An outdoor unit installed high beneath a metal staircase to clear the passage and protect the heat pump
For this project carried out in Saint-Léonard, our AirGreen team had to integrate a Samsung WindFree™ MaxHeat wall-mounted heat pump into a very particular outdoor space: a narrow side passage bordered by a brick wall and partially covered by a metal staircase.
The outdoor unit could not simply be placed on the ground. Such a configuration would have reduced the passage width, complicated the movement of the wheeled bins, and exposed the equipment more to snow, leaves, runoff water, and accidental impacts.
We therefore installed the heat pump on a sturdy aluminum wall bracket, secured to the masonry and reinforced with diagonal supports. This solution completely clears the ground while positioning the unit at a height favorable for winter operation.
The photograph shows the side of the Samsung outdoor unit, its heat exchanger protected by a grille, the lines leading to the brick wall, and the metal structure built to support the machine. The installation appears simple once completed, but it required careful analysis of the masonry, vibrations, clearances, snow, drainage, and future access for maintenance.
Why a wall-mounted installation was preferable to a ground installation
The outdoor passage visible in the photo is used to move between the front and back of the building. It also contains collection bins and a fire escape or access stairs to the upper floors.
Placing the unit directly on a slab or on a low support would have created several drawbacks:
- reduced usable passage width;
- risk of collision with wheeled bins;
- snow accumulation around the heat pump;
- increased exposure to debris and water;
- more difficult access beneath the stairs;
- the possibility of the unit being moved or struck;
- ice formation around the base during defrost cycles.
The wall bracket, on the other hand, keeps the Samsung heat pump above these obstacles. The ground remains clear, making cleaning, movement, and everyday use of the outdoor space easier.
This solution is particularly useful in the duplexes, triplexes, and residential buildings of Saint-Léonard, where side yards can be narrow and shared by multiple occupants.
An aluminum structure suited to the weight and vibrations of the unit
The outdoor unit rests on two horizontal rails supported by a triangulated structure. The diagonal arms transfer part of the load to the wall and increase the rigidity of the assembly.
A heat pump must never be installed on an improvised or inadequately sized bracket. Its static weight is only one element of the calculation. The following must also be taken into account:
- compressor vibrations;
- variations in fan speed;
- loads caused by snow or ice;
- wind;
- freeze-thaw cycles;
- the stresses exerted on the anchors;
- the possible additional weight during servicing.
The structure must remain stable throughout the equipment’s service life. A support that bends or deforms can alter the machine’s level, transmit vibrations to the building, and place unwanted stress on the refrigerant connections.
In this project, the triangulated configuration helps distribute the load while leaving clear space beneath the unit.
Mounting to a brick wall requires an appropriate method
The presence of a brick wall does not automatically mean that any load can be attached to it anywhere.
Before installation, we must check the type of masonry, the condition of the joints, the position of the anchors, and the constraints associated with the building. The mounting must be carried out using anchors suited to the material and the weight of the equipment.
An inadequate mounting can lead to:
- progressive loosening of the bolts;
- cracks in the brickwork;
- deformation of the bracket;
- structural noise;
- movement of the unit;
- a risk to occupants walking beneath the installation.
We must also avoid placing the anchors too close to an edge, a weakened joint, or an area that is already damaged.
The installation of a wall-mounted heat pump in Saint-Léonard must therefore be designed as a complete assembly: machine, support, isolators, anchors, wall, lines, and clearances.
The role of the antivibration isolators installed beneath the heat pump
Antivibration blocks installed between the Samsung cabinet and the metal rails can be seen beneath the unit.
These isolators reduce the direct transmission of vibrations to the bracket and brick wall. They are particularly important when the unit is attached to the structure of an occupied building.
Even a modern variable-speed heat pump produces slight vibrations when the compressor starts, speeds up, or slows down. Without mechanical decoupling, these vibrations can travel through the masonry and become audible indoors.
A discreet outdoor noise can then turn into a hum in a bedroom or living room, especially at night.
The isolators help to:
- reduce structural vibrations;
- limit noise transmitted to the wall;
- protect the mounting points;
- improve the stability of the unit;
- reduce mechanical stress on the bracket.
Their effectiveness depends on their quality, position, and how they are compressed under the weight of the unit.
Installing a heat pump under a staircase: clearances to check
The metal staircase above the unit created an additional constraint. The heat pump had to be high enough to clear the ground, but not so high that it interfered with the steps and the upper structure.
We had to maintain sufficient space around the unit to allow for:
- the intake of air through the heat exchanger;
- the discharge of air through the front fan;
- access to the service panels;
- the cleaning of the outdoor coil;
- the connection of the lines;
- the future removal of components;
- the drainage of defrost water.
A unit positioned too close to a step, wall, or other obstacle may draw back in some of the air it has just expelled. This recirculation reduces efficiency and increases operating time.
In summer, the unit may draw in warmer air. In winter, it may draw in colder, more humid air, which promotes frost formation and increases the frequency of defrost cycles.
The position shown in the photo allows the unit to benefit from the open passage while remaining protected beneath the structure.
The protection provided by the staircase without enclosing the unit
The staircase provides some protection from direct precipitation and snowfall from above. This protection can be beneficial, provided that the space is not enclosed.
A heat pump must never be enclosed in an airtight cabinet or surrounded by panels that prevent air circulation. It must exchange a large amount of air with the outdoors to transfer heat.
In the Saint-Léonard project, the open-grating steps and open sides allow air to circulate. The unit therefore benefits from partial protection without being enclosed.
However, you must periodically check that no objects are stored in front of or around the unit. Rolling bins, construction materials, patio furniture, and bags can quickly reduce clearances if the area is not monitored.
A Samsung WindFree™ MaxHeat suited to Montreal winters
The Samsung WindFree™ MaxHeat range is designed to provide heating and cooling in regions exposed to low temperatures.
Depending on the exact combination of units and the selected capacity, certain models in this series can continue operating in heating mode down to approximately -30 °C.
For Saint-Léonard residents, this performance makes it possible to use the heat pump for much of the winter rather than only during the mild periods of fall and spring.
For certain 12,000 BTU configurations, the range can reach approximately 24 SEER2, particularly with a combination associated with reference AHRI 215399291. However, the specifications must always be confirmed using the exact indoor and outdoor unit numbers.
A commercial name such as WindFree™ MaxHeat may encompass several capacities. Performance, electrical consumption, low-temperature heating capacity, and eligibility for financial incentives may therefore vary.
WindFree™ technology to reduce indoor drafts
The system's distinctive advantage is also found in the indoor unit. Once the desired temperature is reached, WindFree™ technology can diffuse air through numerous micro-openings located on the front panel.
This method reduces the sensation of a continuous stream of cold air directed toward the occupants.
It is particularly suitable for units installed:
- in a bedroom;
- above a sofa;
- in a work area;
- facing a table;
- in a space where occupants remain for long periods;
When rapid cooling is needed, the unit can use its main louver. It can then maintain the temperature with gentler air distribution.
Comfort still depends on the placement of the indoor unit, sizing, and air circulation between rooms. WindFree™ technology improves air distribution, but it cannot correct for a unit installed in the wrong location.
The system capacity must match the building
The capacity of a wall-mounted heat pump should not be chosen solely based on the total floor area.
In Saint-Léonard, several buildings have particular layouts: stacked dwellings, interior staircases, shared walls, additions, finished basements, and enclosed rooms.
We assess, in particular:
- insulation;
- windows;
- the number of exposed walls;
- solar orientation;
- ceiling height;
- the layout of the rooms;
- air circulation;
- air infiltration;
- the floor where the dwelling is located;
- low-temperature heating requirements.
An oversized unit may run in short cycles, control humidity less effectively, and create temperature fluctuations. An undersized unit may run continuously without reaching the setpoint during very hot or very cold periods.
A building-specific calculation provides more stable operation and greater comfort.
Protected connections and commissioning that determine system reliability
Routing the lines near the brick wall
The refrigerant lines and wiring enter the building behind the unit. Their route must be flexible enough to absorb slight movements, but adequately supported so they do not vibrate or rub against the masonry.
The lines generally include:
- two insulated copper pipes;
- a communication cable;
- the power supply according to the configuration;
- a condensate drain from the indoor unit.
The pipe insulation must be protected against UV rays, moisture, and mechanical damage. Deteriorated insulation reduces performance and can lead to condensation.
The opening in the wall must also be sealed to prevent air, water, and insect infiltration.
The slope of the indoor drain
In cooling mode, the indoor unit removes moisture from the air. This water must be drained through a drain installed with a sufficient slope.
An improper slope can cause:
- water accumulation;
- gurgling noises;
- a leak on the wall;
- odors;
- overflowing of the pan;
- damage to the interior finish.
When gravity drainage is not possible, a condensate pump may be necessary. However, we favor natural drainage when the building configuration allows it, because this solution has fewer mechanical components and produces less noise.
Evacuation before opening the valves
Once the lines are connected, the circuit must be evacuated. This step removes the air and moisture present in the pipes.
Moisture left in a refrigeration circuit can react with the compressor oil, form contaminants, and reduce the system’s service life.
Evacuation must not be replaced by a quick refrigerant purge. An installation may appear to operate normally on the first day while having been contaminated during commissioning.
Our technicians check the vacuum behavior and ensure that the circuit is ready before releasing the charge specified by the manufacturer.
Leak testing of the connections
Flared connections must be formed and tightened precisely.
Insufficient tightening can cause a progressive leak. Overtightening can crack the copper or deform the flare.
A slow leak often causes gradual symptoms:
- loss of capacity;
- extended operation;
- frost formation;
- insufficient discharge air temperature;
- error codes;
- compressor overheating.
During commissioning, we check the connections and confirm that the system is operating according to the conditions observed.
The electrical supply must match the nameplate.
The heat pump power supply must be designed according to the exact specifications of the outdoor unit.
The following requirements must be met:
- voltage;
- minimum circuit ampacity;
- maximum protection;
- the conductor gauge;
- the type of circuit breaker;
- grounding requirements;
- the presence of an accessible disconnect switch.
Two heat pumps with the same nominal capacity in BTUs may require different circuits. We therefore never select the circuit breaker based solely on the number of BTUs.
Drainage of defrost water beneath a wall-mounted unit
In heating mode, the outdoor heat exchanger naturally accumulates frost. The system then activates a defrost cycle that melts this buildup.
The water produced must be able to fall and drain beneath the unit. Wall mounting facilitates this drainage, since the unit is well clear of the ground.
However, it remains important to consider what is located below. Water must not create a dangerous sheet of ice in a passageway.
In this installation, the unit is positioned above a side area where winter accumulation can be monitored and managed.
The owner should avoid storing objects directly beneath the heat pump, as they could block drainage or be damaged by water.
Best practices during winter
To maintain adequate performance, we recommend:
- keep the area in front of the heat pump clear;
- remove snow accumulated around the passage;
- do not push snow against the heat exchanger;
- monitor ice formation beneath the unit;
- avoid completely covering the unit;
- do not use a metal tool on the fins;
- never pour boiling water on the cabinet.
A light accumulation of frost is normal. During defrosting, the outdoor fan may stop and steam may appear. This does not necessarily indicate a malfunction.
However, a layer of ice that persists and blocks the heat exchanger must be inspected by a technician.
Maintaining the heat exchanger in a side passage
The proximity of trees, the ground, and wheeled bins can promote the accumulation of dust, pollen, and debris on the heat exchanger.
A clogged heat exchanger reduces airflow and forces the compressor to run longer.
During a professional HVAC maintenance service, we can, among other things:
- clean the fins;
- check the connections;
- inspect the lines;
- check for vibrations;
- tighten accessible components;
- inspect the drainage;
- test the operation of the modes;
- check the overall condition of the wall bracket.
Cleaning must be carried out without bending the fins. A pressure washer used too close to the coil can damage the heat exchanger.
Mistakes to avoid when installing an outdoor wall-mounted unit
This installation in Saint-Léonard illustrates several common mistakes:
- Using a bracket that is too light for the weight of the appliance.
- Fastening the supports to weakened masonry or using inadequate anchors.
- Forgetting vibration isolators between the machine and the metal.
- Placing the unit too close to the staircase, restricting airflow.
- Installing the valves in an inaccessible area for repairs.
- Leaving the lines unprotected from sunlight and impacts.
- Neglecting defrost water, which can form a sheet of ice.
- Storing objects in front of the fan after installation.
- Failing to plan access for cleaning the heat exchanger.
- Choosing the capacity solely according to the stated area.
The project’s success depends just as much on these details as on the equipment brand.
Possible eligibility for subsidy programs
Certain Samsung WindFree™ MaxHeat combinations may qualify for financial assistance programs available in Quebec.
Eligibility must be verified based on:
- the complete unit numbers;
- the AHRI reference;
- low-temperature capacity;
- cold-climate certification;
- the type of building;
- the purchase date;
- the installation date;
- the rules in effect at the time of the application.
The series name does not automatically guarantee a subsidy.
We recommend keeping the detailed invoice, proof of payment, serial numbers, photos of the rating plates, and installation-related documentation.
The final result for this Saint-Léonard residence
The Samsung WindFree™ MaxHeat wall-mounted heat pump is now installed above ground, firmly supported by a bracket designed for the location.
This solution provides several concrete benefits:
- clear exterior passage;
- increased protection from snow;
- reduced risk of impact with wheeled bins;
- improved drainage of defrost water;
- reasonable access for maintenance;
- mechanical stability;
- reduced vibrations thanks to isolators;
- efficient use of an otherwise difficult-to-use space.
The project demonstrates that a narrow space beneath a staircase is not necessarily an obstacle to a high-quality installation. However, the structure, clearances, and winter operation must be assessed before choosing the location.
At AirGreen, we carry out wall-mounted heat pump installations in Saint-Léonard, throughout Montreal, as well as in Laval, Longueuil, on the North Shore, and on the South Shore. Each installation is adapted to the building’s architecture, site constraints, and occupants’ comfort needs.