A rooftop installation requiring precision, stability, and a long-term vision
In Saint-Léonard, in eastern Montreal, our AirGreen team installed a FUJITSU ORION XLTH KZAH R-32 18,000 BTU wall-mounted heat pump, a high-efficiency system designed to provide reliable comfort for both summer air conditioning and winter heating. The project presented a significant peculiarity: the outdoor unit had to be installed on a flat roof, with rigorous attention paid to mechanical stability, clearance around the unit, membrane protection, and future accessibility for HVAC maintenance.
The construction site photo perfectly illustrates the type of installation we often encounter in dense neighborhoods of Montreal, particularly in Saint-Léonard, Rosemont, Villeray, Ahuntsic, Mercier–Hochelaga-Maisonneuve, and around residential areas where backyards are limited. In this specific case, the roof offered the best location to preserve ground space, comply with building constraints, and maintain optimal airflow around the outdoor unit.
The choice of the FUJITSU ORION XLTH 18,000 BTU model was not random. This wall-mounted heat pump stands out for its ability to maintain high performance in cold climates, its quiet operation, its use of R-32 refrigerant, its eligibility for the provincial LogisVert subsidy, and its design adapted to Quebec winters. For a homeowner in Saint-Léonard seeking a sustainable solution for efficiently heating and cooling a significant living area, this type of system represents a serious investment in daily comfort and energy performance.
At AirGreen, a successful HVAC installation is never limited to merely placing an appliance. Every detail counts: the support structure, the distance between the unit and the roof surface, the passage of refrigerant lines, vibration protection, adherence to manufacturer's clearances, defrost water drainage, electrical safety, and ease of access during maintenance visits.
Why the FUJITSU ORION XLTH 18,000 BTU was perfect for this project
The building required a solution capable of meeting two very concrete needs: effectively air conditioning a living area during hot spells in Montreal, and reducing dependence on traditional electric heating during winter. The FUJITSU ORION XLTH KZAH R-32 18,000 BTU model precisely met these objectives.
Its main technical characteristics are particularly relevant for a property located in Saint-Léonard:
- Cooling capacity: 18,000 BTU
- Heating capacity down to -26 °C
- Refrigerant: R-32
- Indoor unit: ASUH18KZAS
- Outdoor unit: AOUH18KZAH1
- AHRI: 215647921
- ENERGY STAR®: Yes
- ENERGY STAR® Cold Climate: Yes
- SEER2: 25.5
- HSPF2: 12.5
- EER2: 14.0
- Indoor sound level: approx. 30 to 46 dB(A)
- Outdoor sound level: approx. 50 dB(A)
- Voltage: 220V
- MCA: 20A
- MOP: 20A
- Piping: 3/8 – 5/8 inch
- WiFi included
- Warranty: 12 years compressor, 12 years parts, labor according to applicable options
- Provincial LogisVert subsidy: $1,632, subject to eligibility
For a homeowner, these figures are not just technical data. They translate into real comfort: a more stable temperature, better humidity management, more controlled electricity consumption, and reliable heating capacity when temperatures drop in January or February.
An outdoor unit installed on a flat roof: the details that make the difference
Rooftop installation requires a different approach from ground-level or wall-mounted installation. In Saint-Léonard, flat roofs are common, and they can be an excellent location for a wall-mounted heat pump, provided the work is carried out meticulously.
On this project, our team paid particular attention to protecting the roof membrane. The outdoor unit was installed on a raised aluminum structure, itself positioned on supports designed to distribute the load and prevent any direct perforation or excessive pressure on the membrane. The presence of rigid roof insulation, visible under the structure, highlights the importance of never improvising this type of installation.
A common mistake is placing an outdoor unit directly on unsuitable blocks or supports. In the short term, this may seem stable. In the long term, the risks are real: sagging, vibration, water accumulation, displacement caused by freeze-thaw cycles, premature wear of the membrane, or difficulty accessing the system during a service call.
In this case, the structure was designed to:
- keep the outdoor unit well above the roof surface;
- reduce the risk of snow accumulation around the bottom of the unit;
- maintain good clearance for the air expelled by the fan;
- facilitate drainage during defrost cycles;
- limit the transmission of vibrations to the building structure;
- allow safe access to components during HVAC maintenance.
This approach is essential for rooftop installations in Montreal, Laval, Longueuil, on the North Shore, and on the South Shore, where climatic conditions require increased resistance for outdoor systems.
The challenge of snow, frost, and defrosting
A heat pump operating in heating mode naturally produces water during defrost cycles. In winter, this water can freeze if not managed correctly. On a flat roof, the issue becomes even more important, as water or ice accumulation around the unit can impair performance, create a vibration risk, or complicate access to the system.
The FUJITSU ORION XLTH is designed for cold climates and incorporates features adapted to our winters. Its heating capacity down to -26 °C makes it a relevant choice for homeowners who want to use their heat pump not only as an air conditioner but also as a primary or supplementary heating source.
During installation, our team took care to position the unit to maintain adequate clearance all around. The front fan must be able to expel air without obstruction. The sides and back must also breathe properly to maintain the efficiency of the compressor and outdoor coil. A poorly positioned unit can consume more energy, produce less heat, and experience faster wear.
A discreet solution despite Saint-Léonard's urban density
In a neighborhood like Saint-Léonard, buildings are often close together. Neighbors, alleys, balconies, and inner courtyards are all constraints to consider. The sound level of an outdoor unit therefore becomes an important criterion, especially when an installation is on a roof or near a party wall.
The FUJITSU ORION XLTH 18,000 BTU offers an outdoor sound level of approximately 50 dB(A), allowing for more discreet integration than many older units. The indoor unit, meanwhile, can operate from approximately 30 dB(A) at low speed, a notable advantage for living rooms, bedrooms, condos, and apartments where acoustic comfort is as important as thermal performance.
At AirGreen, we always evaluate the location based on perceived noise, not just measured noise. A machine may be compliant on paper but poorly placed in reality. A reflective surface, an enclosed courtyard, or an adjacent wall can amplify sound perception. This is why site analysis remains a key step before any HVAC installation.
R-32 refrigerant: a modern choice for new installations
This model uses R-32 refrigerant, a more current option than traditional R-410A. R-32 offers better energy performance and has a lower global warming potential than previous generation refrigerants.
For homeowners in Montreal, Laval, Longueuil, the North Shore, and the South Shore, this detail is becoming increasingly important. HVAC equipment is rapidly evolving towards more efficient solutions that are better aligned with environmental requirements. Installing an R-32 wall-mounted heat pump today means choosing a unit better suited to current industry standards.
This transition does not mean that installation becomes simpler. On the contrary, it requires a qualified team, accustomed to handling procedures, commissioning, leak testing, vacuuming, and performance validation. A high-efficiency heat pump can only reach its full potential if the installation is carried out according to best practices.
An AirGreen installation designed for real performance, not just the spec sheet
The performance of a wall-mounted heat pump depends on the chosen model, but also on the quality of its installation. Two identical units can yield very different results depending on the length of the ducts, the quality of the vacuum, adherence to clearances, the precision of electrical connections, the insulation of the refrigerant lines, and the indoor configuration.
In Saint-Léonard, our team worked with a comprehensive approach: understanding the building, choosing the right positioning, securing the structure, protecting the roof, cleanly installing the ducts, and validating the operation of the entire system.
The importance of proper sizing: why 18,000 BTU
The choice of an 18,000 BTU capacity was appropriate for the volume to be treated, the dwelling configuration, and the owner's expectations. A unit that is too small would run too long without achieving the desired comfort. A unit that is too large would risk short cycling, poor humidity management, and premature wear of certain components.
Sizing is a step we take very seriously. It is not enough to say that a given area automatically corresponds to a certain number of BTUs. We must also consider:
- building insulation;
- solar orientation;
- glazed area;
- ceiling height;
- airflow between rooms;
- age of construction;
- presence of other heating sources;
- actual occupant usage;
- thermal losses in winter;
- heat gains in summer.
In several Montreal neighborhoods, buildings have been renovated in stages. One part may be well insulated, while another retains older characteristics. A good HVAC contractor must be able to recognize these details before recommending a solution.
An indoor unit designed for daily comfort
The ASUH18KZAS indoor unit was selected for its ability to distribute air efficiently, while maintaining quiet operation. Its motorized louvers allow for better air flow orientation, both vertically and horizontally. This feature is particularly useful in open spaces, where air must travel a sufficient distance without creating an uncomfortable draft directly on occupants.
The included WiFi connectivity also adds tangible value. The owner can adjust the temperature remotely, program time slots, reduce the setpoint when away, and prepare the indoor comfort before returning. In a city like Montreal, where work schedules, commutes, and temperature variations can change rapidly, this flexibility is highly appreciated.
What we check during commissioning
Once the physical installation is complete, commissioning is a crucial step. At AirGreen, we do not consider the job finished simply because the unit turns on. We verify the system's behavior under real conditions.
During this type of commissioning, our team notably validates:
- the proper start-up of the indoor and outdoor unit;
- communication between the two units;
- the conformity of the electrical connection;
- the stability of the outdoor support;
- the absence of abnormal vibration;
- the behavior in air conditioning mode;
- the behavior in heating mode;
- the quality of the drainage;
- the tightness of the refrigerant connections;
- the insulation of the lines;
- the basic settings of the remote control and WiFi;
- the client's understanding of daily use.
This step helps avoid several common problems: wrong mode selected, inappropriate fan speed, incorrect setpoint, excessive use of automatic mode, forgotten filter maintenance, or misunderstanding of defrost cycles in winter.
Mistakes to avoid when installing on a roof
The installation visible in this project in Saint-Léonard highlights an essential point: the roof is not just an empty space where any appliance can be placed. It is an integral part of the building's envelope. A bad decision can lead to costly problems.
Here are the mistakes we systematically avoid:
Installing the unit too close to the membrane
A unit that is too low can be surrounded by snow, water, or ice. It also becomes more difficult to inspect and clean. An elevated structure improves durability and accessibility.
Neglecting weight distribution
The load must be distributed correctly to avoid excessive pressure on a specific area of the roof. This is particularly important on older flat roofs.
Blocking airflow
An outdoor unit needs sufficient clearance. An obstruction in front of the fan or behind the coil can impair performance and increase electricity consumption.
Forgetting future maintenance
A system must be accessible. Technicians must be able to safely intervene to clean, diagnose, repair, or replace a component.
Underestimating vibrations
Even a quiet unit can transmit vibrations if it is poorly supported. The supports, structure, and positioning must be designed to limit this transmission.
A project representative of HVAC needs in Montreal
This site in Saint-Léonard is similar to several projects we carry out in Greater Montreal. Homeowners want to improve their comfort without compromising the aesthetics of their building, without losing outdoor space, and without creating noise pollution. The FUJITSU ORION XLTH wall-mounted heat pump responds well to this type of need when properly selected and installed.
We have carried out similar installations in Laval, Longueuil, Boucherville, Terrebonne, Repentigny, Saint-Hubert, Pointe-aux-Trembles, Anjou, and on the South Shore. Each building has its constraints, but the objectives are often the same: stable comfort, energy efficiency, reliable equipment, access to subsidies, and serious after-sales service.
LogisVert Grant: a significant financial advantage
The FUJITSU ORION XLTH KZAH R-32 18,000 BTU is eligible for a LogisVert provincial grant of $1,632, subject to compliance with current criteria. For homeowners, this aid can significantly reduce the net cost of the project.
However, it is important to understand that eligibility depends on several factors: exact model, AHRI number, property type, documentation provided, installation compliance, and program requirements at the time of application. At AirGreen, we provide the necessary information so that the client can submit a clear application.
The AHRI 215647921, ENERGY STAR® certification, and Cold Climate classification reinforce the relevance of this model in a Quebec context. It is not just a machine designed for air conditioning; it is also designed to contribute to heating when the climate becomes demanding.
The importance of maintenance after installation
Even an excellent wall-mounted heat pump needs regular maintenance to maintain its performance. The indoor unit filters must be cleaned, the outdoor coil must remain clear, the drains must be checked, and the overall condition of the system must be inspected periodically.
For a roof-mounted unit, maintenance becomes even more important. Leaves, dust, debris, snow, ice, and temperature variations can affect operation if the unit is neglected. An HVAC maintenance visit helps maintain performance, prevent premature failures, and extend the system's lifespan.
We generally recommend an annual inspection, especially when the heat pump is used intensively for heating and cooling. This simple habit can make a significant difference in electricity consumption and indoor comfort.
Why choose AirGreen for an installation in Saint-Léonard
AirGreen regularly operates in Saint-Léonard and throughout Greater Montreal. Our local experience allows us to understand the specific realities of buildings in the region: narrow alleys, flat roofs, condominiums, multiplexes, semi-detached houses, space limitations, noise requirements, and access constraints.
Our approach is based on a combination of technical competence, transparency, and attention to detail. We do not only seek to sell a machine. We aim to install the right system, in the right place, with a sustainable and clear method for the client.
An AirGreen installation includes, notably:
- a thorough analysis of the building's configuration;
- a recommendation adapted to the area and actual use;
- installation by qualified refrigeration technicians;
- special attention to supports, clearances, and vibrations;
- a complete start-up;
- clear explanations to the client;
- support for information related to subsidies;
- available after-sales service for adjustments, maintenance, and diagnostics.
A clean, stable, and adapted result for Quebec winters
The final result in Saint-Léonard is a discreet, solid installation, well integrated into the roof. The outdoor unit FUJITSU AOUH18KZAH1 rests on a stable structure, with adequate clearance and a favorable orientation for air circulation. The ducts are neatly grouped, access to components remains possible, and the entire setup respects the best practices we apply to our HVAC projects.
For the owner, the advantage is immediate: a system capable of efficient air conditioning during Montreal's summer heat, significantly contributing to heating during winter, and operating at a reasonable noise level. In the longer term, the quality of the installation protects the investment and reduces the risk of problems related to the roof, vibrations, or poor drainage.
A high-performance wall-mounted heat pump for Saint-Léonard and Greater Montreal
This installation of a FUJITSU ORION XLTH KZAH R-32 18,000 BTU wall-mounted heat pump in Saint-Léonard perfectly illustrates the type of project where the installer's expertise is as important as the quality of the equipment. The chosen model offers remarkable performance in air conditioning and heating, but it is the custom installation that allows for reliable daily performance.
For homeowners in Montreal, Laval, Longueuil, the North Shore, and the South Shore, this project demonstrates that it is possible to integrate a high-performance HVAC solution even when outdoor space is limited. A flat roof can become a strategic location, provided every detail is mastered.
The FUJITSU ORION XLTH 18,000 BTU combines energy efficiency, quiet operation, eligibility for an attractive subsidy, R-32 refrigerant, WiFi connectivity, and heating capacity down to -26°C. Installed by AirGreen, it becomes a complete solution to enhance comfort, reduce consumption, and effectively modernize a residential building.