Installation of a FUJITSU AIRSTAGE ORION XLTH wall-mounted heat pump in Kahnawake, on Montreal’s South Shore

In Kahnawake, a FUJITSU ORION XLTH installation designed to heat efficiently even when the Quebec winter sets in

At Kahnawake, this installation carried out by our AirGreen team perfectly illustrates what we look for when a homeowner chooses a new wall-mounted heat pump: a clean, discreet installation suited to the interior architecture and, above all, capable of providing truly effective heating during the cold months.

In the photo of this installation, the FUJITSU AIRSTAGE ORION XLTH indoor unit is mounted high on a clear wall, near the ceiling. This location makes effective use of the room’s natural air circulation while preserving usable wall space. The white unit blends discreetly into the light-coloured décor, and the installation remains visually understated, with no mechanical elements dominating the room.

Behind this simple appearance, however, is a system specifically designed for cold climates. FUJITSU technical documentation indicates that the AIRSTAGE ORION XLTH / Orion CTEB series can operate in heating mode down to -26 °C, with an Inverter compressor, R-32 refrigerant, a base pan heater for the outdoor unit and integrated Wi-Fi connectivity. The series includes several capacities suited to different residential needs.

For us at AirGreen, an installation like this is therefore not simply a matter of mounting a unit on the wall. The final performance depends on selecting the right capacity, positioning the indoor unit, placing the outdoor unit, piping length, drainage, electrical supply and the quality of the commissioning.

A heat pump designed for the climate of Kahnawake and Greater Montreal

In Kahnawake, as in Montreal, Laval, Longueuil, the South Shore and the North Shore, a heat pump must handle two very different realities: hot, humid summers and winter temperatures that can drop well below freezing.

The FUJITSU ORION XLTH is specifically designed for this year-round use.

According to the FUJITSU technical data sheet provided for this series, the operating range is:

• -10 °C to 50 °C in cooling mode;
• -26 °C to 24 °C in heating mode.

This means that the unit is not intended only to cool a home for a few weeks in the summer. It becomes a true component of the residential heating system.

Inverter technology plays an essential role here. Rather than constantly operating according to a full-capacity on-off logic, the compressor adjusts its operation to the building’s needs. As the indoor temperature approaches the setpoint, the system can reduce its capacity instead of shutting down completely.

In a well-insulated home, this modulation contributes in particular to:

• maintain a more stable indoor temperature;
• reduce significant comfort fluctuations;
• limit frequent start-up cycles;
• reduce noise levels during periods of low demand;
• improve energy efficiency when conditions allow.

An ORION XLTH range that allows the capacity to be precisely matched to the building

FUJITSU documentation presents several configurations of the ORION XLTH series. At nominal cooling capacity, the range includes 9,000, 12,000, 14,500, 18,000, and 22,000 BTU/h, depending on the model selected.

The corresponding models include:

• ASUH09KZAS with AOUH09KZAH1;
• ASUH12KZAS with AOUH12KZAH1;
• ASUH15KZAS with AOUH15KZAH1;
• ASUH18KZAS with AOUH18KZAH1;
• ASUH24KZAS with AOUH24KZAH1.

The photo of this installation in Kahnawake does not allow the nameplate to be read and therefore does not reliably confirm the precise capacity installed. We always prefer to preserve this distinction rather than arbitrarily assigning a capacity to a project based solely on the unit’s apparent dimensions.

This is also an important rule when a homeowner is shopping for a wall-mounted heat pump. Two units that look similar externally may have different capacities and features.

The right BTU capacity must take into account, among other factors:

• the actual area served;
• number of floors;
• insulation level;
• the number and orientation of the windows;
• solar gains;
• room layout;
• ceiling height;
• the building’s heat loss;
• the possible contribution of another heating system.

A larger heat pump is not automatically a better heat pump. An oversized unit can quickly reach its setpoint without necessarily providing the desired dehumidification or modulation performance. Conversely, insufficient capacity will force the equipment to work harder during demanding periods.

An indoor unit positioned to promote good air distribution

The photograph of the Kahnawake project makes it possible to observe several interesting aspects of the completed work.

The FUJITSU wall-mounted unit is installed high on the wall, with clear space in front of the air outlet. The nearby visible doors do not immediately block the airflow. The unit also benefits from a large open area in front of it, which is important when aiming to promote effective air distribution throughout the main area.

The choice of location should never be based solely on where the unit appears most aesthetically pleasing.

During an HVAC installation, we must also consider the route of the refrigerant piping, condensate drainage, access for maintenance, and airflow.

For a wall-mounted heat pump, we generally try to avoid:

• air blowing directly toward a bed or an area occupied continuously;
• an installation too close to the ceiling;
• obstructions immediately in front of the louver;
• a location that unnecessarily complicates condensate drainage;
• an excessive piping route when a better solution is possible;
• a location that would make filter cleaning or maintenance difficult.

This consideration before drilling is particularly important. Once wall penetrations have been made and the piping installed, relocating the unit becomes a much more significant undertaking.

Quiet operation: a practical advantage in a living space

FUJITSU documentation indicates indoor operation as low as 23 dB(A) for certain models in the range, in quiet mode.

In a bedroom, office, living room, or open living area, this feature can become much more important than a theoretical difference of a few points on a technical data sheet.

However, acoustic comfort also depends on the quality of the installation.

A heat pump that is properly secured, connected, and configured limits the risk of vibrations or unwanted noise. Outdoors, the unit’s base, the support used, the proximity of bedrooms, and sound reflection off walls must also be considered.

For installations in Kahnawake and on the South Shore, we must also take winter into account: snow, ice, water from defrost cycles, and possible accumulation around the outdoor unit.

Why the base pan heater is important in winter

FUJITSU indicates that the ORION XLTH outdoor unit has a base pan heater designed for very cold regions.

This feature is particularly relevant in Quebec.

During heating operation, the outdoor unit extracts heat from the outdoor air. When conditions favor frost formation, the system periodically performs a defrost cycle.

The water produced must then be able to properly leave the unit.

Poor management of this water can cause ice to accumulate beneath the equipment. That is why the positioning and clearance of the outdoor unit are just as important as the heat pump’s electronic specifications.

At AirGreen, we pay particular attention to this reality during our heat pump installations in Montreal, Laval, Longueuil, the North Shore, and the South Shore.

R-32: the refrigerant used by this new FUJITSU generation

The series presented in the documentation uses R-32 refrigerant.

FUJITSU indicates a global warming potential of 675 for R-32, compared with 2,088 for R-410A, representing an announced 68% reduction in GWP.

However, the choice of refrigerant should not be considered in isolation. For the homeowner, the system’s actual performance always depends on the installation as a whole: equipment selection, sizing, the quality of the refrigerant connections, evacuation, configuration, and commissioning.

The best equipment, if installed incorrectly, will still be a poor installation.

Piping details that vary by capacity

Another important point emerges from the technical specifications for the FUJITSU ORION XLTH: not all capacities necessarily use the same piping dimensions.

According to the FUJITSU table:

• the 9,000 and 12,000 BTU models use a liquid line of 1/4 po and a gas line of 3/8 po;
• the 15,000 model uses 1/4 in – 1/2 in;
• the 18,000 and 24,000 models use 3/8 in – 5/8 in.

The specified maximum piping lengths may also vary by model, reaching 25, 30, or 50 metres depending on the capacity.

These technical details explain why we always verify the exact model before reusing existing piping.

A refrigerant line already present in a home is not automatically compatible with a new heat pump.

An electrical supply to verify before installation

The series operates at 208–230 V, single-phase, 60 Hz.

Depending on the capacity, FUJITSU specifies 15- or 20-amp circuit breakers.

This information must be verified before installation to avoid completing the mechanical work and then discovering that the available electrical supply does not meet the requirements of the new equipment.

A well-prepared installation therefore requires coordination between the heat pump’s requirements and the characteristics of the building’s electrical panel.

Integrated Wi-Fi and remote control

The ORION XLTH range described by FUJITSU includes integrated Wi-Fi connectivity with remote monitoring through the AIRSTAGE mobile app.

For a homeowner, this feature can be useful for adjusting a setpoint remotely, checking the system's operation, or preparing the home's temperature before returning.

FUJITSU also offers several additional control options, including wired controllers and various interfaces for certain projects requiring more sophisticated integration.

This level of flexibility becomes particularly interesting when moving from a simple residential installation to a light commercial application or a building with additional control systems.

This Kahnawake project shows why installation quality matters as much as the choice of heat pump

An understated finish in a very bright interior space

The visible result in the photo is intentionally understated.

The FUJITSU AIRSTAGE indoor unit blends into the white wall and maintains a minimal visual presence. The lower flap remains unobstructed to allow air distribution, while the front panel remains easily accessible for filter cleaning.

This type of result is important to us: an HVAC installation must function properly, but it must also respect the space in which it is integrated.

A wall-mounted unit remains visible for many years. A few centimetres in its placement can therefore have a considerable impact on the final appearance.

Our approach at AirGreen for a wall-mounted heat pump installation

When we carry out a FUJITSU wall-mounted heat pump installation, our work involves much more than installing the two units.

Our attention focuses in particular on:

1. the capacity suited to the building's needs;
2. the placement of the indoor unit;
3. air circulation;
4. the safe and practical placement of the outdoor unit;
5. the routing of the refrigerant lines;
6. condensate drainage;
7. the electrical supply;
8. the quality of the refrigerant connections;
9. vacuuming the system;
10. commissioning and operational testing.

Each step can directly influence the system's long-term reliability and performance.

A common mistake: choosing solely based on the number of BTUs

In our projects in Montreal, Laval, Longueuil, Kahnawake, the South Shore, and the North Shore, we regularly meet homeowners who have already determined for themselves that they need 12,000, 18,000, or 24,000 BTUs based solely on floor area.

Floor area is useful, but it tells only part of the story.

Two 1,500 sq. ft. houses can have very different needs if one has several large south-facing windows, an open basement, and recent insulation, while the other has several enclosed rooms and a less efficient building envelope.

We therefore prefer to analyze the property's actual configuration before confirming a capacity choice.

A heat pump designed for heating, not just air conditioning

One of the most interesting aspects of this FUJITSU range is its low-temperature performance.

Depending on the model, the technical specifications even provide percentages of maximum heating capacity at -15 °C, -21 °C and -26 °C.

This way of presenting the data is much more useful for a Quebec homeowner than looking only at the rated capacity under moderate conditions.

When comparing two heat pumps for a home in Kahnawake, it is therefore useful to examine:

• seasonal efficiency;
• the available capacity when temperatures drop;
• the actual operating range;
• the sound level;
• the modulation;
• the type of refrigerant;
• the piping dimensions;
• the quality of the service and parts network;
• the quality of the proposed installation.

Maintenance: preserving airflow and efficiency

Even a properly installed FUJITSU heat pump requires maintenance.

The homeowner can help ensure the system operates properly by regularly cleaning the washable filters, keeping the air inlets and outlets clear, and monitoring the general condition of the outdoor unit.

It is particularly important to prevent snow, leaves or other debris from blocking airflow around the condenser.

Periodic HVAC maintenance also makes it possible to check the components, the cleanliness of the heat exchanger, condensate drainage and the system’s overall operation.

An installation representative of the results AirGreen strives to achieve

This project in Kahnawake clearly reflects our approach: selecting technology suited to the local climate and integrating it properly into the home.

The FUJITSU AIRSTAGE ORION XLTH offers several features that are particularly relevant for Quebec: heating down to -26 °C, Inverter technology, quiet operation, R-32 refrigerant, base pan heater, washable filtration, advanced controls and Wi-Fi connectivity.

But our work never stops at the technical specifications.

The difference between simply purchasing a heat pump and achieving a successful installation lies in all the details that are not always visible after the technicians leave: capacity selection, proper piping, connections, drainage, electrical supply, clearances, leveling, vacuuming and start-up.

This is the approach we apply at AirGreen for our wall-mounted heat pump installations in Kahnawake, Montreal, Laval, Longueuil, on the South Shore and the North Shore, with the goal of achieving a clean, durable system that is truly suited to the building’s needs.