In Sainte-Clotilde, a compact installation where the choice of outdoor support matters as much as the heat pump
A wall-mounted heat pump may seem simple when looking only at the two units after the work is completed. However, the true quality of an HVAC installation depends on a series of much less visible decisions: outdoor unit placement, height above the ground, snow and water management, support stability, vibration control, refrigerant line length, electrical supply, service clearances, and piping protection.
For this installation carried out by AirGreen in Sainte-Clotilde, we installed a Fujitsu AIRSTAGE Altair 700, a single-zone wall-mounted heat pump using R-32 refrigerant. The completion photo notably shows something we consider very important in Quebec: the outdoor unit was not simply placed beside the building. It rests on a raised metal bracket, with support points designed to stabilize the unit and limit vibration transmission.
This configuration is particularly relevant in a municipality like Sainte-Clotilde, where an outdoor installation must be designed to accommodate seasonal variations, snow accumulation, drainage around the building, and repeated freeze-thaw cycles.
A Fujitsu Altair 700 designed to heat and cool one zone
The Fujitsu AIRSTAGE Altair 700 belongs to Fujitsu’s single-zone H series. The technical documentation provided for this range covers two wall-mounted configurations:
- ASUH09KMAS + AOUH09KMAS1, with a nominal cooling capacity of 9,000 BTU/h;
- ASUH12KMAS + AOUH12KMAS1, with a nominal cooling capacity of 12,000 BTU/h.
The outdoor photograph clearly identifies the Fujitsu AIRSTAGE family and shows the R-32 marking, but it does not show the nameplate in sufficient detail to determine with certainty whether the Sainte-Clotilde installation is the 9,000 or 12,000 BTU/h version. We therefore prefer not to assign a specific capacity based solely on the appearance of the unit.
This is an important distinction. When a homeowner compares heat pumps, a few thousand BTUs can affect the unit’s behavior, modulation, dehumidification, and comfort. At AirGreen, sizing therefore does not mean automatically choosing the machine with the highest BTU rating.
Performance that differs significantly from that of a conventional fixed-speed heat pump
The Altair 700 series uses an Inverter compressor. Unlike a unit that operates primarily by cycling on and off, an Inverter allows the heat pump to adjust its output to the building’s actual needs.
For the 09KMAS1 model, Fujitsu indicates a cooling capacity that can modulate from approximately 3,100 to 12,100 BTU/h, while the heating capacity ranges from approximately 2,800 to 14,500 BTU/h. The 12KMAS1 version, meanwhile, modulates from 3,100 to 13,800 BTU/h in cooling and from 2,800 to 15,000 BTU/h in heating.
This modulation range is valuable in a home where the heating and cooling load is constantly changing. A slightly chilly fall day does not require the same output as a January morning, and a humid summer evening does not represent the same need as a very hot afternoon.
A properly sized unit can therefore run longer at a low output rather than unnecessarily cycling on and off.
Up to 30.0 SEER2, depending on the configuration
The Altair 700 series technical sheet lists particularly high efficiency ratings for this wall-mounted format.
For the 09KMAS1 combination, the data notably indicates:
- SEER2: 30.0;
- HSPF2, Region V: 9.9;
- EER2: 16.4;
- COP2: 4.64.
For the 12KMAS1 combination:
- SEER2: 27.5;
- HSPF2, Region V: 8.5;
- EER2: 13.5;
- COP2: 4.32.
Both configurations are also identified in Fujitsu documentation as meeting ENERGY STAR ratings, including the designation associated with cold climates.
For a Sainte-Clotilde homeowner who still mainly uses electric baseboards, a heat pump of this type can therefore become the primary heating system for the area it serves during a significant portion of the winter, while retaining the existing electric heating as backup when necessary.
Heating down to -15 °C: a figure that must be interpreted correctly
The official operating range in heating mode specified for both models is -15 °C to 24 °C, while the cooling operating range extends from -10 °C to 50 °C.
This information deserves to be explained clearly.
Cold-climate certification does not automatically mean that a heat pump must replace every other heating source during the lowest temperatures observed in the Montérégie region. In the specific case of the Altair 700 presented in the supplied documentation, Fujitsu announces a heating range down to -15 °C.
We must therefore consider the heat pump and auxiliary heating as two complementary components of the comfort system. Hydro-Québec also recommends keeping an appropriate backup heat source when a heat pump reaches the limits of its operating range.
This is exactly the kind of detail that should be checked before purchase rather than relying solely on the terms “cold climate.”
The elevated outdoor unit: a highly visible detail in our installation
The photo of the Sainte-Clotilde project shows the outdoor unit installed on an independent metal stand, well above the slab.
This method offers several practical advantages.
Keeping the heat pump away from ground accumulation
During winter, a heat pump must be able to draw in and discharge air without gradually becoming surrounded by snow. Elevating the unit also facilitates the drainage of water produced during defrost cycles.
Defrosting is normal for a heat pump in heating mode. When moisture freezes on the outdoor coil, the appliance periodically runs a cycle to melt this buildup. You therefore need to plan for what will happen to this water beneath the machine when the outdoor temperature remains near or below freezing.
Stabilizing a compact unit without overlooking vibrations
The supports placed between the heat pump and its stand are also visible in the photo. A properly stabilized installation helps limit vibrations transmitted to the structure.
This is particularly relevant when the unit is located near a window, patio door, or occupied space.
The equipment itself also operates quietly: Fujitsu indicates 44 dB(A) in cooling mode and 47 dB(A) in heating mode for the 9,000 BTU/h version, and 48/50 dB(A) for the 12,000 BTU/h version. Indoors, the quietest mode goes down to 19 dB(A) in cooling mode.
A relatively light electrical supply: 15 A circuit breaker
Another practical advantage of this series concerns its electrical requirements.
Both documented configurations operate on a 208 to 230 V, 60 Hz, single-phase power supply, with a 15 A circuit breaker specified by Fujitsu.
For the 09KMAS1 version, the indicated maximum current reaches 6.4 A in cooling mode and 9.4 A in heating mode. The 12KMAS1 version reaches 6.9 A and 9.4 A, respectively.
This obviously does not mean that an installer can simply use any available circuit. Before a wall-mounted heat pump installation, we must always check the electrical panel, required protection, wiring, existing conditions, and requirements applicable to the complete installation.
1/4-in. and 3/8-in. refrigerant lines
For technicians and owners who want to know the connection details, the Altair 700 documentation is very clear:
liquid line: 1/4 in.
gas line: 3/8 in.
These dimensions are identical for the 09KMAS1 and 12KMAS1 configurations.
The indicated minimum piping length is 3 m, or 10 ft, while the maximum length reaches 20 m, or 66 ft. Fujitsu also indicates a maximum vertical difference of 14.9 m, or 49 ft, with a factory charge provided for up to 14.9 m of piping.
These data offer some flexibility for installations where the outdoor unit cannot be placed directly behind the wall-mounted unit.
The flexibility allowed by the manufacturer never eliminates the need to carefully plan the route. The more complex the path, the more thought must be given to the bends, mechanical protection, future accessibility, and the appearance of the finished work.
R-32: the new generation of refrigerant used by the Altair 700
The logo R32 is clearly visible on the unit photographed in Sainte-Clotilde.
According to Fujitsu, R-32 has a global warming potential of approximately 675, compared with 2,088 for R-410A, representing an announced 68% reduction in GWP. The brand also specifies that its R-32 systems require less refrigerant while maintaining the desired performance.
The arrival of R-32 also changes certain work practices in the field. A recent heat pump must be handled, connected, evacuated, and commissioned according to the requirements specific to the refrigerant specified by the manufacturer. We therefore never treat the replacement of an older R-410A heat pump as a simple box swap.
This Sainte-Clotilde project illustrates what differentiates a durable installation from one that is merely functional
The outdoor placement must be decided before drilling begins
A common mistake is to choose the indoor unit location first and then improvise the position of the outdoor unit.
Instead, we consider the entire route:
- air circulation around the condenser;
- possible snow accumulation;
- defrost water drainage;
- proximity to openings;
- accessibility for HVAC maintenance;
- pipe length;
- electrical routing;
- vibrations;
- outdoor appearance;
- possibility of removing the service panels later.
At the Sainte-Clotilde site, the visible elevation of the unit specifically helps avoid installing the outdoor unit too close to ground level.
A compact outdoor unit that makes certain difficult locations easier
The outdoor unit is the same size for the documented models in this series: approximately 799 mm wide, 542 mm high, and 290 mm deep, with a weight of 32 kg.
The indoor unit measures approximately 834 mm wide, 270 mm high, and 222 mm deep, and weighs only 10 kg.
This format is appealing in homes where available space is limited, but we never confuse “the unit fits” with “the location is suitable.” The clearances required for operation and servicing must also be preserved.
Integrated Wi-Fi and remote control
The Altair 700 series includes integrated Wi-Fi connectivity for remote monitoring and control through the AIRSTAGE mobile app. Fujitsu also offers several wired controllers and optional interfaces, as well as integration options with BACnet and Modbus for certain applications.
In a residence, Wi-Fi is primarily useful for adjusting the temperature remotely, checking operation, or preparing the house before the occupants return.
Nevertheless, we recommend starting with simple programming. An inverter heat pump generally performs better when allowed to maintain a relatively stable temperature rather than being continually subjected to large setpoint changes.
LogisVert Grant: verify the exact model before promising an amount
The supplied Fujitsu brochure classifies both documented Altair 700 configurations as ENERGY STAR appliances, including cold-climate certification.
For financial assistance, however, we always distinguish between technical certification and administrative eligibility.
Hydro-Québec currently indicates that the residential LogisVert program may offer financial assistance of up to $6,700 for certain eligible heat pumps. Hydro-Québec also provides a tool for checking a heat pump using its model number or AHRI number.
The amount applicable to a Fujitsu Altair 700 must therefore be confirmed with the exact combination of units, the corresponding AHRI number, and the installation date. We avoid presenting a theoretical amount as a guaranteed rebate.
Three mistakes to avoid with a wall-mounted heat pump in Sainte-Clotilde
Installing the outdoor unit directly in an area where snow accumulates
A high-performance unit cannot operate properly if the coil or the clearance around the unit is constantly obstructed. The height and location of the support must be part of the project from the outset.
Choosing BTUs based solely on floor area
Floor area is an indicator, not a complete calculation. Insulation, windows, orientation, number of floors, room layout, heat loss, and the area actually served must also be considered.
An oversized heat pump is not automatically better.
Neglecting backup heating because the unit is labeled “cold climate”
In the case of the Altair 700 documented here, the official heating range extends down to -15 °C. A strategy suited to the lower temperatures that Montérégie can experience must therefore be maintained.
The same installation rigor in Sainte-Clotilde, Montreal, Laval, Longueuil, on the North Shore, and the South Shore
This project clearly demonstrates our approach at AirGreen: we do not consider a heat pump installation complete simply because the units produce heating and cooling.
We also consider what will happen over several winters.
Will the support remain stable? Can the defrost water drain away? Will the technician be able to access the service panel? Are the lines properly protected? Could vibrations become noticeable indoors? Is the selected unit truly suited to the zone it serves?
These are the same questions we apply in our installations of wall-mounted heat pumps in Montreal, Laval, Longueuil, on the North Shore, the South Shore, and in Montérégie municipalities such as Sainte-Clotilde.
On this project, the Fujitsu AIRSTAGE Altair 700 using R-32, its compact format, and its elevated outdoor installation form a coherent whole: an efficient unit, but above all one installed in a way that takes into account the real conditions a Quebec heat pump will face year after year.