In Roxton, a Rooftop Installation Designed to Withstand Quebec’s Real-World Conditions
Some wall-mounted heat pump installations stand out less because of the complexity of the equipment than because of the environment in which it must operate. In Roxton, we installed a Fujitsu AIRSTAGE Orion XLTH, a heat pump designed for cold-climate heating, with the outdoor unit positioned directly on a roof.
The photo of this installation clearly illustrates a situation we regularly encounter in HVAC in Quebec: choosing a high-performance heat pump is not enough. It is also necessary to determine where to install the outdoor unit, how to protect it from snow and water buildup, how to limit vibration transmission to the building, and how to maintain convenient access for future servicing.
For this project, the Fujitsu outdoor unit is installed on a raised metal structure, which is itself supported to distribute the load across the roof. This configuration raises the base of the unit above the roofing material and is especially important when a heat pump must operate during the winter.
A Fujitsu Orion XLTH Designed for Cold-Weather Heating
The Fujitsu AIRSTAGE Orion XLTH lineup belongs to the H series of single-zone wall-mounted systems. According to the Fujitsu technical documentation provided for this installation, the lineup includes systems corresponding to nominal cooling capacities of 9,000, 12,000, 14,500, 18,000, and 22,000 BTU/h, with nominal heating capacities ranging from 12,000 to 25,200 BTU/h, depending on the model.
A particularly relevant point for an installation in Roxton is its heating operating range. Fujitsu states that it can operate down to -26 °C, clearly positioning the Orion XLTH as a solution designed for Quebec’s cold climate.
For a homeowner comparing a heat pump in Montreal, Laval, Longueuil, on the North Shore, the South Shore, or in a more remote municipality such as Roxton, this data deserves far more attention than the simple nominal capacity listed on the sales sheet. In Quebec, a heat pump does not operate only at +5 °C. It must remain useful when the outdoor temperature drops sharply for several hours.
Heating capacity that remains highly impressive below freezing
The technical specifications for the Orion XLTH range also provide detailed information on maintaining capacity at low temperatures.
Depending on the selected capacity, Fujitsu indicates maximum capacities at -15 °C, -21 °C, and -26 °C that vary from the unit's nominal capacity. For example, the 12K model in this range is rated at 124% of its nominal capacity at -21 °C and 102% at -26 °C, according to the manufacturer's reference conditions.
This is an important consideration when a customer is looking for a wall-mounted heat pump for winter heating rather than a unit used primarily for cooling.
At AirGreen, we attach great importance to this distinction. Two heat pumps with similar nominal capacities can perform very differently when the temperature drops below -15 °C.
R-32: a new generation of refrigerant from Fujitsu
The unit visible on the roof clearly bears the identification R32.
The Orion XLTH range does indeed use R-32 refrigerant. In its documentation, Fujitsu compares its global warming potential with that of R-410A and indicates an approximately 68% reduction, with a stated GWP of 675 for R-32 versus 2088 in the comparison presented.
For us, the arrival of R-32 also changes certain practices in the field. The installer must work according to the procedures applicable to this refrigerant, use the appropriate tools, and comply with the manufacturer's requirements regarding the piping, charge, and commissioning.
The choice of a heat pump should therefore never be separated from the quality of its HVAC installation. An excellent unit that is poorly installed can lose a significant part of the benefit promised by its technical specifications.
A rooftop installation: why raise the outdoor unit?
In the photo of this installation in Roxton, the outdoor unit is not placed directly on the membrane or roofing material. It rests on a raised structure.
This detail is important.
A heat pump used for heating periodically produces water during its defrost cycles. When temperatures are low, this water can refreeze around the unit. An installation that is too low can therefore quickly become problematic if ice or snow accumulates around the base.
Elevating the unit helps to:
- maintain more space beneath the heat pump;
- facilitate drainage associated with defrost cycles;
- keep the equipment away from accumulations directly on the roof;
- reduce the risk of obstruction in certain lower areas;
- make certain maintenance work easier;
- avoid placing the heat pump directly on the roof covering.
The required height must nevertheless be determined based on the building’s actual surroundings and the recommendations applicable to the equipment.
Stability matters as much as height
On a roof, simply adding a metal support is not enough.
It is also important to consider weight distribution, mounting rigidity, compressor and fan vibrations, as well as the forces exerted by the wind.
The photo shows a unit installed on a metal frame supported by elongated bases. This arrangement distributes the contact points over a larger surface instead of concentrating the entire weight of the equipment on a few small points.
During our heat pump work in Montreal, Laval, Longueuil, the North Shore, and the South Shore, we encounter very different structures: flat roofs, balconies, brick walls, concrete foundations, loose ground, or extremely narrow side spaces. A solution that is acceptable for a single-family home may be completely unsuitable for a multi-unit building or a commercial roof.
Pay attention to the clearances around the unit
One of the most important factors when installing an outdoor unit is air circulation.
The large propeller visible behind the grille must move a considerable volume of air through the heat exchanger. Installing a heat pump too close to a wall, guardrail, another unit, or an obstacle can interfere with this airflow.
On a roof, other elements also come into play: ventilation outlets, parapets, chimneys, ducts, mechanical equipment, and existing structures.
In this installation, the unit is located in a relatively open section of the roof. The space in front of the fan is unobstructed, which promotes adequate air circulation.
The location of a Fujitsu heat pump should always be determined with the manufacturer’s required clearances in mind rather than simply choosing the most discreet location.
A compact outdoor unit, useful for challenging installations
Fujitsu presents the Orion XLTH outdoor unit as a compact platform that allows some installation flexibility. The documentation also specifies varying piping lengths depending on capacity.
The 9,000 and 12,000 BTU models can accommodate up to 25 metres, or approximately 82 feet, of piping, while higher capacities may allow greater distances depending on the model.
This feature becomes particularly useful when an outdoor unit must be installed on a roof while the indoor unit is located in a room farther away.
The refrigerant circuit must nevertheless be calculated correctly. A long line affects the amount of refrigerant, installation methods, elevation limits, and sometimes the ideal location of the equipment.
Different piping dimensions depending on capacity
This is a technical detail that should be verified before any installation.
The Orion XLTH lineup does not use exactly the same piping dimensions for every capacity.
The Fujitsu specifications indicate, among other things:
- 9K and 12K models: 1/4 in. liquid and 3/8 in. gas;
- 15K model: 1/4 in. liquid and 1/2 in. gas;
- 18K and 24K models: 3/8 in. liquid and 5/8 in. gas.
This information becomes essential when replacing an old heat pump.
It is risky to assume that the existing piping can necessarily be reused simply because the new unit has a similar capacity. The diameters, condition of the copper, previous refrigerant, total length, and manufacturer requirements must be verified.
At AirGreen, this type of verification is one of the technical details that can help prevent much more costly problems after startup.
A particularly quiet unit
Noise is a significant concern, particularly when the outdoor unit is installed on a residential roof or near a bedroom.
Depending on capacity, Fujitsu specifies an outdoor sound level of approximately 46 to 50 dB(A) for this lineup. Indoors, some models can operate as quietly as 23 dB(A) in quiet mode.
The quality of the installation nevertheless affects the actual result.
A quiet outdoor unit can become unpleasant if its vibrations are transmitted to a metal structure or roof. That is why the choice of support, its rigidity, and the contact points with the building are important.
Inverter technology and more stable comfort
The Orion XLTH uses an Inverter compressor.
Unlike a system that operates only in on-off mode at full power, an Inverter heat pump can modulate its output according to demand.
In a properly sized home, this helps maintain a more consistent temperature and reduce abrupt cycling.
Fujitsu also indicates several operating ranges between the minimum and maximum capacity. For example, the 12K model can modulate in cooling between approximately 3,100 and 16,000 BTU/h, while its heating capacity can vary between approximately 3,500 and 23,600 BTU/h.
This modulation capability is particularly useful during the fall and spring, when the house requires much less heating than in January.
Built-in Wi-Fi and remote control
The Orion XLTH documentation also mentions built-in Wi-Fi connectivity for monitoring and control through the AIRSTAGE mobile app.
For some users, Wi-Fi is simply a convenience. For others, it becomes genuinely practical.
In a second home, rental property, or property occupied only a few days a week, remote control makes it possible to adjust the temperature without being physically present.
Fujitsu also offers different control interfaces and integration options, including certain options compatible with BACnet and Modbus systems.
Energy Star and efficiency: look at the exact model's data
All models in the series presented in the Fujitsu specifications sheet have Energy Star ratings indicated by the manufacturer, but performance varies according to capacity.
The TRÈS2 values indicated in the documentation range from 33.1 for the 9K model to 24.0 for the 24K model, with 30.5 for the 12K model.
This is a reminder of an essential rule: two heat pumps should not be compared solely based on their brand.
You must compare:
- the exact capacity;
- low-temperature performance;
- minimal and maximum modulation;
- noise level;
- electricity consumption;
- the permitted piping length;
- the diameter of the refrigerant lines;
- compatibility with the building;
- the subsidy programs applicable at the time of the project.
Because financial assistance programs may change, we verify eligibility based on the exact model and the criteria in effect at the time of installation rather than automatically promising an amount based solely on the name of the product line.
This Roxton project perfectly sums up our approach: choosing the unit, but above all, successfully installing it
A high-performance heat pump must be suited to the building
This Fujitsu Orion XLTH installation in Roxton illustrates a point we consider fundamental at AirGreen: an appliance’s specifications are only one part of the project.
Final performance also depends on the outdoor unit’s location, the quality of the refrigerant connections, the vacuum performed before commissioning, drainage, the electrical connection, airflow, and compliance with clearance requirements.
On a roof, this list must also include support stability, vibrations, defrost-water drainage, and future accessibility.
Mistakes to avoid with a heat pump installed on a roof
Some of the mistakes we try to avoid with this type of installation come up regularly:
Installing the unit too close to the roof. A cold-climate heat pump must be able to handle snow and defrost cycles without quickly becoming surrounded by ice.
Neglecting vibrations. A roof can amplify certain noises that would barely be noticeable on a concrete slab at ground level.
Blocking airflow. A unit placed too close to an obstruction may recirculate its own air and operate under unfavorable conditions.
Choosing capacity based solely on floor area. Square footage alone is not enough to properly size a system. Insulation, exposure, windows, interior layout, and heat loss must also be considered.
Automatically reusing old piping. The Orion XLTH’s line diameters vary by capacity and must meet the manufacturer’s requirements.
Forgetting about future maintenance. Equipment that is difficult to access can turn a normally simple service call into a complex job.
What we look at before recommending a Fujitsu Orion XLTH
Before recommending a Fujitsu wall-mounted heat pump, we seek to understand how the building is actually used.
Will the heat pump need to provide most of the heating? Is the space open or divided into separate rooms? Where can the indoor unit be positioned to promote good air distribution? What is a realistic route for the piping and drain? Where should the outdoor unit be placed without compromising airflow or access?
These questions are particularly important for an installation such as the one in Roxton, where the rooftop location directly influences part of the project’s design.
Why the Fujitsu Orion XLTH Is Interesting in Quebec
The product line’s technical specifications explain why it may be an interesting option for many Quebec homeowners:
- heating operation advertised down to -26 °C;
- Inverter technology;
- R-32 refrigerant;
- Energy Star certification indicated for the product line;
- low sound level;
- integrated Wi-Fi;
- multiple capacities available;
- ductless wall-mounted design;
- ProCore indoor copper coil with increased corrosion resistance;
- basic base-pan heater designed for extremely cold climates.
However, the right capacity and configuration must always be selected according to the building.
The AirGreen experience from Montreal to Roxton
Our teams work on a wide variety of heating, air conditioning, and heat pump configurations in the Greater Montreal area and beyond.
Whether the installation is carried out in Montreal, Laval, Longueuil, on the North Shore, the South Shore, or in an area such as Roxton, our objective remains the same: to ensure that the machine is installed under conditions that truly allow it to deliver the expected performance.
This Fujitsu rooftop installation is a good example. The unit is visible, but much of the work lies in the decisions made around it: positioning, clearances, support, connections, and preparing the system for Quebec’s seasons.
For a property owner considering a Fujitsu AIRSTAGE Orion XLTH, we therefore recommend not focusing solely on the number of BTUs listed on the quote. The true quality of an HVAC project is measured as a whole: sizing, equipment selection, installation, commissioning, and accessibility for maintenance.