A compact installation above a large windowed area: every centimetre had to be used intelligently
This wall-mounted heat pump installation in Montréal-Nord perfectly illustrates a scenario we regularly encounter in apartments and condominiums across Greater Montréal: a bright room, a large glazed area, very little exterior wall space available, and the need to integrate the HVAC system without interfering with the everyday use of the space.
For this project, we installed a Fujitsu AIRSTAGE ORION XLTH wall-mounted heat pump directly above the windows overlooking the balcony. The photo clearly shows the main constraint: almost the entire width of the wall is occupied by large windows and a glass door. We therefore had to use the strip of wall between the top of the windows and the ceiling while maintaining an accessible, stable, and visually orderly installation.
The result is particularly interesting from an HVAC installation perspective. The indoor unit is positioned very high, without interfering with the openings or blinds, and the line route has been carefully grouped inside a white horizontal line set cover, which then connects to a vertical drop on the right side of the windows.
This detail looks simple once the project is complete. In practice, it requires precise planning before the first hole is drilled.
A typical layout in Montréal-Nord condos and apartments
In a building where the exterior walls are largely glazed, the installation options for a ductless heat pump quickly become limited.
We must take into account simultaneously:
- of the indoor unit’s width;
- of the space between the window frame and the ceiling;
- of the available structure behind the wall;
- of the complete opening of doors and windows;
- of the movement of the blinds;
- of the refrigerant line route;
- of condensation drainage;
- of future access for heat pump maintenance;
- of air circulation in the room.
For this installation in Montréal-Nord, the space above the window represented the most logical solution. The unit thus benefits from a high, unobstructed position without using a wall that could serve for furniture, a television, or other interior design elements.
Precise work around windows and blinds
The photo shows a particularly important detail: the unit is located immediately above the blind systems.
A poorly planned installation could easily have created a conflict between the heat pump, the window, and the window treatments. It is therefore not enough to measure only the height of the unit’s casing.
We must also anticipate:
- the opening of the heat pump’s lower flap;
- the direction of the louvers;
- the necessary clearance around the unit;
- access to the filter;
- the possible removal of the front panel for maintenance;
- the position of the blinds when they are fully raised.
In this project, the integration maintains a clear separation between the heat pump and the window elements. The wall-mounted unit remains accessible, and the finish naturally follows the upper line of the windows.
A horizontal line-set cover that is part of the final result
A wall-mounted installation is never limited to the indoor unit visible in the room.
Behind this finish run the refrigerant copper pipes, communication wiring, and condensate drain, depending on the system configuration.
For this Fujitsu ORION XLTH in Montréal-Nord installation, we used a white line-set cover running horizontally along the top of the windows. It then connects to a rounded elbow and descends along the right-hand wall.
This approach serves two objectives.
The first is technical: protecting and organizing the installation components.
The second is aesthetic: avoiding several visible lines or creating an irregular path on a wall that is highly exposed to view.
With large windows like these, natural light highlights every finishing detail. A crooked line-set cover, poorly aligned joints, or an uneven vertical drop would be immediately noticeable.
Why a high position is advantageous for air distribution
A wall-mounted heat pump generally draws room air in through its upper section and redistributes the treated air forward and downward.
A high-mounted position like the one used here therefore allows the unit to operate from the upper part of the room and direct air toward the occupied zone.
In a room with extensive windows, this strategy is particularly relevant. Large glazed areas can be a significant source of solar heat gain in summer and heat loss during cold periods.
The Inverter technology in the AIRSTAGE range allows the system to adjust its capacity rather than operating solely according to an on-off logic. Fujitsu describes this technology as enabling rapid temperature adjustment and modulated operation based on actual demand.
Why the Fujitsu AIRSTAGE ORION XLTH is particularly well suited to residential installations in Greater Montreal
A heat pump designed for cold-climate heating
For an installation in Montréal-Nord, winter performance matters just as much as summer cooling.
According to the Fujitsu technical documentation for the ORION XLTH series, the systems concerned offer a heating operating range down to -26 °C (-15 °F). The range includes the 9K, 12K, 15K, 18K, and 24K classes, all rated for this temperature range.
It is important to distinguish between the minimum operating temperature and the capacity actually available when it is very cold.
The Fujitsu specifications provide specific data on capacity retention at low temperatures. Depending on the model, the maximum available capacity at -21 °C and even at -26 °C remains substantial. For example, the documentation indicates maximum capacity values at -26 °C corresponding to 127%, 102%, 109%, 106%, and 80% of nominal capacity, respectively, for the five models presented.
For us, this kind of information is much more useful than simply claiming that a unit “operates at -26 °C.”
Several capacities, one appearance: why we never guess the BTU rating
The photo shows a compact Fujitsu unit, but the exact capacity cannot be confirmed visually.
The ORION XLTH documentation notably provides:
- 09KZAH1 : 9,000 nominal BTU/h in cooling mode;
- 12KZAH1 : 12,000 BTU/h;
- 15KZAH1 : 14,500 BTU/h;
- 18KZAH1 : 18,000 BTU/h;
- 24KZAH1 : 22,000 BTU/h.
The three smallest capacities also use an indoor unit with identical dimensions on the data sheet: approximately 980 mm wide, 280 mm high, and 240 mm deep. The 18K and 24K models increase to approximately 1,150 mm in width.
That is precisely why we avoid estimating the number of BTUs solely from a photograph.
During an installation or replacement, we work with the exact model numbers and the actual needs of the dwelling.
Energy efficiency that changes according to the selected capacity
The ORION XLTH series offers high efficiency, but the ratings are not identical across all capacities.
According to the Fujitsu data sheet:
- 9K : VERY2 33.1;
- 12K : VERY2 30.5;
- 15K : VERY2 27.5;
- 18K : VERY2 25.5;
- 24K : VERY2 24.0.
The regional V CPSC2 values range from 10.7 to 9.4 depending on capacity. All models presented in the document also carry ENERGY STAR ratings associated with the product line.
These figures highlight an important reality for homeowners shopping for a heat pump in Montreal: choosing a capacity larger than necessary does not automatically improve performance or comfort.
Sizing must match the building.
R-32, another important change in this generation of Fujitsu systems
This series uses R-32 refrigerant.
In its documentation, Fujitsu compares a global warming potential of 2,088 for R-410A with 675 for R-32, representing a reported 68% reduction in GWP. The manufacturer also states that its R-32 models use less refrigerant while maintaining the heating performance sought.
For recent HVAC installations in Montreal, Laval, Longueuil, the North Shore and the South Shore, it has become particularly important to check the type of refrigerant and the requirements specific to each model rather than considering all heat pumps interchangeable.
A quiet indoor unit suited to a living space
When a heat pump is located near a living room or frequently occupied space, the noise level becomes particularly important.
The Fujitsu data sheet indicates up to six fan speeds plus automatic mode. The smallest models in the series can go as low as 23 dB(A) in quiet mode, while the larger units have different ratings depending on their capacity.
The visible positioning in our Montréal-Nord project also contributes to acoustic comfort: the unit is installed very high and does not directly occupy the occupants’ visual or physical space.
Integrated Wi-Fi and remote control
The series also includes integrated Wi-Fi connectivity with remote monitoring through the AIRSTAGE mobile app.
The documentation also mentions several control solutions and optional interfaces, including wired controllers, as well as compatibility with certain BACnet and Modbus interfaces.
For a residential homeowner, Wi-Fi is generally the most useful everyday feature: adjusting the temperature remotely, adapting the settings before returning home, and making operation easier to control.
The piping must absolutely match the capacity
A detail often overlooked when replacing a heat pump is the diameter of the existing copper lines.
In this Fujitsu series, the dimensions are not identical for every capacity:
- 9K : 1/4 in liquid + 3/8 in gas;
- 12K : 1/4 in + 3/8 in;
- 15K : 1/4 in + 1/2 in;
- 18K : 3/8 in + 5/8 in;
- 24K : 3/8 in + 5/8 in.
This means that an old wall-mounted system cannot necessarily be replaced simply by connecting a new unit to the existing lines.
At AirGreen, we always check the diameters, the condition of the lines, and the manufacturer’s requirements before determining whether any part of the existing installation can be reused.
Mistakes this installation helps avoid
This installation in Montréal-Nord highlights several common mistakes we aim to avoid when installing wall-mounted heat pumps.
Installing the head too low
Above a door or window, a few inches can determine whether the blinds can still be used normally.
We therefore check the entire available space before installation.
Forgetting access for cleaning
The filter and the upper part of the unit must remain accessible. Positioning a heat pump extremely close to the ceiling can unnecessarily complicate HVAC maintenance.
Improvising the line-set route after the unit has been installed
The route must be planned before drilling.
In this project, the line set follows a very clean horizontal line before turning to the right. This visual continuity is the result of a decision made before the unit was permanently secured.
Choosing BTUs based solely on floor area
The home’s floor area is important, but it is not enough.
Large windows like those visible here directly affect the heating and cooling load. Sun exposure, insulation, room layout, ceiling height, and several other factors must also be considered.
A concrete example of our AirGreen approach in Montréal-Nord
This project is a good summary of how we work.
We are not simply looking for a place to mount a heat pump. We are looking for the best available location within the home’s actual layout.
Here, we had:
- a large glazed surface;
- access to the balcony;
- blinds installed directly below the available location;
- little free exterior wall space;
- a clear need to preserve the interior space.
We therefore used the upper section of the wall, installed the Fujitsu AIRSTAGE ORION XLTH above the windows, and routed the lines through a discreet, continuous cover.
The result preserves the room’s natural light, blocks no openings, and allows the heat pump to distribute air from a high, central point.
This is exactly the type of detail we apply in our heat pump installations in Montréal-Nord, Montreal, Laval, Longueuil, on the North Shore and the South Shore: assess the building before choosing the location, inspect the equipment before determining the piping, and plan maintenance before finalizing the finish.
Grants and eligibility: verify the exact model number
Fujitsu documentation indicates ENERGY STAR classifications for the ORION XLTH models shown. This may be an important factor when a homeowner is looking for a heat pump eligible for financial assistance programs available in Quebec.
However, eligibility should never be assumed solely because the name ORION XLTH appears on a quote.
The exact combination of the indoor and outdoor units must be verified, along with the references required by the applicable program at the time of installation.
For us, this verification is part of a serious HVAC recommendation: the exact model matters just as much as the brand displayed on the front of the unit.