A central installation in an extremely tight mechanical space, where every inch had to be used intelligently
This MIDEA EVOX G3 electric furnace installation in Deux-Montagnes perfectly illustrates a reality we often encounter on the Montreal’s North Shore : the main challenge is not always choosing the equipment, but successfully integrating it neatly into a mechanical space already built around an older system.
In the photo taken during our work, the constraint is obvious. The new indoor unit MIDEA EVOX G3 is installed in a very narrow opening between a concrete foundation wall, an existing duct network, and an interior door that passes immediately in front of the unit. The insulated refrigerant lines must neatly go around the lower front of the unit before reaching the copper connections. Above, the cabinet must be integrated with the existing plenum with very little space available.
This type of project requires our team to consider the installation as a whole: electric furnace, central heat pump, ductwork, service access, refrigerant circuit, drainage, wiring, and mechanical clearances all have to work together.
In this case, Deux-Montagnes, simply removing the old unit and putting the new one in the same place was not an option. The configuration had to be adjusted so that the new generation of equipment could operate properly while remaining accessible for future HVAC maintenance.HVAC maintenance.
A furnace installed almost to the millimeter in its mechanical space
The first striking detail of this installation is the proximity between the MIDEA EVOX G3 and the door.
When the door is open, it is immediately in front of the right side of the machine. This meant that we had to precisely control the position of the cabinet to preserve access to the panels and connections as much as possible.
In a spacious mechanical room, a few extra inches are not very important. In an installation like this, they can determine whether a technician will be able to remove a panel, access the connections, or perform a diagnosis several years later.
Therefore, we need to verify the following before final fastening:
- the actual available width;
- the door’s path;
- the space required to remove the panels;
- the route of the refrigerant lines;
- electrical connections;
- access to the condensate drain;
- the transition between the unit and the existing ductwork;
- the possibility of carrying out future maintenance without demolishing the room.
This attention becomes particularly important in homes in Deux-Montagnes, Sainte-Marthe-sur-le-Lac, Laval, Montreal, Longueuil, and the North Shore, where several central systems are installed in finished or semi-finished basements with little clearance.
The refrigerant lines visible in the photo: a passage that had to remain compact
On the lower side of the unit, we can see two insulated refrigerant lines returning to the unit connections.
Their path is not chosen at random.
A refrigerant line must follow a reasonable bending radius. We want to avoid kinks, crushing, and unnecessarily sharp changes in direction. In a very limited space, it is therefore necessary to find a route that is compact enough not to obstruct passage while respecting the mechanical constraints of the copper.
The visible insulation around the pipes is also important. It limits unwanted heat exchange and helps prevent condensation on the cold line during cooling operation.
In this Deux-Montagnes project, the connections are located near the bottom of the unit, leaving the upper area relatively clear for integration with the ductwork.
Why the EVOX G3 cabinet is suitable for replacement spaces
The manufacturer specifically designed the EVOX G3 range to facilitate integration into existing buildings.
MIDEA indicates indoor unit widths of approximately 14.5 to 21.5 inches, depending on the capacity. The documentation also mentions a multi-voltage architecture that can accommodate 115 V or 208/230 V, depending on the equipment configuration.
These dimensions are important when replacing an old central furnace, because completely reworking a mechanical room can involve much more work than installing the equipment itself.
On our installation site in Deux-Montagnes, this design philosophy makes perfect sense: the EVOX G3 had to fit into an opening where the available clearance was extremely limited.
A useful modular design when a staircase or door complicates access
The EVOX G3 uses a modular design called Block N Lock.
MIDEA's documentation presents six installation options, including upflow, downflow, right-horizontal, left-horizontal, and certain “low-boy” configurations. The manufacturer also highlights the ability to separate the sections to facilitate handling in hard-to-access locations.
In our central heating and heat pump projects central heating and central heat pump, this modularity becomes particularly useful when the equipment must pass:
- through a narrow door;
- in a basement stairway;
- between several finished walls;
- beneath existing ductwork;
- in a utility room where it is impossible to rotate a large conventional cabinet.
This is not a feature visible once the project is complete, but it can make a huge difference during installation.
What the MIDEA EVOX G3 brings to a modern central system in Quebec
Heat pump operation designed for temperatures down to -30°C
When combined with the corresponding EVOX outdoor unit, the platform was developed to operate in extremely cold conditions.
MIDEA announces continuous operation down to -30°C. The published data for the three-ton system used in the manufacturer's tests also indicates up to 100% heating capacity at -25°C, with a COP of approximately 1.9 under the conditions presented.
For a residence in Deux-Montagnes, this information is much more relevant than a simple nominal performance rating measured at mild temperatures.
The needs of a Quebec home change radically when the temperature drops from a few degrees above freezing to -15°C, -20°C, or lower.
That is why we always evaluate the heat pump based on its winter performance, not solely on its nominal cooling capacity.
Several capacities are available, but the exact model must be confirmed
The range presented by MIDEA includes various combinations ranging from 18,000 to 54,000 BTU/h, depending on the indoor model and the associated outdoor unit.
The manufacturer's technical table includes configurations of 18,000, 24,000, 30,000, 36,000, 48,000, and 54,000 BTU, among others.
In the photo of this installation in Deux-Montagnes, the nameplate is visible, but the characters are not clear enough for us to state a precise capacity with certainty.
We always prefer to be accurate.
The term MIDEA EVOX G3 refers to a product family rather than a single capacity. The capacity must therefore be verified using the actual model number of the installed equipment.
Up to 19 SEER2 and 10.8 HSPF2, depending on the combinations
According to the MIDEA tables, the range can reach up to 19 SEER2, 12.5 EER2, 10.8 HSPF2 and a COP at 5 °F of up to 2.14, depending on the selected combination.
The figures nevertheless vary from one capacity to another.
This is a very important detail when a homeowner compares two quotes for a central heat pump. Two proposals may both mention “EVOX G3” while using different combinations with different performance levels.
We therefore verify the indoor model, outdoor model, and certified combination before presenting the performance figures.
A ventilation system better able to accommodate existing ductwork
Another feature that is particularly relevant to this project is the Computational Constant Airflow 2.0.
According to MIDEA, the system can automatically adjust the blower’s power and speed to maintain the requested airflow despite different duct or filtration conditions. The documentation indicates up to approximately 1.2 in. of external static pressure, as well as a setting capable of reaching 60 airflow levels.
This capability is useful in an existing home because the duct system was often not designed for the new equipment.
But it can never replace good design.
A variable-speed blower cannot fix a poor duct system
If the return-air opening is too small, the plenum is highly restrictive, or several ducts are undersized, the motor will have to work harder.
We therefore need to check the system as a whole.
At our Deux-Montagnes job site, the new unit is connected directly to an existing duct system through a transition fabricated from sheet metal. This adaptation must provide a smooth airflow path rather than simply connecting two different dimensions.
Filtration must also be considered when calculating airflow
The EVOX G3 platform can be paired with filters rated 1, 2, or 4 inches, with stated compatibility for up to MERV 13.
Higher filtration can help capture more particles, dust, pollen, and pet hair.
However, every filter creates resistance to airflow.
For this reason, we never choose a filter based solely on the MERV rating. We also consider:
- its surface area;
- its thickness;
- the furnace airflow;
- the total static pressure;
- the return size;
- the expected replacement frequency.
A modern unit deserves a properly configured air distribution system.
Auxiliary electric heating capable of reaching 25 kW
MIDEA documentation provides three-stage auxiliary heating kits capable of reaching 25 kW, depending on the selected configuration. MIDEA indicates that the stages can be activated and adjusted according to temperature changes.
This does not mean that a 25 kW element is suitable for every home.
Before installing electric heating capacity, we must verify in particular:
- the thermal load of the residence;
- the heating provided by the heat pump;
- the capacity of the electrical panel;
- the conductor gauge;
- the required circuit breaker;
- the auxiliary heating strategy.
In certain residences on the North Shore, the available electrical capacity can become one of the main limiting factors in a conversion project to a central heat pump.
R-454B: a generation of equipment using an A2L refrigerant
On the label visible at the front of the Deux-Montagnes unit, we can see the pictogram associated with the A2L refrigerant.
MIDEA documentation confirms that the EVOX range uses R-454B, with a stated global warming potential of 466.
This transition to R-454B represents a significant change compared with many older systems operating with R-410A.
For the installer, it requires practices adapted to the new refrigerant, appropriate procedures, and particular attention during commissioning and future servicing.
24 V control or 485 communication
The EVOX platform also offers several control options.
MIDEA indicates compatibility with communication 485 or with certain configurations using a 24 V thermostat, with the system able to identify its control mode.
With the MIDEA communicating thermostat and the SmartHome app, the manufacturer also provides features such as schedule programming, consumption monitoring, comfort control, and certain diagnostic functions.
In a replacement, this flexibility can facilitate integration with the existing wiring, subject to the exact configuration of the project.
Subsidies must be verified with the complete combination
For a central heat pump in Quebec, eligibility for financial assistance must never be determined solely because the equipment bears the EVOX G3 name.
We always verify:
- the exact indoor unit model;
- the outdoor unit model;
- the certified combination;
- the corresponding performance;
- the criteria of the program applicable at the time of the work.
This verification prevents us from confusing two combinations that belong to the same product family but do not necessarily have the same performance data or eligibility.
This Deux-Montagnes project shows why installation is just as important as the unit
The photo of this installation tells more than a technical data sheet.
It shows a MIDEA EVOX G3 electric furnace installed in a particularly compact space, a door immediately in front of the unit, a nearby foundation wall, existing ductwork above and behind it, and refrigerant lines that had to be routed neatly despite the very limited available space.
That is exactly when the experience of an HVAC team becomes important.
We must consider what happens on the day of installation, but also five or ten years later, when someone will need to open the unit, replace a component, or perform maintenance.
Among the errors we systematically seek to avoid:
- enclose the unit to the point of making the panels inaccessible;
- create excessive bends in the refrigerant lines;
- build a duct transition that is too restrictive;
- ignore static pressure;
- choose the capacity based solely on the house’s floor area;
- overlook the available electrical capacity;
- install a filter that is too restrictive;
- promise a subsidy without verifying the exact combination.
This MIDEA EVOX G3 electric furnace installation in Deux-Montagnes This neatly sums up how we work at AirGreen: using the equipment’s characteristics to meet the building’s actual constraints, rather than forcing the building to accept an ill-suited installation.
We apply this same approach to central heat pumps, electric furnaces, heating, and air conditioning to Deux-Montagnes, Laval, Montreal, Longueuil, on the North Shore and South Shore.
A good unit is the starting point. Its integration with the ductwork, the building, and the occupants’ actual needs determines the final result.