Installation of a Fujitsu AIRSTAGE Orion XLTH wall-mounted heat pump in Côte-des-Neiges–Notre-Dame-de-Grâce, Montreal
AirGreen installs a Fujitsu Orion XLTH R-32 in Côte-des-Neiges–Notre-Dame-de-Grâce, on a raised metal support, in a rooftop area already occupied by several HVAC units.
In summer, the outdoor unit rejects the house's heat outside.
Generic illustration of this type of installation, not a survey of this job site. Tap a number.
Mounted level on a wall plate, high enough for the air to reach the whole room, with enough space around it to slide the filters out easily.
The refrigerant lines, the communication cable and the drain go through the wall in a single opening, sealed against water, cold air and insects.
Two insulated copper pipes connect the two units. Outside, a line cover can protect them from sun, knocks and weather.
A shut-off switch near the outdoor unit isolates it safely for service. It must stay accessible at all times.
The compressor and the fan. In heating mode it captures heat from the outdoor air, even in winter, and moves it inside.
On the ground or on the wall, it keeps the unit above accumulated snow. The unit stays clear and defrost water can drain away.
The fan needs to blow freely. Storage, a fence or a wall too close, and efficiency drops while noise goes up.
Replacing an old rooftop unit in Montreal without improvising the installation
In Côte-des-Neiges–Notre-Dame-de-Grâce, wall-mounted heat pump projects often take a very different form from those carried out in a detached home with a large yard. Buildings are denser, technical access may be through a roof, several outdoor units may share the same location, and each new piece of equipment must be positioned with the existing installations in mind.
That is exactly what this AirGreen project demonstrates.
In the photo taken during the work, we can see a new Fujitsu AIRSTAGE Orion XLTH R-32 wall-mounted heat pump in the foreground, installed on a raised metal base. A few feet behind it is another, older outdoor unit mounted on a wooden structure. The large windows and numerous units visible in the reflections also make it clear that we are in a multi-unit or high-density building environment, typical of certain areas of Côte-des-Neiges–Notre-Dame-de-Grâce in Montreal.
This project therefore did not simply involve placing a condenser on the roof. It was necessary to integrate a new machine into an already occupied technical space, maintain the required clearances, organize the connections, and above all create a suitable base for a heat pump intended to operate during Montreal winters.
The Fujitsu Orion XLTH series is designed for heating in cold climates down to -26 °C. Fujitsu documentation presents this range as a single-zone wall-mounted series using R-32, with Inverter technology, a base pan heater, and several capacities intended for residential applications.
What immediately distinguishes this rooftop installation
The most important detail in the photo is beneath the new heat pump.
We installed the outdoor unit on a raised metal support, positioned on a stable base. This configuration creates free space beneath the unit.
On a roof, this clearance is especially useful for several reasons:
- limit the machine’s contact with water present on the membrane;
- maintain clearance beneath the condenser during defrost cycles;
- reduce the risk of accumulated snow quickly reaching the bottom of the unit;
- facilitate certain HVAC maintenance tasks;
- allow for a cleaner, more structured installation;
- keep the heat pump level without relying directly on the roof surface.
This last point is important. A roof is not designed as a perfectly uniform mechanical slab. We must therefore adapt the installation method to its structure and finish rather than simply placing the unit wherever space remains.
A new heat pump among existing equipment
The photograph also reveals a very practical constraint: the new Fujitsu Orion XLTH is not alone.
An old outdoor unit is located behind it. Several other condensers are also visible in the reflection of the glass.
In this type of environment, we must avoid positioning the machines so that the hot or cold air discharged by one is immediately drawn in by another. Poor placement can promote air recirculation and reduce equipment performance.
We must also preserve:
- access to service panels;
- the circulation paths required by technicians;
- clearances around the heat exchangers;
- the possibility of replacing a unit in the future;
- access to electrical connections;
- enough space to carry out cleaning or repairs.
A heat pump installation in Montreal can therefore become a genuine technical planning exercise when a roof accommodates multiple systems.
Why the Fujitsu Orion XLTH is particularly relevant in Montreal
A heat pump installed on a roof in Côte-des-Neiges–Notre-Dame-de-Grâce is directly exposed to outdoor conditions.
Wind, snow, freeze-thaw cycles, and winter temperatures must all be taken into account.
According to the Fujitsu technical data sheet, the entire Orion XLTH range presented can operate in heating mode between -26 °C and 24 °C and in cooling mode between -10 °C and 50 °C.
The page dedicated to the system’s features also mentions:
- an Inverter compressor;
- a base pan heater designed for extremely cold regions;
- quiet outdoor operation;
- a compact outdoor unit;
- the use of R-32;
- a design that allows for different piping lengths depending on the model.
These features are particularly well suited to the realities of urban installations in Quebec, where winter performance, a compact footprint, and installation flexibility must be combined.
Five capabilities of the Orion XLTH family
The series documentation includes several model combinations:
- ASUH09KZAS / AOUH09KZAH1;
- ASUH12KZAS / AOUH12KZAH1;
- ASUH15KZAS / AOUH15KZAH1;
- ASUH18KZAS / AOUH18KZAH1;
- ASUH24KZAS / AOUH24KZAH1.
The advertised nominal cooling capacities are respectively 9,000, 12,000, 14,500, 18,000, and 22,000 BTU/h. For nominal heating, Fujitsu indicates 12,000, 16,000, 18,000, 21,600, and 25,200 BTU/h.
However, we never determine the exact capacity of an installation simply by looking at the machine’s exterior size in a photo.
For a property located in NDG or Côte-des-Neiges, sizing must take into account, among other factors:
- the area actually served;
- the layout of the rooms;
- the level of insulation;
- the amount and orientation of the windows;
- the floor where the dwelling is located;
- solar gains;
- winter heat loss.
In a building with large glazed areas like the one shown in the photo, these parameters can make a significant difference.
Very high seasonal efficiency depending on the selected capacity
The Orion XLTH series delivers high efficiency ratings.
Depending on capacity, Fujitsu indicates a SEER2 ranging from 24.0 to 33.1 and an HSPF2 region V ranging from 9.4 to 10.7.
For example:
12,000 BTU version
The 12K model lists:
- 12,000 BTU/h nominal cooling;
- 16,000 BTU/h nominal heating;
- 30.5 SEER2;
- 10.1 HSPF2 region V;
- 208 to 230 V power supply;
- specified 15 A circuit breaker.
15,000 BTU version of the lineup
The 15K version is listed at:
- 14,500 BTU/h nominal cooling;
- 18,000 BTU/h nominal heating;
- 27.5 SEER2;
- 10.1 HSPF2 region V;
- 208 to 230 V power supply;
- specified 20 A circuit breaker.
These data show why we compare the complete technical specifications rather than relying solely on the commercial label “12,000 BTU” or “15,000 BTU.”
What really matters at -21 °C and -26 °C
In the Montreal area, a figure such as SEER2 is useful, but it does not answer every question.
We also want to know what the unit can still produce when it is very cold.
Fujitsu specifically provides low-temperature heating data.
For the 12K model, the manufacturer indicates a maximum capacity equivalent to:
- 138 % of the reference rated capacity at -15 °C;
- 124 % at -21 °C;
- 102 % at -26 °C.
For the 15K version, the figures provided are:
- 140 % at -15 °C;
- 126 % at -21 °C;
- 109 % at -26 °C.
This information is particularly relevant for a Montreal homeowner looking for a heat pump that can make a meaningful contribution to heating rather than an appliance used primarily for summer cooling.
Compact outdoor unit: a real advantage on a crowded roof
All outdoor models shown in the data sheet are approximately 799 mm wide and approximately 290 mm deep.
The 09K, 12K, and 15K models weigh approximately 39 kg (86 lb) outdoors. The 18K and 24K models are listed at approximately 53 kg (117 lb).
On a roof where several units must coexist, every centimeter can count.
A relatively compact format makes it easier to find a location, but “compact” should never be confused with “being able to squeeze the unit against any obstacle.”
The fan, coil, and service panels must remain accessible.
Why we preferred a dedicated metal structure
The old unit visible behind the new one is installed on a wooden structure.
For the new Fujitsu unit, we used a dedicated metal base.
This approach provides more precise support for the condenser's support points and allows for a well-structured installation. The support is also much easier to adjust to the exact size of the unit.
In a replacement project, it is tempting to systematically reuse the existing support to save time.
That is not always the right decision.
Before keeping an old base, we must examine:
- its dimensions;
- its stability;
- its condition;
- its height;
- its compatibility with the new unit's feet;
- the clearance obtained beneath the unit;
- its relationship with the roof surface.
This project clearly shows that a new heat pump sometimes deserves a new support method rather than an improvised adaptation of the previous installation.
The technical details that make the difference in a Fujitsu installation in Côte-des-Neiges–Notre-Dame-de-Grâce
The piping must never be selected at random
The Fujitsu technical data sheet lists different refrigerant pipe sizes according to capacity:
- 09K : 1/4 in. liquid and 3/8 in. gas;
- 12K : 1/4 in. liquid and 3/8 in. gas;
- 15K : 1/4 in. liquid and 1/2 in. gas;
- 18K : 3/8 in. liquid and 5/8 in. gas;
- 24K : 3/8 in. liquid and 5/8 in. gas.
When an old heat pump is replaced, a common mistake is to assume that the existing piping is automatically compatible.
That is not the case.
The diameter, length, condition, and compatibility with the new unit must be checked before any decision is made.
Useful piping lengths for urban buildings
In buildings in Côte-des-Neiges–Notre-Dame-de-Grâce, the indoor unit may be several floors below or located some distance from the best outdoor location.
The Orion XLTH series offers interesting flexibility here.
The documentation indicates maximum lengths of up to:
- 25 m (82 ft) for the 09K and 12K;
- 30 m (98 ft) for the 15K;
- 50 m (164 ft) for the 18K and 24K.
The stated maximum vertical differences also range from 20 m (66 ft) to 30 m (98 ft), depending on capacity.
This can facilitate certain complex installations, but each route must always be planned properly. A manufacturer-approved maximum length is not a reason to add unnecessary detours.
R-32: clearly identified on the new unit
The logo R32 is visible on the new outdoor unit shown in the photograph.
The Fujitsu brochure lists R-32 with a stated global warming potential of 675, compared with 2,088 for R-410A, which the manufacturer says represents a 68% reduction in GWP.
This refrigerant is part of a new generation of systems and requires installation in accordance with the methods and specifications prescribed for the equipment.
Outdoor noise matters on a shared rooftop too
In a multi-unit building, outdoor sound levels can matter just as much as those of the indoor unit.
Fujitsu indicates the following approximate sound levels for the outdoor units in this range:
- 46/47 dB(A) for the 09K;
- 47/47 dB(A) for the 12K;
- 49/50 dB(A) for the 15K, 18K, and 24K, depending on cooling/heating mode.
Indoors, certain configurations can operate at levels as low as 23 dB(A) in quiet mode.
This is a particularly appealing feature in a condo, bedroom, or urban dwelling where acoustic comfort matters every day.
Built-in Wi-Fi for remote control
The series also includes built-in Wi-Fi connectivity for control and monitoring through the AIRSTAGE mobile app. Fujitsu documentation also mentions several options for wired controllers and interfaces compatible with various systems.
In an apartment, this feature can be used to adjust the setpoint remotely or prepare the temperature before returning home.
Rebate: verify the exact combination before promising an amount
The Fujitsu specifications indicate ENERGY STAR classifications, including cold-climate designations for models in this series.
However, this does not mean that a specific rebate amount can be determined solely from the name “Orion XLTH.”
For an actual installation, we must verify the exact indoor/outdoor unit combination, the capacity, and the applicable eligibility references for the program currently in effect.
This verification prevents basing a purchase decision on an inaccurate estimate.
The Mistakes We Avoid on a Montreal Roof
An installation like this requires avoiding several common mistakes:
- installing the heat pump directly on the membrane;
- automatically reusing an old base;
- placing two condensers too close together;
- blocking an access area for technicians;
- allowing defrost water to accumulate immediately beneath the unit;
- ignoring the height required when snow is present;
- using the wrong piping size;
- choosing the capacity based solely on floor area;
- forget that the unit will need to be serviced and eventually replaced.
It is precisely these details that turn a simple equipment installation into a professional HVAC installation.
A project representative of the HVAC challenges in Côte-des-Neiges and NDG
This AirGreen installation clearly illustrates the particular realities of the Côte-des-Neiges–Notre-Dame-de-Grâce area.
We regularly work in environments where the heat pump cannot simply be installed against a foundation at ground level. Condos, apartment buildings, buildings with accessible roofs, and densely developed properties require more planning.
Here, the presence of an older unit, nearby equipment, and the available roof surface led us to prioritize a compact, elevated installation.
The new Fujitsu AIRSTAGE Orion XLTH rests on its own metal support, maintains clearance beneath the unit, and integrates neatly with the existing mechanical environment.
We apply the same approach in our wall-mounted heat pump installations in Montreal, Laval, Longueuil, the North Shore, and the South Shore: analyze the building before deciding how to install the unit.
A cold-climate heat pump such as the Fujitsu Orion XLTH offers solid technical features — Inverter technology, R-32 refrigerant, operation down to -26 °C, high seasonal efficiency depending on capacity, built-in Wi-Fi, and a compact outdoor format — but its actual performance also depends directly on the quality of its installation.
In Côte-des-Neiges–Notre-Dame-de-Grâce, this project shows that a roof already occupied by several pieces of equipment can still accommodate a new heat pump in a clean, organized manner, provided the installation is designed around the unit, Montreal’s winter conditions, and future maintenance.
How it goes, from the first call to the end
The main steps of this kind of job at AirGreen. Every house has its quirks: the estimate brings them out.
We look at the room, the outside wall, the line route and where the outdoor unit will go. That is where the capacity gets chosen.
Model, capacity and price, in writing. We also check whether the model qualifies for assistance programs.
Floors and furniture protected, wall plate position marked level, wall opening located.
A single opening, with the slope the drain needs to flow outside.
Set on a stand raised above the snow, with the clearances the manufacturer requires.
Connected, insulated and protected. The opening is then sealed against water, cold air and insects.
A dedicated circuit and an accessible disconnect near the outdoor unit.
Leak test, vacuum, then start-up and a check of heating and cooling.
Remote, modes, filters: we show you the essentials before we leave.
- The on-site estimateWe look at the room, the outside wall, the line route and where the outdoor unit will go. That is where the capacity gets chosen.
- The quoteModel, capacity and price, in writing. We also check whether the model qualifies for assistance programs.
- Getting readyFloors and furniture protected, wall plate position marked level, wall opening located.
- The wall openingA single opening, with the slope the drain needs to flow outside.
- The outdoor unitSet on a stand raised above the snow, with the clearances the manufacturer requires.
- Lines, cable and drainConnected, insulated and protected. The opening is then sealed against water, cold air and insects.
- The electrical workA dedicated circuit and an accessible disconnect near the outdoor unit.
- Tests and start-upLeak test, vacuum, then start-up and a check of heating and cooling.
- The walkthroughRemote, modes, filters: we show you the essentials before we leave.
And at your place?
Two quick checks with real numbers: what heat costs, and what your current heaters add up to in BTU/h.
Conversion: 1 W = 3.412 BTU/h. An indication, not a load calculation: baseboards and furnaces are often stronger than the real need, and they can stay as backup. AirGreen confirms the capacity on site.
What to do, season by season
Three habits per season for this unit. They take a few minutes and prevent many calls.
- Clean the indoor unit's filters.
- Clear leaves and debris left on the outdoor unit by winter.
- Test cooling before the first hot days.
- Clean the filters more often when the unit runs a lot.
- Keep plants away from the outdoor unit.
- Check that no water drips from the indoor unit.
- Rake the leaves around the outdoor unit.
- Test heating before the first cold days.
- Book periodic maintenance before winter.
- Keep snow away from the stand and the front of the unit.
- Let the unit defrost: it is normal.
- Never hit the ice on the fins; call us if the unit stays iced up.
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What people ask us about this kind of work
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Text and photo: a real AirGreen Climatisation & Chauffage job. The diagrams are generic illustrations of the type of installation, not a survey of this job site. Sources of the added figures: airgreen.ca product pages (NEEP / AHRI performance), Hydro-Québec (Heat pumps page, LogisVert, read on 13 October 2026), Régie de l’énergie (rate D as of 1 April 2026).