Replacing an old heating system in a narrow mechanical room in Beloeil
At Beloeil, on the South Shore of Montreal, we completed a central installation that required much more than simply replacing equipment. The project involved integrating a new ELIOS electric furnace compatible with a heat pump using R454B refrigerant into a basement mechanical room already occupied by an old heating appliance, a water heater, several pipes, wiring, and a custom duct network built up over the years.
The site photograph clearly shows the main challenge: available space was limited, while the new unit had to be properly connected to the home’s air distribution system. In an installation of this type, a few centimetres can completely change the work strategy. The necessary service clearances must be maintained, the direction of airflow respected, access to the electrical panels preserved, and the ducts adapted without creating unnecessary restrictions.
Our AirGreen team therefore installed the ELIOS electric furnace vertically on a metal base designed to integrate with the return air. A new supply plenum was fabricated above the unit to connect to the existing network. On the right, a return-air cabinet with a filtration compartment allows air to return to the unit before being heated or cooled.
The result is a compact, accessible central installation adapted to the building’s actual configuration.
An existing mechanical room that imposed its own constraints
The basements of older homes in Beloeil, Saint-Hilaire, McMasterville, and several areas of the South Shore often present a similar situation: the mechanical equipment was added or modified at different times.
The following are therefore frequently found:
- ducts of varying dimensions;
- metal transitions fabricated for an older appliance;
- limited ceiling height;
- exposed joists;
- water or heating pipes in very close proximity;
- several electrical circuits in the same area;
- an old oil- or gas-fired furnace;
- a restricted workspace around the equipment.
At this job site, the old unit is still visible to the left of the new installation. This proximity required careful planning. We had to position the new furnace so as not to block the necessary access points and to allow for the removal, maintenance, or dismantling of the existing components according to the sequence planned for the project.
A central HVAC installation should never be designed solely on paper without taking the job site into account. On-site measurements, duct locations, the actual height of the joists, and the wiring layout determine the quality of the final result.
Why choose an ELIOS electric furnace?
An electric furnace is the indoor component of a central system. Its fan pushes air through the home’s ducts, while its electric elements can generate heat when the heat pump is insufficient to meet demand or when supplemental heating is needed.
In a central heat pump configuration, ELIOS equipment can therefore perform several functions:
- distribute conditioned air during the summer;
- circulate the air heated by the heat pump in winter;
- provide auxiliary electric heating;
- maintain air circulation throughout the different rooms;
- allow the use of a central filter;
- ensure a controlled transition between the heat pump and the electrical components.
The term R454B primarily refers to the refrigerant used by the heat pump and its associated refrigeration circuit. The indoor electric furnace must be designed and approved to operate with the system’s compatible components.
For a central system project, it is not enough to choose an outdoor unit and a furnace that appear to have comparable capacities. The equipment must form a combination recognized by the manufacturer. Component compatibility affects performance, controls, airflow rates, and potential eligibility for certain financial assistance programs.
R454B and New HVAC Installation Practices
The R454B is used in a new generation of heat pumps and central systems. It has a lower global warming potential than several refrigerants used previously.
However, it belongs to the A2L category, which includes mildly flammable refrigerants. This classification entails specific requirements for manufacturers and installers.
For the homeowner, using R454B does not change the system’s daily operation. They adjust the thermostat as they would with any other central heat pump. The differences mainly concern the equipment’s design and the technical procedures followed during installation or servicing.
Our technicians must pay particular attention to:
- tool compatibility;
- the ventilation of the work area;
- the cleanliness of the refrigerant lines;
- the brazing method when required;
- leak detection;
- evacuation of the circuit;
- the refrigerant charge;
- the identification of the equipment;
- the manufacturer’s specific instructions.
Compatible internal components may also include safety or detection devices specified in the system’s design. These components must never be bypassed or removed.
A complete adaptation of the metal ductwork
One of the most visible aspects of this installation in Beloeil is the sheet metalwork. The new furnace did not exactly match the dimensions of the old system. We therefore had to fabricate several sections to properly connect the equipment to the existing ductwork.
The upper supply plenum
Above the ELIOS furnace is a metal transition that connects to the building’s main duct. This component must distribute the air without causing excessive turbulence.
A transition that is too abrupt can increase resistance to airflow. This can lead to:
- more noise;
- reduced airflow in certain rooms;
- high static pressure;
- higher electrical consumption by the fan;
- reduced heat pump performance;
- unnecessary strain on the blower motor.
The shape of the connection must therefore be designed according to the unit’s width, the position of the existing duct, and the space available beneath the joists.
For this project, the vertical transition was fabricated to connect to the upper ductwork while maintaining reasonable access to the front of the unit.
The side air return
To the right of the furnace, we installed an air return cabinet with an accessible compartment. This section carries air from the house back to the furnace.
The air return is often underestimated when a system is replaced. However, a central heat pump cannot provide the expected airflow if it does not receive enough air.
A return that is too small or restrictive can cause:
- whistling at the grilles;
- a significant temperature difference across the unit;
- less effective defrost cycles;
- irregular operation;
- overheating of the electrical components;
- reduced comfort in more distant rooms.
The new return section also allows a central filter to be installed. The front panel remains accessible, making regular replacement easier.
The unit’s lower base
The furnace rests on a metal base designed to direct air toward the unit’s lower intake. This base also helps position the equipment at the proper height for connecting the ductwork.
The system was installed on the basement’s concrete floor. Before commissioning, we verify that the equipment is stable, level, and properly supported. An improperly leveled unit can transmit vibrations or complicate drainage for the associated components.
The importance of airflow in a central heat pump
Airflow is a determining factor in the operation of an ELIOS central system. A BTU capacity listed on a technical data sheet alone does not guarantee that this capacity will actually be delivered throughout the residence.
The fan must be configured according to:
- the heat pump’s capacity;
- the dimensions of the ductwork;
- the static pressure;
- the number of registers;
- the size of the air returns;
- the filter type;
- the operating mode.
Insufficient airflow can cause the temperature at the indoor coil to be too low or too high. Excessive airflow can increase noise and reduce dehumidification during cooling.
During commissioning, we therefore do more than simply check whether air is coming out of the grilles. We analyze the system’s overall behavior and adjust the settings according to the capabilities of the furnace and the installed controls.
Primary heating, supplemental heating, and electric elements
A central electric furnace generally includes a set of heating elements whose capacity must be selected based on the building and the available electrical supply.
The capacity of the elements must not be determined randomly. Capacity that is too low may fail to meet demand during extreme cold. Capacity that is too high may require major modifications to the electrical panel and wiring.
Before installation, we must consider, among other things:
- the calculated heating load;
- the heat pump’s low-temperature capacity;
- the power available at the panel;
- the conductor gauge;
- the required circuit breakers;
- the thermostat’s control strategy;
- the residence’s other electrical appliances.
The heat pump should normally provide a large portion of the heating when conditions allow. The electric elements provide supplemental heat when demand is high or according to the configured control logic.
Incorrect thermostat programming can activate the electric elements more often than necessary. This increases consumption without necessarily improving comfort. Commissioning must therefore include a check of the heating stages and thermostat settings.
An installation designed for future maintenance
The quality of a project is not measured only on the day of installation. The technician who performs HVAC maintenance or a repair must be able to access the components without unnecessarily dismantling half the system.
On this installation, the furnace’s front panels remain accessible. The filter can be removed through the side cabinet, and the control module located above the unit can be inspected.
We pay attention to several essential access points:
- fan panel;
- electrical compartment;
- heating elements;
- filter;
- condensate drain;
- refrigerant connections;
- controls and wiring;
- nameplate.
Leaving functional space around an appliance may seem difficult in a cluttered basement, but this decision significantly reduces future service time.
What this Beloeil project teaches homeowners replacing their central heating
Do not compare quotes based solely on the brand
Two contractors may propose similar furnaces but plan very different ductwork.
A complete quote should specify, depending on the project:
- the furnace or air handler;
- the outdoor heat pump;
- the electrical components;
- the thermostat;
- duct modifications;
- the filter;
- the drain;
- electrical work;
- removal of the old equipment;
- commissioning;
- the applicable warranties.
A lower price may sometimes exclude a duct transition, an air-return correction, or necessary electrical work. These costs then appear once the project has begun.
Have the ductwork assessed before replacing the equipment
A new central heat pump will not automatically correct defects in an existing system.
Before selecting the equipment, it is useful to check:
- if certain rooms receive little air;
- if the return ducts are large enough;
- if the ducts are crushed or disconnected;
- if the filter is too restrictive;
- if air leaks are visible;
- if the system produces significant noise;
- if any registers have been closed off.
In Beloeil, as in Montréal, Laval, Longueuil, on the North Shore or elsewhere on the South Shore, homes in the same neighborhood may have very different systems. Floor area alone is not enough to select a central furnace properly.
Plan the electrical requirements before the technicians arrive
An electric furnace may require a substantial power supply. The electrical panel must be inspected before confirming the capacity of the heating elements.
Common mistakes include:
- assume that an existing circuit can be reused without verification;
- choose electrical components based solely on floor area;
- forget the space needed for new circuit breakers;
- overlook the electrical service’s total capacity;
- plan the panel or wiring after the mechanical installation.
Coordinating the mechanical and electrical work prevents delays and improvised modifications.
Check eligibility for rebates based on the exact combination
Financial assistance programs are not based solely on the brand name. Eligibility generally depends on the exact combination of the outdoor and indoor units, the recognized capacity, the certified performance, and the rules in effect when the project is carried out.
An ELIOS electric furnace installed on its own does not automatically qualify for a rebate. When combined with an eligible heat pump, you must verify the complete model numbers and the corresponding certification reference.
We recommend verifying this information before purchasing rather than assuming that an entire product line is eligible.
Replace the filter according to the home’s actual conditions
The filter visible in the return-air cabinet protects the furnace, heat exchanger, and fan. How often it should be replaced depends on several factors:
- presence of pets;
- renovation work;
- number of occupants;
- continuous fan operation;
- dust level;
- filter type and thickness;
- heating or cooling season.
A highly efficient filter that is too restrictive for the system can reduce airflow. It is therefore important to follow the specifications recommended for the equipment and ductwork.
A central conversion carried out methodically by AirGreen
This ELIOS R454B electric furnace installation in Beloeil accurately reflects our approach to replacing central systems.
We integrated new equipment into an existing mechanical room without overlooking the building’s constraints. The project required coordination between the furnace, ductwork, air return, filtration, controls, and refrigeration components.
The most important elements of this installation are visible in the details:
- a unit installed vertically and securely;
- an upper plenum adapted to the existing duct;
- a custom-made side air return;
- an accessible filter compartment;
- grouped connections;
- clear service panels;
- compact integration despite the limited space.
At AirGreen, we carry out this type of central heating and central air conditioning project in Greater Montreal, including Beloeil, Longueuil, Boucherville, Saint-Bruno-de-Montarville, Saint-Basile-le-Grand, Mont-Saint-Hilaire, Laval, Montreal, as well as the North Shore and the South Shore.
A central electric furnace represents a long-term investment. Its performance and reliability depend as much on equipment selection as on the quality of the ductwork, connections, airflow, and commissioning.
In this project, every element was adapted to the mechanical room rather than forced into a standard configuration. It is precisely this attention to the building’s actual constraints that makes it possible to achieve a clean, functional installation ready to provide comfort to the home throughout the heating and cooling seasons.
