Two independent systems precisely installed on a façade with limited space
This installation completed by our team in Dollard-des-Ormeaux, in western Montréal, perfectly illustrates a common challenge in multi-unit properties and homes with several comfort zones: how can two wall-mounted heat pumps be installed without cluttering the property, obstructing the windows, or hindering access around the building?
The chosen solution was to install two SAMSUNG WindFree™ MaxHeat wall-mounted heat pumps, each with its own outdoor unit. Both units were mounted on the wall using sturdy metal brackets at a carefully determined height. This configuration completely frees up the ground while protecting the units from snow, standing water, leaves, and debris.
On this brick property, the available space was limited by several elements: a ground-floor window, a basement window, a vertical structural downspout, the narrow passage between the buildings, and the routes required for the refrigerant lines. Our team therefore had to consider the anchoring strength, airflow, future accessibility for maintenance, and the installation’s overall appearance simultaneously.
The result is a compact, orderly, and functional HVAC installation, designed to provide efficient heating during Quebec winters and comfortable cooling during hot and humid periods.
Why install two SAMSUNG heat pumps instead of a single unit?
In a property divided into several spaces, floors, or units, a single wall-mounted system does not always distribute temperature evenly. The heat produced by one indoor unit has difficulty circulating behind closed doors, in remote rooms, or between separate levels.
Installing two independent systems offers several advantages:
- a separately adjustable temperature in each zone;
- better distribution of heating and cooling;
- less reliance on electric baseboard heaters;
- the ability to operate only the occupied zone;
- comfort better suited to the habits of each occupant;
- some redundancy in the event that one of the systems requires servicing.
In this project in Dollard-des-Ormeaux, the two outdoor units were neither stacked nor installed directly on the ground. They were placed side by side, with sufficient clearance to allow each one to intake and discharge air properly.
This distinction is important. A heat pump that lacks sufficient space around its heat exchanger may recycle its own air, work unnecessarily harder, and lose some of its efficiency. When several units are installed on the same façade, their positioning must therefore be planned as a whole rather than as two separate installations.
SAMSUNG WindFree™ technology for more uniform comfort
The SAMSUNG WindFree™ MaxHeat range is designed to provide heating and cooling from the same system. In cooling mode, WindFree™ technology is intended to reduce the unpleasant sensation of a cold draft blowing constantly toward occupants.
After lowering the room temperature, the indoor unit can distribute air more gently through numerous micro-openings. This gradual distribution is particularly appreciated in a bedroom, living room, home office, or any room where occupants remain seated for long periods.
In heating mode, a heat pump extracts energy from the outdoor air and transfers it indoors. Even when the outdoor temperature drops below freezing, the air still contains usable thermal energy. The modulating compressor then adjusts its output to the building’s actual needs.
Unlike a unit that operates only at full power before shutting off abruptly, an inverter heat pump can gradually reduce its output as the requested temperature is nearly reached. This modulation promotes:
- a more stable indoor temperature;
- less abrupt cycles;
- generally quieter operation;
- better management of electricity consumption;
- reduced comfort fluctuations.
The exact capacity, seasonal performance, and eligibility for financial assistance nevertheless depend on the precise combination of indoor and outdoor model numbers. This information must always be confirmed using the technical data sheet and the recognized reference number at the time of purchase.
Wall brackets suitable for a masonry façade
Choosing the right supports was an essential part of this wall-mounted heat pump installation in Montreal. An outdoor unit contains a compressor, fan, heat exchanger, and several mechanical components. Its weight, along with the vibrations produced during operation, must be supported by a suitable structure.
Our technicians installed each unit on its own individual metal wall bracket. The brackets were positioned so that:
- distribute the weight properly;
- keep the units perfectly level;
- maintain space beneath each unit;
- avoid obstructing the windows;
- facilitate the drainage of defrost water;
- keep the service panels accessible;
- preserve clearance between the two pieces of equipment.
Attachment points on a brick façade must be selected carefully. Installation does not simply involve drilling into the masonry and hanging the unit. We assess the wall type, the condition of the materials, the position of the openings, and the anchors’ capacity to support the expected loads.
Vibration isolators are also visible beneath the units. These components help limit the transmission of mechanical vibrations to the supports and the building structure.
A height selected to withstand snow and defrosting
Installing an outdoor unit directly on the ground may seem simpler, but this method is not always suitable for the Greater Montreal climate. In winter, snow can quickly accumulate around the coil. Water produced during defrost cycles can also freeze beneath the unit and form a mass of ice.
By securing both units at a safe height, we maintained significant clearance beneath the equipment. This decision helps protect:
- the side and rear air intakes;
- the lower part of the coil;
- the drainage points;
- the lines and connections;
- the access required for seasonal cleaning.
Defrosting is a normal function of a heat pump in winter. When outdoor moisture freezes on the coil, the system temporarily reverses its cycle to melt the buildup. The resulting water must then be able to drain freely.
A common mistake is installing the unit too close to the ground or above a surface where water cannot drain. Ice can then rise toward the base of the unit. An appropriate height significantly reduces this risk, although occasional inspection is still recommended during periods of freezing temperatures and heavy snowfall.
A piping route planned around the openings
The lines connecting each indoor unit to its outdoor unit typically include insulated refrigerant pipes, communication wiring, and the required power supply according to the electrical configuration. Condensate drainage must also maintain an appropriate slope when operating by gravity.
In this project, the routes had to go around the windows and integrate with the façade’s distinctive geometry. We planned the exits to avoid:
- excessively tight bends;
- unnecessarily exposed lines;
- areas likely to retain water;
- conflicts with window frames;
- an improperly sealed wall penetration;
- difficult access to the technical connections.
The diameter of the lines must never be chosen solely based on the appearance of the unit. It must exactly meet the manufacturer’s requirements for the installed combination. Incorrect piping dimensions can disrupt oil return, alter refrigerant velocity, and affect compressor reliability.
After the connection, a professional installation includes, among other things, a leak test, proper evacuation, and an operational check. These steps are not visible in the final photograph, but they play a decisive role in the system’s durability.
Maintenance access was preserved
The available space in front of the two units is relatively narrow. The presence of a ladder in the photo also shows that the work at height had to be organized precisely.
Despite these constraints, the units were positioned so that the following remained accessible:
- the electrical panels;
- the service valves;
- the refrigerant connections;
- the filters and outdoor heat exchangers;
- the fastening points;
- the areas requiring inspection.
This accessibility is too often overlooked. A unit may appear to be perfectly installed on the day of the work, but become very costly to service if a wall, fence, balcony, or second unit later prevents its panel from being opened.
At AirGreen, we therefore also plan for the years following installation. A technician must be able to perform diagnostics, check pressures when required, clean the heat exchanger, and replace a component without having to dismantle the neighboring unit.
This Dollard-des-Ormeaux project reveals the details that distinguish a durable installation
The mistakes we avoid when installing two units
Installing multiple heat pumps on the same façade requires more rigorous coordination than installing a single unit. The most common errors include:
Units installed too close to each other
Insufficient space can reduce airflow, complicate cleaning, and make certain panels impossible to remove.
Fastening only into fragile materials
Loads must not rest on inadequate cladding or deteriorated masonry. The type of anchor must match the actual substrate.
Insufficient height
An unit placed too low becomes vulnerable to blowing snow, ice buildup, and debris.
Unprotected lines
Insulation exposed to UV rays, animals, and impacts deteriorates more quickly. A well-planned protective finish improves durability and appearance.
A capacity selected solely according to floor area
Floor area is only a starting point. Insulation, sun exposure, the number of windows, ceiling height, air infiltration, and room layout also affect the thermal load.
Hydro-Québec also recommends verifying the model’s eligibility, accurately assessing its capacity, taking the building envelope into account, and paying attention to the sound level before purchasing.
A properly sized heat pump is more important than an oversized unit
A larger heat pump is not automatically better. In cooling mode, an oversized unit may reach the requested temperature too quickly and reduce its operating time. It then has less time to remove moisture from the air.
Conversely, an undersized system may run continuously without fully meeting needs during extreme temperatures.
To determine the appropriate configuration, we consider, among other factors:
- the area actually served;
- the layout of the rooms;
- the quality of the insulation;
- the number of levels;
- the building’s orientation;
- the windows;
- the presence of doors between zones;
- the existing heating system;
- the electrical panel constraints.
In certain buildings in Dollard-des-Ormeaux, Montreal, Laval, Longueuil, the North Shore, or the South Shore, two moderately sized heat pumps provide better results than a single very powerful unit placed in a central area.
LogisVert financial assistance: verify the exact combination before promising an amount
An efficient heat pump may qualify for financial assistance through Hydro-Québec’s LogisVert program, but eligibility is not based solely on the SAMSUNG WindFree™ MaxHeat trade name. The exact combination of indoor and outdoor units must appear on the list applicable on the installation date.
Hydro-Québec specifies that the amount and the list of eligible models may change. The list in effect when the heat pump is installed must therefore be consulted before confirming a rebate.
For certain multi-unit buildings meeting specific conditions, the incentive may increase to $220 per 1,000 BTU/h of heating capacity at −8 °C, instead of $120, for a cold-climate ENERGY STAR®-certified wall-mounted heat pump. The announced criteria include having two or more units, being built in 1995 or earlier, and being located in a targeted area of energy insecurity.
We recommend keeping the following documents carefully:
- the detailed invoice;
- model numbers;
- serial numbers;
- the applicable AHRI or ENERGY STAR® reference;
- proof of payment;
- photographs of the nameplates;
- the official installation date.
Our post-installation advice
To get the best performance from heat pumps, we recommend using them as the primary heating source for most of the winter while keeping the existing electric heating as backup.
A simple strategy is to set the heat pump to a comfortable temperature and the baseboard heaters about two degrees lower. Hydro-Québec gives the example of setting a heat pump to 21 °C and baseboard heaters to 19 °C to prevent both systems from heating unnecessarily at the same time.
We also recommend:
- clean the indoor unit filters regularly;
- do not block the air intake or outlet;
- remove snow around the outdoor units without hitting the fins;
- avoid constantly turning the units off and back on;
- use a stable temperature;
- have the system inspected if unusual noise, a loss of capacity, or abnormal ice buildup appears.
An installation adapted to the property's architecture
This SAMSUNG wall-mounted heat pump project in Dollard-des-Ormeaux demonstrates that a successful installation depends as much on planning as on the equipment selected.
The two outdoor units were integrated into a limited space, above the basement openings and below the main windows. The wall brackets keep the passage clear, the height protects the units from winter snow accumulation, and the spacing facilitates their operation and maintenance.
Every property has its own constraints. A brick facade, a narrow side passage, a balcony, a condominium, a shared wall, or multiple units requires different solutions. Our role is to determine a location that respects the manufacturer's technical requirements, the building's structure, applicable regulations, and the occupants' actual needs.
At AirGreen, we install wall-mounted heat pumps, multi-zone systems, and central equipment throughout Greater Montreal. Our approach remains the same in Montreal, Laval, Longueuil, the North Shore, and the South Shore: careful sizing, a well-planned line-set route, suitable supports, rigorous commissioning, and a clean result.