented the performance of all EVOX G3 units.
Sizing remains more important than the maximum available capacity
A central heat pump should never be selected solely because a larger model seems more reassuring.
In Saint-Lazare, as with an installation in Montreal, Laval, Longueuil, on the North Shore or the South Shore, we must take the building's actual heating and cooling load into account.
We examine in particular:
- area;
- insulation level;
- windows;
- airtightness;
- sun exposure;
- the ductwork;
- return-air capacity;
- and the actual winter demand.
An oversized unit is not necessarily more comfortable. An undersized unit is not desirable either.
The goal is to obtain a system capable of modulating properly and working efficiently with the existing ductwork.
This Saint-Lazare project also shows why the indoor unit and ductwork are just as important as the outdoor unit
An air-handling unit designed for renovations
The EVOX G3 was designed to facilitate several replacement projects for existing central systems.
MIDEA indicates indoor unit widths ranging approximately from 14.5 to 21.5 inches, as well as a multivoltage architecture that can accept 115 V or 208/230 V, depending on the configuration.
This detail can become very important in an existing home.
Mechanical rooms do not always have much space, especially when working around a water heater, existing ductwork, or plumbing.
A more adaptable indoor unit can reduce the modifications required.
Six possible configurations for the indoor unit
The documentation also presents a modular design allowing multiple orientations.
MIDEA specifically mentions the following configurations:
- upflow;
- downflow;
- right horizontal;
- left horizontal;
- and several low-boy applications.
This flexibility allows us to adapt the equipment to the actual constraints of the basement or mechanical room.
This is often where the difference lies between a simple replacement and a much more invasive renovation.
Computational Constant Airflow 2.0: working with the ductwork
The EVOX G3 also uses a technology called Computational Constant Airflow 2.0.
According to MIDEA, the system can adjust the motor output and fan speed to better maintain airflow when static pressure changes.
The manufacturer indicates a capacity of up to approximately 1.2 inches of water column of static pressure and up to 60 airflow adjustment levels.
It also specifies that this technology can respond to changes associated with ductwork, more restrictive filters, or certain obstructions.
This adaptability is useful, but it never replaces an inspection of the system.
An undersized duct, insufficient grille, or inadequate return air remains a problem that must be corrected.
Up to 25 kW of auxiliary heating
The EVOX G3 specifications also include three-stage electric auxiliary heating capable of reaching 25 kW, depending on the configuration.
In Quebec, this component plays an important role during the coldest periods.
However, we want to prevent the auxiliary heating from becoming the dominant source too quickly.
The heat pump should continue to provide its share of the heating for as long as its efficiency and capacity remain worthwhile.
24 V control and 485 communication
The EVOX G3 can be used with several control strategies.
MIDEA indicates compatibility with 485 communication as well as conventional 24 V thermostats. The manufacturer also provides a Sub-1 GHz solution that can reduce communication wiring between certain components in some configurations.
This flexibility is particularly useful during a renovation.
It is not always practical to run a new thermostat cable through a fully finished home.
MERV 13 filtration available in several thicknesses
The documentation also provides for a module that can accept 1-, 2-, or 4-inch MERV 13 filters.
MIDEA indicates that this filtration can capture more dust, pollen, particles, and pet hair or dander while helping keep the indoor heat exchanger cleaner.
However, we must always consider this filtration in relation to the system's static pressure.
The best filter is not simply the filter with the highest rating. It must also allow the system to maintain its airflow.
R-454B: the refrigerant for the new-generation EVOX
The EVOX G3 uses R-454B.
MIDEA specifies in its documentation that this A2L refrigerant was selected for the product line and indicates a global warming potential of 466.
This development also affects our installation and service methods.
The preparation of the connections, evacuation, leak testing, and commissioning must be carried out in accordance with the requirements specific to the system and the refrigerant used.
A nearby garden: a detail to monitor over the years
The environment around this Saint-Lazare installation deserves particular attention.
We see a lot of vegetation in front of and to the right of the heat pump.
For now, the fan's front remains unobstructed. But plants can grow quickly during the summer.
We therefore recommend regularly maintaining a clear space around the unit and removing:
- branches;
- leaves;
- weeds;
- debris;
- accumulated snow;
- temporarily stored objects.
This simple maintenance helps preserve good airflow around the heat exchanger.
A wall-mounted installation near a door also requires periodic inspection
Since the unit is installed near a walkway, the owner should also avoid storing objects under or in front of the heat pump.
The area beneath the unit plays a role during winter defrost cycles.
It should therefore remain as unobstructed as possible.
Similarly, metal brackets can be visually inspected during HVAC maintenance to check their fasteners, the condition of their support points, and the absence of abnormal corrosion.
ENERGY STAR: a range feature, but not an automatic rebate amount
MIDEA states in its documentation that the product line presented exceeds the ENERGY STAR Most Efficient specifications mentioned for this category of equipment.
However, this does not make it possible to determine a precise financial incentive for this Saint-Lazare installation from the photo alone.
To confirm a system's eligibility for a given program, we need to know at a minimum:
- the indoor model;
- the outdoor model;
- the exact match;
- the AHRI number;
- and the criteria applicable at the time of installation.
We prefer to verify these elements before quoting an amount.
What this Saint-Lazare installation teaches homeowners planning their own project
This project summarizes several key points.
The best location is not necessarily on the ground.
Here, the wall-mounted installation frees up a significant area near the door.
Height is particularly useful in winter.
It provides additional protection for the unit from snow and leaves room for defrost cycles.
Vegetation must be considered from the time of installation.
A pleasant garden should not become an airflow restriction for the heat pump.
Capacity should never be guessed from the cabinet.
Only the exact models make it possible to determine the BTUs and performance ratings.
The ductwork must be part of the assessment.
A central heat pump never operates independently of air distribution.
Future maintenance must be planned from day one.
The unit must remain accessible, as must its connections and supports.
Why this EVOX G3 is well suited to this type of central system renovation
The MIDEA EVOX G3 offers an interesting combination for homeowners who want to keep or modernize their existing ductwork.
The manufacturer brings together in this generation:
- inverter technology;
- advertised low-temperature operation down to -30 °C;
- R-454B refrigerant;
- multi-position indoor unit;
- 24 V compatibility and communicating capability;
- adaptive airflow;
- MERV 13 filtration;
- and several system capacities.
But our work involves turning these catalog specifications into an installation that is truly suited to the home.
In Saint-Lazare, this means an outdoor unit raised above the ground, positioned away from the main passageway, with a well-cleared front-facing fan and an installation that takes into account both the door and the neighboring garden.
At AirGreen, we apply this same approach to our central heat pump projects in Montreal, Laval, Longueuil, the North Shore, the South Shore, and western Montérégie.
The choice of equipment is important.
But how it is sized, positioned, connected, and integrated into the building is equally important.