A central upgrade carried out in a very cluttered mechanical room
At Hemmingford, we installed an ELIOS electric furnace integrated with a Central-Elios central heat pump system using R454B refrigerant in a mechanical room where planning was just as important as the equipment itself.
The construction-site photo shows a particularly tight configuration. The indoor unit had to be positioned between a wooden structure, an old assembly of metal ducts, several refrigeration lines, drainage pipes, control wiring, and a large flexible duct that was already in place. Part of the space was also occupied by an old air-handling system and its ventilation network.
In such a basement, the job does not simply consist of removing one unit and placing the new one in the same location. Each connection must be analyzed to preserve:
- airflow;
- access to the service panels;
- the stability of the unit;
- condensate drainage;
- the safety of the electrical connections;
- the integrity of the refrigeration lines;
- compatibility with the existing duct system;
- the possibility of carrying out future HVAC maintenance.
We therefore adapted the installation to the actual building rather than imposing a standard configuration that would have been poorly suited to the available space.
What the photo of this Hemmingford installation shows
The ELIOS unit is installed vertically and rests on a lower metal plenum. This base serves both as a support and as a connection section to the return-air system.
The upper section is connected to an existing duct by a transition fabricated and sealed on site. The visible metal surfaces around the connection show that part of the old system had to be retained and then adapted to the dimensions of the new unit.
We can also distinguish the following on the side of the unit:
- a large-diameter refrigeration line covered with black insulation;
- a copper liquid line;
- side refrigeration fittings;
- a PVC drainage pipe;
- several control cables;
- a flexible ventilation duct running very close to the unit;
- existing metal ducts with several changes in direction.
This density of components required a precise work sequence. Installing the unit first without planning the ductwork could have made some connections inaccessible or blocked panel removal.
An electric furnace at the heart of a complete central system
The expression ELIOS R454B electric furnace can be confusing. R454B is not the furnace's fuel or heating capacity. It is the refrigerant that circulates between the heat pump's outdoor unit and the indoor coil.
The indoor component performs several functions:
- it circulates air through the ducts;
- it enables heat exchange with the refrigerant;
- it distributes heating or cooling throughout the house;
- it can accommodate auxiliary electric elements;
- it filters the air before redistribution.
The Central-Elios documentation lists optional electric heating coils from 3 to 25 kW, depending on the selected configuration. These elements supplement the heat pump during periods of high demand, certain defrost cycles, or when the control strategy calls for additional electric heat.
Their capacity must be selected according to the home's heating load and the available electrical capacity. Installing more kilowatts than necessary does not automatically improve comfort and may place an unnecessary load on the electrical panel.
The main challenge: working around an existing duct network
The main duct above the furnace did not exactly match the dimensions of the new cabinet. We therefore fabricated a metal transition to connect the two sections.
This transition had to be compact enough to fit beneath the existing ducts without excessively restricting the airflow. A reduction that was too abrupt would have created more turbulence and resistance.
In a central heating system, the shape of the ducts directly influences:
- static pressure;
- noise at the grilles;
- fan efficiency;
- supply-air temperature;
- airflow distribution between rooms;
- motor electricity consumption;
- cycle duration.
We therefore sealed the metal connections to limit air leaks in the mechanical room. A leak near the furnace may seem insignificant, but it reduces the amount of air actually delivered to the more distant rooms.
Preserving front access despite the limited space
One of the important details of this installation is the orientation of the service panels. Even in a tight space, the main face of the furnace must remain accessible.
A technician might eventually need access to:
- the fan motor;
- the electrical components;
- the control boards;
- the safety sensor;
- the electrical connections;
- the indoor coil;
- the condensate pan;
- the filter or its housing section.
The proximity of the flexible duct and the wooden structure therefore had to be managed without blocking access to the unit.
A compact installation is successful only if it remains serviceable. Saving a few inches on the day of installation at the cost of making future repairs inaccessible is a false economy.
Managing R454B refrigerant lines
The black insulated line visible in the photo carries refrigerant between the indoor coil and the outdoor unit. A second copper line completes the circuit.
The Central-Elios technical data sheet indicates, for the listed capacities from 24,000 to 60,000 BTU/h, a 3/8 in liquid line and a 3/4 in gas line. The published maximum lengths range from 164 to 246 feet, depending on the system capacity, with a maximum height difference ranging from 82 to 98.4 feet.
These values must always be validated against the project’s exact model numbers. The photo does not reliably confirm the precise capacity installed in Hemmingford; we therefore avoid arbitrarily assigning a BTU rating to this unit.
When installing the lines, we must avoid:
- bends that are too tight;
- crushed pipes;
- friction against the sheet metal;
- incomplete insulation;
- mechanical stress on the fittings;
- a route that blocks the service panels;
- prolonged contact with a heat source.
R454B also requires work methods compatible with its characteristics. The circuit must be checked, pressurized according to the appropriate procedure, evacuated, and commissioned using suitable tools.
Leak detection integrated into the system
The Central-Elios range is equipped with a refrigerant leak detection device. According to the manufacturer’s documentation, this sensor monitors the system and, in the event of an anomaly, can stop the compressor, maintain airflow, and generate a service alert.
This function is particularly important with next-generation refrigerants. However, it does not replace a compliant installation.
Reliability always depends on:
- properly prepared refrigerant connections;
- a leak test;
- an adequate vacuum;
- a verified charge;
- correct sensor wiring;
- an appropriate control configuration;
- a complete start-up.
Organized drainage in a limited space
The white piping installed near the base serves to drain the water produced in cooling mode.
When humid air from the home passes over the cold coil, the moisture turns into water. This condensation falls into a pan and must then be directed to a drain.
Depending on the capacity, the Central-Elios line removes approximately 2.05 to 5.87 litres per hour of moisture under the specified test conditions. The drainage system may therefore need to handle an appreciable volume of water during a hot, humid day.
We positioned the piping to:
- ensure proper drainage slope;
- prevent stress points;
- maintain access to the connections;
- limit the risk of overflow;
- facilitate future cleaning;
- prevent the pipes from being crushed or displaced.
A water leak around a furnace should never be ignored. It may be caused by a clogged drain, an improper slope, a loose connection, or buildup in the drain pan.
A metal base adapted to the air return
The unit rests on a sheet-metal base that connects the blower to the existing air return. This section is essential because the system must draw in enough air before heating or cooling it.
An undersized return can cause:
- noisy air intake;
- excessive static pressure;
- reduced airflow;
- overheating of the electrical elements;
- lower efficiency;
- uneven distribution;
- increased motor wear.
In older homes in Hemmingford, the ductwork was not always designed for a modern variable-capacity heat pump. It is therefore necessary to check whether the return air, supply ducts, and grilles can handle the required airflow.
We pay just as much attention to this hidden part as to the visible unit. A high-performance furnace connected to a restrictive duct network will not deliver the expected results.
A central heat pump designed for the cold climate of Montérégie
The Central-Elios system is offered as a central heat pump for cold climates, designed to continue heating down to an outdoor temperature of -30 °C.
The documentation indicates that the range maintains 69% to 76% of its nominal heating capacity at -30 °C, depending on the model, and can deliver up to 100% of its nominal capacity at -20 °C.
This feature is relevant in Hemmingford, where a heat pump must be able to operate for long periods below freezing.
Capacities ranging from 24,000 to 60,000 BTU/h
The Central-Elios range includes five nominal capacities:
- 24,000 BTU/h;
- 30,000 BTU/h;
- 36,000 BTU/h;
- 48,000 BTU/h;
- 60,000 BTU/h.
According to the technical data sheet, the published maximum heating capacities reach up to 30,000, 38,500, 48,000, 57,300 and 64,500 BTU/h, depending on the model and operating conditions.
The installed capacity should be selected based on a load calculation, not solely on the living area.
We consider, among other factors:
- home insulation;
- air infiltration;
- window quality;
- wind exposure;
- ceiling height;
- the number of floors;
- the presence of a heated basement;
- solar gains;
- duct capacity;
- the auxiliary heating capacity.
A rural home exposed to wind near Hemmingford may require more heating than a property of similar size sheltered by neighboring buildings.
Up to 18.3 SEER2 and 8.6 CPSC2
Published performance varies by capacity. The range reaches up to 18.3 SEER2 in cooling and up to 8.6 CPSC2, with models certified ENERGY STAR V6.1 cold climate.
The technical table indicates, among other things:
- 18.3 SEER2 for a capacity of 24,000 BTU;
- 16.8 SEER2 for 30,000 BTU;
- 17.3 SEER2 for 36,000 BTU;
- 16.5 SEER2 for 48,000 BTU;
- 16 SEER2 for 60,000 BTU.
These values apply to the combinations indicated by the manufacturer under standardized test conditions. They should not be used to identify the unit’s capacity based solely on its appearance.
Inverter operation for a more stable temperature
Inverter technology allows the outdoor compressor to vary its speed rather than operating only at full power or being switched off.
This modulation offers several advantages in a home equipped with ductwork:
- more consistent indoor temperature;
- longer cycles;
- fewer abrupt starts;
- better adaptation to partial-load needs;
- generally quieter operation;
- consumption better matched to the actual load.
Performance nevertheless depends on the indoor airflow setting. The compressor can modulate effectively only if the fan and ductwork allow adequate heat exchange.
A horizontal-discharge outdoor unit
The outdoor section of the Central-Elios system uses a horizontal discharge. The documentation states that it can be up to 40% more compact than some vertical-discharge units and that it features an automatic fan-reversal cycle to help clear debris from the coil.
The published nominal sound levels for the outdoor units range from 60 to 65 dB(A) depending on the capacity.
The outdoor location must still meet the required clearances. A compact unit must not be enclosed between walls or obstructed by snow.
Incentives must be verified using the exact combination
Cold-climate ENERGY STAR certification may be relevant to certain financial incentive programs. However, it does not automatically guarantee a project's eligibility.
The following must be confirmed:
- the exact indoor unit number;
- the exact outdoor unit number;
- the recognized combination;
- the system capacity;
- the installation date;
- the type of property;
- the program conditions at the time of application;
- the required documents.
The technical data sheet lists the EAHMA indoor models and the ESHMA or ESHMB outdoor models for the five available capacities. Before quoting a financial incentive amount, we always verify the combination that was actually installed.
Mistakes to avoid in a mechanical room like this one
Adding storage in front of the unit
The visible space around the furnace is already limited. Boxes or shelves placed in front of the panels could prevent maintenance or repairs.
Moving the refrigerant lines
The lines must not be used as supports or pushed aside to gain space. Excessive strain can damage a connection.
Crushing the flexible duct
The adjacent large flexible duct must retain an open cross-section. Significant crushing increases resistance to airflow.
Neglecting the filter
A dirty filter reduces airflow throughout the system. It should be inspected regularly and replaced according to its actual condition.
Closing several dampers
Closing many grilles can increase static pressure instead of improving distribution to the other rooms.
Ignoring water marks
Any buildup near the drain or base should be inspected promptly, especially during the air-conditioning season.
Our method for an HVAC installation in a complex space
For this Hemmingford project, our work followed a structured sequence:
- inspection of the mechanical room and ducts;
- verification of the available space;
- planning the unit’s orientation;
- return-air adaptation;
- fabrication of the upper transition;
- furnace installation and leveling;
- refrigerant-line connection;
- drainage installation;
- electrical and control connections;
- duct sealing;
- accessibility check;
- operational and airflow testing.
This approach also applies to our installations in Montréal, Laval, Longueuil, on the North Shore and the South Shore, but each building requires a different solution.
In Montréal, we often have to work with narrow basements and old ducts. In Laval, the challenges sometimes involve modifying a more recent central system. In Longueuil and on the South Shore, it is common to integrate a new unit into a mechanical room already occupied by a water heater, air exchanger, or several other systems.
In Hemmingford, the main challenge was the density of the existing installation. We successfully integrated the new ELIOS furnace without unnecessarily removing the entire network, while preserving the necessary access points.
A functional result in a space that left little room for maneuver
The final result features a stable indoor unit connected to the return-air duct through a metal base and linked to the upper ducts by a sealed transition.
The refrigerant lines follow a compact route along the unit. The drainage is grouped near the base, and the main panels remain accessible despite the proximity of the flexible duct and wooden structure.
This installation demonstrates that a furnace replacement cannot be evaluated based solely on the price of the unit. Duct fabrication, drainage, refrigerant-line connections, electrical work, and commissioning represent an essential part of the job.
A properly sized ELIOS Central-Elios electric furnace using R454B can provide efficient heating and cooling. To achieve this, however, it must be integrated precisely into the existing network.
In Hemmingford, we designed the installation around the basement’s actual constraints to achieve an accessible, watertight central system suited to Montérégie winters.