A compact central installation completed with precision on a brick façade
At Mont-Saint-Grégoire, we recently completed the installation of an ELIOS central heat pump operating with R454B refrigerant. The project perfectly illustrates a common challenge in Montérégie residences: integrating new heating and cooling equipment into a limited outdoor space while ensuring adequate airflow, a solid mechanical installation, and convenient access for future maintenance.
On this property, the available space was located between two sections of the building, against a foundation wall topped with a brick façade. The outdoor unit therefore had to be positioned carefully to avoid blocking the passageway, maintain the necessary clearances around the unit, and protect the system from ground moisture, snow, and plant debris.
Our AirGreen team chose a wall-mounted installation using metal brackets. This configuration keeps the central heat pump elevated, stable, and well clear of the ground, while making efficient use of the space available around the residence.
Why install the outdoor unit on wall brackets?
In this project in Mont-Saint-Grégoire, the ground beneath the unit’s location consisted of an area of soil and vegetation near the foundation. A ground-level installation would have required creating a level base, with a slab or suitable support, and preparing the ground to limit movement caused by freezing and thawing.
Wall brackets were a particularly suitable solution in this case. The outdoor unit was mounted on two sturdy metal brackets anchored to the foundation. This method offers several concrete advantages:
- it keeps the unit away from soil, mud, and water accumulation;
- it reduces the risk of clogging caused by leaves and weeds;
- it facilitates the drainage of water produced during defrost cycles;
- it limits snow accumulation directly around the base;
- it simplifies access to certain components during HVAC maintenance;
- it preserves more ground space around the building.
The choice and positioning of the anchors are essential. A central outdoor unit generates normal vibrations during operation. The supports must therefore be securely installed in a structure capable of bearing the appliance's load, rather than simply in fragile exterior cladding.
For this installation, the brackets were secured to the concrete section of the foundation. The unit was then placed on vibration-isolating feet to limit vibration transmission to the building structure.
An ELIOS heat pump designed for central heating and cooling
The installed ELIOS R454B central heat pump is connected to the home's indoor system to distribute heating and cooling through the existing duct network or one adapted to the project.
Unlike a wall-mounted heat pump, which primarily conditions an open area from a wall-mounted indoor unit, a central heat pump distributes conditioned air throughout several rooms. It is particularly suitable for homes already equipped with ventilation ducts or for projects where uniform distribution is a priority.
A properly sized central installation can notably improve:
- temperature stability between floors and different rooms;
- air circulation throughout the home;
- humidity management during warm periods;
- winter comfort when integrated into an appropriate heating strategy;
- air filtration, depending on the type of indoor component and filter used.
However, final performance depends not only on the outdoor unit. The selected capacity, duct configuration, airflow, ventilation settings, network airtightness, and quality of commissioning all play a decisive role.
R454B refrigerant: a new generation of HVAC systems
This heat pump uses R454B refrigerant, now found in several new generations of heating and cooling equipment.
The arrival of R454B entails certain adaptations to technicians’ work methods. The installation must comply with the manufacturer’s requirements regarding refrigeration piping, connections, evacuation procedures, leak testing, and commissioning.
R454B belongs to a category of mildly flammable refrigerants. This does not mean that a properly installed unit presents any particular danger to occupants. Rather, it means that technicians must use tools, procedures, and practices compatible with this type of refrigerant.
At AirGreen, we pay particular attention to the following elements when installing an R454B heat pump:
- compliance of the refrigeration lines;
- the cleanliness of the inside of the piping;
- the quality of the connections;
- the leak test;
- performing a deep vacuum before commissioning;
- verification of the charge according to the actual piping length;
- compliance with the instructions specific to the installed model;
- clear identification of the equipment for future service work.
Poor piping preparation can introduce moisture or contaminants into the refrigeration circuit. Over time, this can affect the compressor, valves, and performance stability. Installation quality therefore remains just as important as the choice of brand.
A carefully considered placement despite limited space
The project photograph shows that the outdoor unit was placed in a relatively narrow section between a brick wall and an adjacent façade covered with siding.
In such a location, we must analyze several factors before securing the equipment:
Air circulation
The outdoor fan must be able to draw in and discharge air without encountering excessive obstruction. A heat pump installed too close to a wall, fence, balcony, or another appliance may draw back in the air it has just discharged.
This recirculation can reduce performance, lengthen cycle times, and place unnecessary strain on the compressor. We therefore comply with the clearances specified by the manufacturer and orient the fan side toward an open area.
In this project, the front of the unit remains unobstructed, promoting good air discharge.
Proximity to the service panel
An outdoor service disconnect is visible near the unit. This component makes it possible to isolate the heat pump’s power supply during maintenance or technical work.
Its location must remain accessible. It must not be concealed behind the unit, buried under vegetation, or placed in a difficult-to-reach position.
Routing the lines
The refrigerant lines and wiring were grouped together and routed compactly toward the building. A clean finish is not merely a matter of appearance. It also protects the components from impacts, prolonged exposure to the elements, and accidental damage.
We avoid unnecessary loops, crushed lines, and excessively tight bends. Each change in direction must preserve the pipe’s internal diameter to maintain adequate refrigerant flow.
Defrost water
In heating mode, an outdoor heat pump can accumulate frost on its coil. The system then initiates a defrost cycle. The resulting water must be able to drain away without creating an accumulation of ice beneath the unit.
The elevation provided by wall brackets creates more space beneath the unit and reduces the risk of ice reaching the base of the heat pump. However, the owner must keep this area clear during the winter.
The essential steps of this HVAC installation
A central HVAC installation involves much more than attaching the visible outdoor unit. Our work follows a methodical sequence to protect the new equipment and ensure its operation.
Sizing validation
We first assess the home’s needs, the ductwork configuration, the capacity of the indoor component, and the characteristics of the existing installation.
An oversized heat pump can quickly reach the requested temperature without running long enough to provide good dehumidification. An undersized system, on the other hand, may run continuously during peak periods without maintaining the desired comfort level.
The calculation must take into account the floor area, insulation, windows, building orientation, air infiltration, and room layout.
Preparing the outdoor location
We then determine the unit’s height, the position of the supports, and the route of the lines. The anchor points are selected according to the available structure.
At the Mont-Saint-Grégoire property, installing the unit above the foundation helps maintain a useful distance from the ground and vegetation.
Refrigeration installation
The lines connecting the outdoor unit to the indoor component must be installed without contamination and adequately protected. The line insulation must remain continuous to prevent condensation and performance losses.
A leak test is performed before evacuation. This step helps identify a potential leak before refrigerant is introduced into the entire circuit.
Electrical connection
The electrical circuit must be sized according to the values indicated on the equipment nameplate and applicable requirements. The circuit breaker, wiring, and disconnect switch are not selected solely based on the BTU capacity.
Each model has specific electrical ratings that must be respected. An oversized protective device or improper wiring can compromise the installation's safety and compliance.
Commissioning and checks
After the connection, we check operation in cooling and heating modes, thermostat response, air temperatures, static pressure, airflow, and the system's overall performance.
We also ensure that the outdoor unit remains stable and that no abnormal vibrations are transmitted to the foundation.
What homeowners in Mont-Saint-Grégoire can take away from this project
Avoid choosing the location based solely on appearance
A discreet outdoor unit enclosed in a corner without airflow may operate less efficiently than a slightly more visible unit installed under proper conditions.
The location should be determined based on technical clearances, the route of the lines, electrical access, noise, water drainage, and maintenance needs.
Do not let vegetation overtake the heat pump
The visible area beneath the unit contains soil and some vegetation. These must be controlled so they do not reach the coil or block the space around the equipment.
We recommend keeping the area clean and unobstructed. Leaves, branches, and weeds can reduce airflow and trap moisture against certain components.
Never completely cover the unit in winter
A central heat pump must continue exchanging air while operating in heating mode. A closed cover or makeshift structure can block the fan and damage the equipment.
It is best to carefully remove significant snow accumulation around the unit, without striking the fins or using tools that could puncture the heat exchanger.
Schedule regular HVAC maintenance
Even a new installation requires follow-up. Indoor filters should be inspected and replaced according to their condition. The outdoor unit should remain clean, and the ducts, condensate drain, and ventilation system should be checked periodically.
Insufficient airflow caused by a clogged filter can reduce comfort and impair system operation. Preventive maintenance also makes it possible to detect vibration, unusual noise, an obstruction, or a drainage problem sooner.
A project representative of our approach at AirGreen
This ELIOS R454B central heat pump installation in Mont-Saint-Grégoire demonstrates the importance of adapting each project to the building's actual configuration.
We do not install an outdoor unit using the same method on every property. A home in Montreal may require installation on a balcony or in a narrow yard. In Laval, the presence of a side passage may influence the unit's orientation. In Longueuil or on the South Shore, a clear foundation may favor the use of wall brackets. On the North Shore, managing snow and prevailing winds may become a priority.
In every case, we aim to combine:
- positioning that complies with the manufacturer's requirements;
- efficient airflow;
- durable mechanical fastening;
- a clean, protected line set route;
- easy access for servicing;
- careful integration outside the building;
- complete commissioning.
The result achieved in Mont-Saint-Grégoire is compact, functional, and adapted to the existing structure. The ELIOS unit is securely elevated, its fan remains unobstructed, the electrical disconnect remains accessible, and the connections are grouped near the building.
For a homeowner comparing several options for central heating, air conditioning, or replacing an older system, this project highlights an essential rule: the brand and capacity of the equipment matter, but installation quality largely determines its reliability, efficiency, and lifespan.