On a flat roof in Saint-Blaise-sur-Richelieu, the outdoor installation is just as important as the choice of heat pump.
This installation of a FUJITSU ORION XLTH+ in Saint-Blaise-sur-Richelieu shows a side of HVAC work that is rarely seen in final photos taken inside a home: everything that must be planned on the roof so the system operates properly throughout all four seasons.
The photo taken during our work shows the FUJITSU AIRSTAGE outdoor unit installed on a flat roof covered with gravel. Around the unit, you can see skylights, the building’s parapets, various roof outlets, and, above all, the elements specific to our job site: the heat pump’s metal bracket, our level, and the lines and wiring being connected.
This is therefore not a staged photo taken after the technicians had left. It captures a real moment during the HVAC installation, when the positioning and levelling of the outdoor unit must be checked before final commissioning.
For this project in Saint-Blaise-sur-Richelieu, choosing a FUJITSU ORION XLTH+ was particularly appropriate because of its cold-climate design. Fujitsu indicates that this series has a heating operating range down to -30 °C (-22 °F). The manufacturer’s range includes the 09KTAP1, 12KTAP1, and 15KTAP1 configurations.
On a flat roof in Quebec, however, the machine’s capacity is only part of the equation. You also need to consider snow, defrosting, water produced in winter, wind, clearance around the heat exchanger, the stability of the bracket, and the route of the refrigerant lines.
Why did we raise the outdoor unit?
The most obvious detail in the photo is the metal bracket that keeps the heat pump above the roof surface.
This arrangement is particularly important on a flat roof.
During winter, snow can quickly accumulate around an outdoor unit installed too low. A heat pump must be able to freely draw in and discharge air through its heat exchanger. If snow or ice obstructs a significant portion of the unit, its operation may be compromised.
The elevation therefore helps maintain useful clearance beneath and around the machine.
It also facilitates the management of water from the defrost cycles.
A heat pump that provides heating also produces water outdoors
A homeowner using a heat pump for the first time may be surprised by the amount of water that appears around the outdoor unit during the winter.
This is not necessarily a leak.
When the heat pump operates in heating mode, its outdoor coil may accumulate frost. The system periodically initiates an automatic defrost cycle to remove this buildup. The ice then melts and produces water.
On the ORION XLTH+, Fujitsu specifically provides a base pan heater designed for extremely cold climates, a relevant feature for a Quebec installation such as the one in Saint-Blaise-sur-Richelieu.
Nevertheless, we must physically install the machine in a way that allows this water to drain away.
If the unit is placed directly very close to a roof or a surface where water cannot drain properly, ice buildup can gradually become problematic.
Leveling: a detail clearly visible on our worksite
The blue level placed in front of the installation in the photo shows a simple but essential step.
An outdoor unit must be positioned correctly on its support. On a flat roof, you should never assume that the existing surface is perfectly even.
Roofs often have intentionally very slight drainage slopes to direct water toward the drains. A surface that appears perfectly horizontal to the eye may therefore have enough of a difference to require adjustments.
During our installation, we specifically check:
- the stability of the support;
- leveling the equipment;
- the clearances around the heat pump;
- the space beneath the unit;
- the route of the lines;
- future access for HVAC maintenance;
- the proximity of parapets and other obstacles.
This step prevents an excellent piece of equipment from becoming a poorly installed system.
A flat roof creates different constraints from a conventional wall-mounted installation
In several projects in Montreal, Laval, Longueuil, on the North Shore and the South Shore, the outdoor unit of a wall-mounted heat pump is installed on a wall bracket or a ground-level base.
In Saint-Blaise-sur-Richelieu, the configuration shown here instead required a rooftop installation.
This change in location affects several aspects of the work.
The lines must be properly protected and planned
The photo shows the pipes and cables running from the heat pump to a mechanical component located on the roof.
The refrigerant piping route must be selected to limit unnecessary stress on the lines, maintain a clean installation, and allow for future servicing.
For the ORION XLTH+ series, the specifications indicate piping of:
- 1/4 in. for the liquid line;
- 3/8 in. for the gas line.
These dimensions are specified for all three configurations—09KTAP1, 12KTAP1, and 15KTAP1—presented in the Fujitsu documentation.
The specified minimum piping length is 10 ft, while the maximum length can reach 66 ft, with a maximum elevation difference of 49 ft.
This flexibility becomes particularly useful when the outdoor unit is on the roof while the indoor unit is one or more levels below.
We must also think about the technicians who will return several years from now
A quality installation must remain accessible after the work is complete.
In the photo, the unit is not wedged against a parapet or placed in an area where it would be impossible to remove a service panel. A technician must be able to reach the connections, inspect the heat exchanger, perform tests, and service the equipment without having to dismantle part of the building.
This is a criterion we consider very important at AirGreen.
The easiest location on the day of installation is not always the best location for the next ten years.
Why the FUJITSU ORION XLTH+ is an interesting heat pump for heating in Saint-Blaise-sur-Richelieu
Heating down to -30 °C: what this figure really means
Fujitsu documentation indicates that the three ORION XLTH+ configurations presented can operate in heating mode from -30 °C to 24 °C.
But a minimum operating temperature alone is not enough to evaluate a heat pump intended for Quebec's climate.
We also want to know what it can still produce when it is very cold outside.
This is where the data for this series becomes particularly interesting.
At -30 °C, Fujitsu indicates a maximum heating capacity equivalent to:
- 113% of the rated capacity for the 09KTAP1;
- 103 % for the 12KTAP1;
- 101 % for the 15KTAP1.
At -26 °C, these values are respectively 147%, 128%, and 116%.
This does not mean that every home can be heated solely by a wall-mounted heat pump, or that the required capacity will be identical from one building to another. Rather, it demonstrates why it is important to examine low-temperature performance data before choosing a unit.
Three capacities, but sizing must remain specific to each building
The range includes three rated cooling capacities:
- 09KTAP1 : 9,000 BTU/h;
- 12KTAP1 : 12,000 BTU/h;
- 15KTAP1 : 14,500 BTU/h.
At rated heating capacity, Fujitsu indicates 12,000, 15,300, and 17,400 BTU/h, respectively.
The exterior photo does not reliably confirm which of these three capacities was installed at this site. We therefore prefer not to arbitrarily assign a BTU rating to the unit based solely on its outdoor cabinet.
This caution also reflects how we size a wall-mounted heat pump.
We take the following factors into consideration, among others:
- the area to be conditioned;
- the interior volume;
- the level of insulation;
- the amount of glazing;
- the building’s exposure;
- heat losses;
- air circulation between rooms;
- the actual use of the spaces;
- the presence of other heating systems.
Installing the highest available capacity is not automatically the best solution.
Inverter modulation changes the system’s behavior
The FUJITSU ORION XLTH+ uses an Inverter compressor capable of modulating its output.
For example, the 12KTAP1 configuration has a cooling range from 3,100 to 17,300 BTU/h and a heating range from 4,500 to 27,300 BTU/h, depending on operating conditions.
This modulation capacity allows the heat pump to reduce its output when demand is low rather than operating continuously at full capacity according to an on-off cycle.
For occupants, this can contribute to a more stable temperature and quieter operation.
Very high energy efficiency depending on the selected capacity
The Fujitsu technical data sheet indicates TRÈS2 efficiencies of:
- 33,5 for the 09KTAP1 model;
- 31,5 for the 12KTAP1;
- 28,7 for the 15KTAP1.
The regional V CPSC2 values are respectively 11.5, 11.3, and 10.7.
These data are particularly useful when a homeowner compares several models of high-efficiency wall-mounted heat pumps.
However, they must always be interpreted alongside the system sizing, cold-weather performance, and the installation’s specific characteristics.
R-32: the refrigerant used by this generation of ORION XLTH+
In the photo of the worksite, the marking R32 is visible directly on the outdoor unit’s cabinet.
Fujitsu’s documentation confirms that all three configurations use R-32 refrigerant. The manufacturer assigns it a global warming potential of 675, compared with 2,088 for R-410A, representing a stated 68% reduction in GWP.
However, changing the refrigerant does not lessen the importance of rigorous commissioning.
A refrigeration installation requires, among other things, properly made connections, a leak test, evacuation, and compliance with the manufacturer’s requirements.
The roof may be more exposed to wind than a ground-level location
One factor we must consider on this type of project is the unit’s exposure.
The roof visible in the photo is largely unobstructed. An outdoor unit installed in this type of environment may be more exposed to wind than a heat pump located in a sheltered yard.
Air circulation around the unit must therefore be assessed without unnecessarily placing it in a confined space or too close to obstacles.
Fujitsu also indicates a low-noise outdoor operating mode and offers, for certain configurations, various accessories such as wind deflectors, snow guards, and hail guards. Their compatibility must be confirmed according to the exact model.
Outdoor noise must also be considered on a rooftop
Depending on the capacity, Fujitsu indicates outdoor sound levels ranging from 44 dB(A) for the 09KTAP1 configuration to 48 dB(A) for the 12KTAP1 and 51 dB(A) for the 15KTAP1 in cooling mode under the stated reference conditions.
The actual perceived noise level then depends largely on the surroundings.
On a roof, the unit’s position relative to windows, walls, nearby equipment, and adjacent properties can affect how sound propagates.
That is why we consider the heat pump’s position before beginning the connections.
ENERGY STAR and financial incentives: verify the exact combination
The configurations presented in Fujitsu’s documentation carry ENERGY STAR classifications, including designations associated with cold-climate systems.
However, when a homeowner wishes to take advantage of a grant or energy-efficiency program, we recommend verifying the exact combination of indoor and outdoor models and the applicable criteria at the time of the project.
Eligibility for financial assistance should never be inferred solely from the commercial name “ORION XLTH+”.
Programs, their equipment lists, and their amounts may change.
This project shows why the outdoor unit should never be considered a mere detail
When homeowners look at a ductless heat pump installation, their attention naturally focuses on the indoor unit: its appearance, size, noise level, and location in the home.
For us, the outdoor unit requires just as much consideration.
This installation in Saint-Blaise-sur-Richelieu provides a very concrete illustration.
The machine is located on a flat roof, elevated on a metal support, with the connections planned toward the building. The construction equipment visible in the photo, particularly the level placed in the foreground, reminds us that installation precision depends on steps that become invisible once the project is complete.
Before commissioning, we must ensure that:
- the unit is stable and correctly positioned;
- the clearances allow adequate airflow;
- the underside of the unit remains sufficiently clear for winter conditions;
- the refrigerant lines are routed correctly;
- the electrical connections are completed in accordance with the system requirements;
- the unit remains accessible for maintenance and service;
- the configuration promotes effective defrost and water management.
This is the work that transforms a good heat pump into a good installation.
An ORION XLTH+ well suited to a project where winter heating truly matters
The FUJITSU ORION XLTH+ combines several features sought for a Quebec installation: heating operation down to -30 °C, R-32 refrigerant, an Inverter compressor, a base pan heater, and high energy efficiency depending on the selected capacity.
But our Saint-Blaise-sur-Richelieu project above all highlights an essential reality: the manufacturer’s specifications must be supported by an installation adapted to the building.
On this flat roof, the positioning and elevation of the outdoor unit directly affected the system’s future performance.
At AirGreen, this is exactly what we strive to achieve on every ductless heat pump and HVAC installation project in Montreal, Laval, Longueuil, the North Shore, the South Shore, and surrounding municipalities: choose suitable equipment, then carry out an installation that takes the building’s actual conditions and Quebec’s climate into account.