An outdoor unit installed on wall brackets in a particularly narrow side passageway
This ELIOS central heat pump installation in Saint-Valentin illustrates a common situation in properties where available outdoor space is limited. The unit had to be integrated into a narrow side passage between the residence’s foundation wall and the fence separating the two neighboring buildings. A configuration therefore had to be found that would respect airflow, mechanical accessibility, winter protection, and the property’s daily use.
We installed the Central-Elios outdoor unit with R454B refrigerant on two metal wall brackets firmly anchored in the foundation concrete. This method keeps the condenser above the ground, vegetation, and some of the snow accumulation, without taking up additional passageway space.
The photo shows several important features of the project:
- the space between the two buildings is restricted;
- a basement window is located directly near the installation;
- the property has dense vegetation;
- metal structures are stored along the fence;
- the outdoor unit is elevated above ground level;
- the horizontal-discharge fan is oriented toward the open space;
- the compact condenser is positioned parallel to the wall.
In this context, placing the unit on a ground-level pad would have reduced the passageway, exposed the unit to plants, and increased the risk of obstruction during the winter. Wall-mounting was therefore a much better solution for the building.
A central heat pump that requires less floor space
The condenser in the Central-Elios line uses a horizontal-discharge configuration. According to the manufacturer’s documentation, this design can be up to 40% more compact than certain traditional central units with vertical discharge. This feature offers more possibilities when the unit must be installed near a wall, in a side yard, or in an area where every centimeter counts.
In this installation in Saint-Valentin, the condenser's compact format made it possible to maintain a clean configuration despite the presence of numerous obstacles. The front fan remains unobstructed, while the appliance is sufficiently elevated above the ground to limit contact with weeds and debris.
However, this compactness does not mean that the unit can be placed anywhere. Even a horizontal-discharge condenser must maintain the clearances specified by the manufacturer around the heat exchanger, in front of the fan, and near the service panels.
Before securing the brackets, we must verify, among other things:
- the strength of the foundation wall;
- the position of concealed pipes and cables;
- the intended height above the ground;
- the distance between the fan and obstacles;
- access to the refrigerant connections;
- the routing of the lines indoors;
- the ability to carry out maintenance without dismantling the installation.
Why choose wall brackets?
Wall brackets are particularly useful when the ground does not provide a stable base or when circulation space must be preserved.
In this project, they serve several important purposes.
Keep the unit above vegetation
Plants, leaves, and debris can accumulate around a condenser installed too low. When the outdoor heat exchanger is obstructed, the heat pump must run longer to transfer the same amount of heat.
The elevated positioning reduces the risk of grass and plants coming into direct contact with the lower part of the appliance. The owner will still need to keep the area clean, particularly during the summer, but access beneath the unit is significantly easier.
Reduce exposure to snow
In Saint-Valentin, as throughout Greater Montreal, an outdoor unit must be installed with snow and ice accumulation in mind.
In heating mode, the heat pump extracts heat from the outdoor air. Its heat exchanger must therefore remain exposed to sufficient airflow. A unit placed directly on the ground can quickly become surrounded by snow after a storm or after the property has been cleared of snow.
The supports visible in the photo keep the condenser at a useful height above the ground. This elevation helps preserve:
- air intake for the heat exchanger;
- fan clearance;
- water drainage during defrosting;
- access beneath the machine;
- the visibility of the installation for inspections.
Free up the side clearance
In a narrow space, a ground-level base can become a permanent obstacle. It complicates people's movement, yard maintenance, and the transport of objects between the front and back yards.
By securing the unit to the wall, we preserved as much ground-level space as possible. This method is particularly relevant for duplexes, closely spaced houses, and certain properties in Montreal, Laval, Longueuil, the North Shore, and the South Shore, where side clearances are often limited.
An installation designed around the basement window
The presence of a window beneath the unit also required special attention. We had to avoid unnecessarily blocking its opening while maintaining reasonable access to the frame.
The final positioning takes several factors into account:
- the bottom of the unit does not rest on the frame;
- the brackets are anchored into the foundation on each side of the window;
- the weight is not transferred to the frame;
- the fan is not directed toward the glass;
- the unit remains accessible from the front and from the service side.
When a heat pump must be installed near a window, noise, vibrations, and airflow must also be considered. A poorly positioned unit can transmit vibrations to the structure or direct its airflow toward an opening.
The Central-Elios condenser is designed for relatively quiet operation. Depending on the selected capacity, the documentation indicates a nominal outdoor sound level ranging approximately from 60 to 65 dB(A). The brochure also indicates values that vary according to the operating speed, reflecting the system's variable-speed operation.
The quality of the installation nevertheless remains decisive. A quiet unit can become disruptive if the brackets are not properly tightened, if the wall amplifies vibrations, or if the lines come into direct contact with the structure.
Properly anchored metal brackets
Here, the heat pump rests on two triangular metal brackets. This type of support must be selected based on the actual weight of the outdoor unit, not solely on its appearance or dimensions.
The Central-Elios range includes several capacities, from 24,000 to 60,000 BTU/h. According to the manufacturer's technical table, the net weight of the outdoor unit varies from approximately 102 to 243 lb, depending on the model. The choice of brackets, anchors, and spacing must therefore be adapted to the installed capacity.
For this type of project, we pay particular attention to the following points:
- rated strength of the supports;
- depth of the anchors in the concrete;
- condition of the foundation;
- leveling of the unit;
- presence of vibration-damping elements;
- alignment of the two arms;
- clearance between the condenser and the cladding;
- corrosion protection.
A wall-mounted installation must never rely on vinyl siding. The anchors must reach a sufficiently solid structure to support the weight of the heat pump and the forces produced by vibrations, wind, and operating cycles.
Technical specifications of the Central-Elios system using R454B
A range designed for cold climates
The Central-Elios central heat pump is designed to operate in heating mode down to an outdoor temperature of -30 °C. The documentation indicates that it can maintain 69% to 76% of its rated capacity at this temperature, depending on the model and operating conditions.
The manufacturer also states that the system can reach 100% of its rated capacity at -20 °C. This information is particularly relevant for homeowners looking for a central heat pump for cold climates in Quebec.
This does not necessarily mean that a supplemental system is unnecessary. The required capacity still depends on:
- building area;
- level of insulation;
- number of windows;
- air infiltration;
- duct distribution;
- design temperature;
- actual heating needs.
The range can be combined with electric supplemental heating elements from 3 to 25 kW, depending on the configuration. These can support the heat pump during periods of high demand or serve as auxiliary heating.
Inverter technology and modulating operation
The Inverter compressor adjusts its speed according to the building’s demand. Instead of operating only at full capacity before shutting down completely, it can modulate its output to maintain a more stable temperature.
This modulation can help:
- reduce temperature fluctuations;
- limit abrupt starts;
- improve comfort between cycles;
- reduce consumption when demand is low;
- reduce noise during part of the operation;
- maintain more consistent heat production.
In a home equipped with a properly sized duct network, this technology provides uniform heating and cooling distribution across multiple rooms.
However, the thermostat and controller must be compatible with the system. The documentation specifically mentions the ST1S42RW1 touchscreen thermostat, which is Wi-Fi compatible, as well as the KJRSAALW1 controller, also available with Wi-Fi compatibility.
A new-generation R454B refrigerant
This heat pump uses R454B, a refrigerant used in several new generations of HVAC equipment. It is classified as A2L, meaning that it has low flammability and requires adapted installation methods.
The Central-Elios system includes a leak-detection mechanism. According to the manufacturer, the sensor monitors for the possible presence of refrigerant and, if detected, may stop the compressor, maintain airflow, and transmit a service alert.
For technicians, using R454B notably involves:
- approved tools for A2L refrigerants;
- a rigorous leak-testing procedure;
- adequate ventilation during the work;
- careful handling of the circuit;
- compliance with the manufacturer’s requirements;
- documented commissioning.
The installation of an R454B system must therefore not be treated as a simple like-for-like replacement of an older R410A heat pump.
Energy performance varies according to capacity
The Central-Elios product line includes systems ranging from:
- 24,000 BTU/h;
- 30,000 BTU/h;
- 36,000 BTU/h;
- 48,000 BTU/h;
- 60,000 BTU/h.
Cooling efficiency reaches up to 18.3 SEER2, while seasonal heating efficiency can reach 8.6 HSPF2 in Region V, depending on the selected combination.
The models are identified in the technical brochure as meeting ENERGY STAR 6.1 and ENERGY STAR Cold Climate requirements. This certification may be relevant when assessing certain financial incentives, but actual subsidy eligibility must always be confirmed using the exact indoor-outdoor combination number, the current program criteria, and the building’s file.
It would therefore be inaccurate to automatically promise a subsidy solely because the brand and refrigerant are known.
Piping to be verified before installation
The technical table for the product line specifies refrigerant piping of:
- 3/8 in on the liquid side;
- 3/4 in on the gas side.
The maximum permitted length varies according to capacity. It can reach 164 ft for 24,000 and 30,000 BTU systems, and 246 ft for capacities from 36,000 to 60,000 BTU.
The maximum height difference, meanwhile, ranges from 82 to 98.4 ft depending on the model.
These values show why it is essential to check the existing lines before a replacement. Older piping is not necessarily compatible with the new heat pump.
We must confirm:
- the internal diameter;
- the total length;
- the elevation difference;
- the condition of the insulation;
- the cleanliness of the circuit;
- the absence of damage;
- the additional amount of refrigerant required.
Automatically reusing the lines without performing these checks can compromise the compressor’s performance and durability.
Airflow to preserve around the condenser
In the photo, the main fan is directed toward the open passageway. This orientation is important. Exhaust air must not immediately strike a wall or flow directly back toward the heat exchanger.
Even when the installation meets clearance requirements at the time of the work, the surroundings may change. Vegetation may grow, objects may be stored in front of the unit, or temporary structures may be added.
In this case, the metal frames stored along the fence must never be moved in front of the fan. The area directly in front of the unit must remain clear.
The owner should also:
- regularly trim the plants around the bracket;
- remove leaves accumulated behind the unit;
- avoid placing objects against the condenser;
- monitor snow accumulation in front of the fan;
- check that no substantial ice forms beneath the unit;
- keep the service panels accessible.
The importance of defrosting in winter
In heating mode, the outdoor heat exchanger becomes cold and may accumulate frost. The heat pump then initiates a defrost cycle. During this process, water drains beneath the unit.
Installing the unit on wall brackets provides useful clearance for this water, but the area beneath the unit must remain clear. A significant accumulation of ice could eventually reach the base of the condenser or place pressure on the brackets.
Ice should not be removed with a hammer, metal shovel, or boiling water. These methods can damage:
- the heat exchanger fins;
- the lower tray;
- the wiring;
- the foundation;
- refrigerant lines.
When abnormal accumulation appears, its cause should be determined instead. It may be related to insufficient drainage, an obstruction, a defrosting problem, or simply exceptional weather conditions.
The most costly mistakes in a narrow side yard
A similar installation requires more preparation than a project carried out in a large, unobstructed yard.
Among the mistakes to avoid are:
Installing the condenser too close to the ground
This mistake increases exposure to snow, vegetation, and debris.
Pointing the fan toward a fence that is too close
The discharged air can rebound toward the unit, hindering heat exchange.
Underestimating the unit’s weight
The brackets and anchors must be selected according to the exact model.
Fastening the unit only to the cladding
The exterior cladding is not a sufficient load-bearing structure.
Blocking a window
The installation must take access, light, and use of the opening into account.
Neglecting vibrations
The metal brackets, fasteners, and lines must be installed in a way that minimizes vibration transmission to the building.
Letting vegetation overgrow the unit
Even a perfectly executed installation can lose efficiency if the area is not maintained.
An installation adapted to the building’s realities
This ELIOS Central-Elios central heat pump installation in Saint-Valentin is not simply a matter of fastening an outdoor unit to a wall. It results from an analysis of the space, foundation, window, terrain, and maintenance requirements.
The elevated positioning helps protect the condenser from some ground-level accumulation. Wall brackets clear the passage and keep the unit above the vegetation. The horizontal discharge is directed toward the open space, while the machine’s compact design makes it easier to integrate between the two buildings.
At AirGreen, we apply the same level of care to every HVAC installation in Montreal, Laval, Longueuil, on the North Shore, and on the South Shore. We do not choose the location solely based on the shortest distance. We consider airflow, noise, vibrations, defrosting, future servicing, and building protection.
A high-performance central heat pump must be supported by an equally rigorous installation. This combination provides consistent comfort, uniform air distribution, and reliable operation during Quebec winters.