Installation of a Samsung Premium FJM dual-zone heat pump in a residence with a cathedral ceiling in Longueuil

A multizone installation integrated into an open and demanding architectural design

This Samsung Premium FJM dual-zone heat pump installation in Longueuil had an immediately visible feature: one of the wall-mounted units had to be integrated into a space with a very high ceiling and an exposed structure composed of dark steel beams, a wood ceiling, and visible mechanical ducts.

In this type of residence, the success of an HVAC installation depends not only on the equipment’s capacity. The positioning of each indoor unit plays a decisive role in air distribution, comfort between levels, maintenance accessibility, and the room’s overall appearance.

At AirGreen, we therefore approached this project as an architectural and mechanical whole. The goal was not simply to mount a wall unit on the wall, but to create two consistent comfort zones from a single Samsung FJM outdoor unit, while respecting the property’s distinctive character.

The project photograph shows a white indoor unit installed high up, beneath the junction between the wood ceiling and the wall. Its location was chosen to allow effective distribution throughout the room’s large volume, without interfering with the beams, exposed pipes, decorative elements, and openings located lower down.

Why a dual-zone heat pump was particularly relevant

An open-concept home with a cathedral ceiling reacts differently from a traditional house with enclosed rooms and standard-height ceilings. Warm air naturally rises and can accumulate in the upper part of the building. In cooling mode, cool air can remain in the lower areas without necessarily reaching distant spaces or adjacent rooms.

A single wall-mounted unit, even when properly sized, cannot always treat the entire property evenly. A dual-zone heat pump instead makes it possible to assign an indoor unit to each priority area.

Depending on the layout of the home, this second zone can serve:

• a bedroom located away from the open living area;
• an upper floor or mezzanine;
• a closed office;
• a basement;
• a room with different sun exposure;
• a space used according to a separate schedule.

The Samsung Premium FJM range allows several compatible indoor units to be connected to a single outdoor unit. In this Longueuil project, the dual-zone configuration therefore reduced the number of visible outdoor units while providing better comfort control indoors.

A high-mounted location chosen to serve a large air volume

The wall-mounted unit visible in the photo is positioned above a large opening fitted with blinds, in an unobstructed area of the wall. This location offers several technical advantages.

First, the airflow can spread throughout the room without being immediately blocked by a cabinet, cross wall, or tall piece of furniture. Second, the unit is positioned at a height that promotes air distribution throughout a significant vertical space. Finally, its white finish remains discreet against the light-colored wall despite the visually striking environment defined by the black beams and wood ceiling.

However, the height had to be selected precisely. A unit installed too close to the ceiling may not have enough space to properly draw in air from above. Conversely, a unit installed too low could detract from the room’s aesthetics and reduce the air’s reach within the open space.

We must also preserve enough space to:

• remove and clean the filters;
• open the front panel;
• inspect the heat exchanger;
• perform a deep cleaning;
• access the connections if servicing becomes necessary.

In a high-ceilinged room, future accessibility must be planned from the outset. The fact that a location is technically feasible does not automatically mean it will be practical to service.

Integration with the beams, pipes, and exposed elements

The architecture of this property required special coordination. The steel beams, black pipes, and various visible mechanical elements created several constraints around the future location of the unit.

Before drilling, our technicians must check:

• the presence of metal structures;
• the position of the studs;
• the possible route for the refrigerant lines;
• the location of the wiring;
• the slope required for the condensate drain;
• the clearance in front of the louvers;
• vibration risks against an existing beam or pipe.

In this type of project, moving the unit a few centimeters can have significant consequences. A unit that is too close to a beam could draw in air unevenly. An existing pipe could prevent the panel from opening. Poor drain routing could require a condensate pump when natural drainage would have been possible with better planning.

The photograph shows that the unit was installed in a relatively open section of the wall, between the architectural constraints, while maintaining a balanced appearance.

An installation that respects the aesthetics of a contemporary interior

Homes with wood ceilings and exposed structures often have a strong visual identity. An HVAC installation carried out without aesthetic consideration can quickly become the most noticeable element in the room.

To avoid this effect, we look for a location where the unit can integrate with the building’s lines. Here, the white unit blends into the wall while remaining visually separate from the dark ceiling elements.

The pipe routing must also be handled carefully. Depending on the building’s configuration, the lines can be routed:

• directly through the wall behind the unit;
• inside interior trim;
• inside an accessible wall cavity;
• to a mechanical space;
• along a protected exterior route.

When direct routing behind the unit is possible, the result is generally more discreet. When it is not, we plan the trim to follow the building’s existing lines rather than creating an irregular path.

The role of the second zone in overall comfort

A dual-zone installation is not simply a matter of adding a second indoor unit. Both zones must be designed as parts of the same system.

The capacity of each indoor unit must match the actual load of its space. A large open area may require a different unit than a bedroom or office. The outdoor unit must then be compatible with the selected combination.

We specifically verify:

• the rated capacity of each indoor unit;
• the total connected capacity;
• the combinations approved by Samsung;
• the line-set lengths;
• the elevation difference between the units;
• the available capacity when both zones operate simultaneously;
• the system’s electrical requirements.

It would not be responsible to assign a precise BTU capacity to the installation based solely on the photograph. Exact sizing depends on several details that are not visible: floor area, insulation, fenestration, solar orientation, ceiling height, air infiltration, and room use.

At AirGreen, we therefore avoid approximations based solely on the building’s apparent size. A calculation tailored to the project remains the best way to prevent oversizing and undersizing.

Why oversizing could be problematic in this space

In a large room, it may seem logical to choose the largest possible unit. However, this approach can create several problems.

An oversized heat pump can quickly reach the requested temperature, then greatly reduce its output or shut down before properly homogenizing the air throughout the room. In cooling mode, it may also remove humidity less effectively if the cycles are too short.

Possible consequences include:

• temperature differences between the lower and upper parts of the room;
• higher indoor humidity;
• more frequent cycles;
• a draft-like sensation;
• less stable consumption;
• accelerated wear of certain components.

With a cathedral ceiling, height must be taken into account when calculating the load. The floor area represents only part of the volume of air to be treated.

Why undersizing must also be avoided

An undersized unit could run almost continuously during periods of intense heat or sustained cold without reaching the desired temperature.

In a room like this, heat accumulated near the ceiling, large glazed openings, and sun exposure can significantly increase the summer load. In winter, warm-air stratification can also create a sense of discomfort at occupant level, even if the temperature measured higher up is elevated.

Proper sizing therefore seeks a balance between:

• maximum capacity;
• low-load modulation;
• comfort between zones;
• dehumidification;
• noise level;
• electricity consumption.

The technical steps behind this Samsung installation in Longueuil

Planning the drilling and piping route

A wall-mounted unit installed high up requires careful preparation. The hole must be drilled in the right location, with sufficient slope when the drain operates by gravity.

Before opening the wall, we must identify potential obstacles. In a property with exposed beams and visible utility lines, there may also be hidden pipes, structural reinforcements, or electrical components nearby.

The route must accommodate:

• the liquid line;
• the steam line;
• the applicable communication and power cable;
• the drain pipe;
• the insulation around the lines;
• the connections required for the indoor unit.

Refrigerant lines must not be bent sharply. Bends must be made without crushing the copper or reducing its internal diameter. A deformed pipe can impair refrigerant circulation and system efficiency.

Managing condensation in a high-mounted unit

In air conditioning and dehumidification, the indoor unit removes moisture from the air. This water collects in a pan and then drains through a drain line.

In an installation like this, drain management is essential. A water leak several meters above the floor could damage the wall, blinds, furniture, or decorative objects.

We therefore check:

• the drain's continuous slope;
• the absence of a reverse slope;
• the strength of the connections;
• drainage before the work is completed;
• insulation of sections likely to condense;
• the drain's exterior outlet;
• protection against obstructions.

When gravity cannot reliably drain the water, a condensate pump may be considered. However, a pump adds a mechanical component, potential noise, and additional maintenance. We therefore prefer natural drainage when the architecture permits.

Mounting on a suitable wall

The indoor unit must be installed on a securely fastened mounting plate. The wall must support the unit without movement or vibration.

In a room where sounds can resonate because of the high ceiling and hard surfaces, vibration control takes on added importance. A small vibration transmitted to the wall could become more noticeable in the open space.

The plate must be:

1. perfectly level;
2. secured to a sufficiently solid structure;
3. positioned according to the manufacturer's clearances;
4. accessible for connection;
5. installed without deformation.

The unit is then hung and locked onto its mounting plate. We check that it rests properly against the wall and that the pipes do not push it forward.

Refrigerant circuit preparation

The two zones of a Samsung FJM system have their own connections to the outdoor unit. The quality of the refrigerant connections directly affects the reliability of the installation.

Our technicians pay particular attention to:

• clean cutting of the copper;
• deburring;
• flare execution;
• fitting alignment;
• controlled tightening;
• leak-tightness;
• insulation protection.

An improperly prepared connection can cause a slow leak. It may not be immediately visible, but it can lead to a gradual loss of performance, icing, or eventual system shutdown.

After the connections are made, the circuit must be tested and evacuated according to the appropriate procedures. The goal is to remove air and moisture before commissioning.

Testing Both Indoor Units

When starting the system, we do not test only the unit visible in the photograph. Both zones must be checked individually and together.

Commissioning includes, among other things:

• starting each unit;
• checking communication;
• checking the supply-air temperatures;
• testing the fan speeds;
• adjusting the louvers;
• inspecting the drains;
• checking for noise;
• validating simultaneous operation;
• explaining the remote controls to the customer.

We clearly identify which remote control corresponds to each zone. This simple step prevents a great deal of confusion, especially when the two indoor units are the same model.

Coordinated Operation of an FJM System

Each zone can generally have its own temperature setpoint. This allows one room to be set differently from the other depending on occupancy.

The two zones are nevertheless connected to the same outdoor unit. On a conventional residential multi-zone system, they must not simultaneously request opposite modes. One unit cannot normally heat while the other is cooling.

To avoid conflicts, we recommend:

• to use the same mode on both remote controls;
• to turn off a zone that does not need to operate;
• to avoid automatic mode when conditions could create conflicting demands;
• to choose reasonably similar setpoints;
• to check the setting of each unit when the seasons change.

This understanding of the system contributes to more stable operation.

How to Limit Air Stratification

In a high-ceilinged room, warm air tends to accumulate near the ceiling. Adjusting the louvers and ventilation therefore becomes particularly important.

In heating mode, the air should be directed downward to reach the occupied area. In cooling mode, the cool air can be directed more forward or slightly upward depending on the room’s geometry, as it will naturally descend.

It may also be useful to use a ceiling fan when the residence has one. In winter, a low speed can help bring the warm air accumulated near the ceiling back down without creating an uncomfortable draft.

The optimal setting depends on the arrangement of the furniture and how the space is used. We explain to the homeowner how to adjust the louvers rather than leaving them in the same position year-round.

Mistakes to avoid after installation

Setting an extreme temperature to speed up the system

Setting the air conditioning to 16 °C does not necessarily cool the room faster than using a reasonable setpoint. Instead, the system will run longer, with the risk of making certain areas too cold.

Blocking airflow

A tall piece of furniture, decorative object, or curtain placed in front of the unit can reduce its range. In this installation, the space in front of the unit must remain clear.

Neglecting the filters because of the unit’s height

Since the unit is installed at height, cleaning the filters requires safe access. Do not wait until airflow has decreased significantly before taking action.

Using unsuitable step ladders

Maintenance performed at height must always be carried out with stable, suitable equipment. A chair or piece of furniture is not a safe means of access.

Letting snow accumulate around the outdoor unit

In winter, the outdoor unit must be able to breathe. Snow must not block the heat exchanger or the air discharge area.

Maintaining a Samsung dual-zone heat pump

Each indoor unit has its own filters and heat-exchange surfaces. Both units must therefore be maintained, even when one zone is used less frequently.

Routine maintenance includes:

• inspecting the filters;
• washing the reusable filters;
• dusting the casing;
• visually checking the louvers;
• monitoring the drainage;
• clearing the area around the outdoor unit;
• observing unusual noises.

Over time, the blower, heat exchanger, and condensate pan can accumulate dust. Professional HVAC maintenance can then provide a more thorough cleaning than simply washing the filters.

For a unit installed at this height, professional service is especially useful, as it requires safe access equipment and appropriate protection for the room.

Potential eligibility for financial assistance

A heat pump’s eligibility for financial assistance cannot be confirmed based solely on the unit’s brand or appearance. It depends on the exact combination of indoor and outdoor models, the reference number recognized by the program, the capacity, and the criteria in effect at the time of installation.

For a multi-zone system, it is important to verify the entire combination, not just the Samsung Premium FJM trade name.

Before promising an amount, we verify in particular:

• the complete model numbers;
• the applicable performance reference;
• the equipment category;
• the purchase and installation date;
• the type of building;
• the required documents;
• the terms of the program in effect.

This verification prevents estimates based on incomplete information.

A representative project showcasing the complex installations carried out by AirGreen

This Longueuil installation clearly illustrates projects where the building’s environment influences the work as much as the equipment selected. The high ceiling, exposed wood, metal beams, and existing lines required careful planning.

At AirGreen, we install dual-zone heat pumps, multi-zone systems, and wall-mounted air conditioners in Longueuil, Montreal, Laval, on the North Shore, and on the South Shore.

Our work includes analyzing the building, selecting a compatible combination, positioning the units, planning the lines, completing the refrigerant connections and drainage, commissioning the system, and explaining its operation to the owner.

The desired result is not simply a cooler or warmer room. We want an installation that integrates properly with the building, remains accessible for maintenance, and distributes air logically throughout each zone.

What this installation provides for the occupants

The Samsung Premium FJM configuration allows occupants to better control two areas of the residence from a single outdoor unit. In the large room shown, the wall-mounted unit is positioned to serve a substantial volume while respecting the architectural constraints.

The second zone provides additional control in a space that would have been difficult to treat using only natural air circulation.

This installation therefore provides:

• more evenly distributed comfort;
• separate settings for the two zones;
• a single outdoor unit;
• discreet indoor integration;
• a solution suited to an open architectural layout;
• flexible use depending on room occupancy.

For owners of cathedral-ceiling homes, lofts, mezzanines, or open-plan spaces in Longueuil, this project shows why choosing the location and sizing is just as important as choosing the brand.