Installation of a Fujitsu AIRSTAGE Altair 500 wall-mounted heat pump in Carignan on a wall bracket

A compact, structured installation in Carignan, designed for Quebec’s climate and service access

At Carignan, we completed this Fujitsu AIRSTAGE Altair 500 wall-mounted heat pump installation with particular attention paid to the location of the outdoor unit, the strength of the support, the protection of the connections, and future accessibility for maintenance.

The project photo shows an outdoor unit installed at a suitable height on a metal wall-mounted support, directly in front of a section of foundation beneath the brick cladding. This choice keeps the heat pump clear of the ground while maintaining clear access to the unit. To the right of the unit, the connections are protected by a vertical line-set cover, and the electrical supply is neatly connected in the immediate vicinity of the system.

This type of installation is well suited to the realities of properties in Carignan and the South Shore, where it is necessary to consider not only indoor comfort, but also snow, freeze-thaw cycles, the space available around the house, and the configuration of the façade.

Why we chose a wall-mounted support

The outdoor unit was not placed directly on a slab or on a ground-level support. It is secured to a metal structure made up of horizontal rails, vertical arms, and triangulated braces.

This configuration offers several advantages:

• it keeps the heat pump above the area where snow and water may accumulate;
• it avoids unnecessarily blocking ground-level passage;
• it leaves space beneath the unit for inspections;
• it facilitates access to the service panels;
• it allows for a cleaner integration on certain façades;
• it reduces risks related to debris, splashes, and seasonal accumulation near the base.

The photo also shows anti-vibration interfaces beneath the unit’s support points. This detail helps limit the direct transmission of vibrations to the supporting structure.

For us, the choice of support is never a secondary detail. It is an integral part of the quality of the HVAC installation.

A neat finish despite a technically busy façade

The wall where the unit is located features several elements: a painted foundation, brick siding, electrical conduits, structural elements, and relatively limited space between various exterior components.

Rather than leaving the connections exposed, we routed them through an exterior line-set cover positioned on the right side of the unit. This finish protects the lines and significantly improves the overall appearance.

The result is compact: the unit is installed close to the wall without being enclosed in a confined space, and the condenser's front remains clear to allow air to escape.

In a wall-mounted heat pump, this clearance in front of the fan is essential. Poor placement can disrupt the discharge of hot or cold air, depending on the operating mode, and reduce system efficiency.

The Fujitsu AIRSTAGE Altair 500: an R-32 series with Inverter technology

The Fujitsu Altair 500 belongs to the H AIRSTAGE series of single-zone wall-mounted systems. Fujitsu offers this family in several capacities, including the 09KPAS1, 12KPAS1, 18KPAS1, 24KPAS1, 30KPAS1, and 36KPAS1 versions.

The exact capacity of the unit installed in Carignan cannot be read accurately enough from the photo's nameplate. We therefore prefer not to arbitrarily assign a BTU rating. For this type of project, selection must be based on the building's heating requirements and the precise specifications of the chosen model.

R-32 refrigerant: clearly visible on the installed unit

The marking R32 is visible directly on the photographed outdoor unit. Fujitsu uses this refrigerant in the Altair 500 series.

According to the manufacturer's documentation, R-32 has a global warming potential of 675, compared with 2,088 for R-410A, representing a stated reduction of 68%. Fujitsu also notes that R-32 systems require less refrigerant while maintaining the desired heating performance.

For homeowners replacing an older R-410A system, it is important to understand that an R-32 unit is not simply a change of label. Service procedures, technical requirements, and component compatibility must be followed.

Inverter modulation that follows actual needs

The Altair 500 series uses an Inverter compressor. This technology allows the system to adjust its capacity rather than operating solely in on-off mode.

In practice, this provides:

• more stable temperature maintenance;
• consumption better matched to the actual load;
• longer and generally more consistent cycles;
• quieter operation when demand is low;
• better comfort during transitional periods.

This type of modulation is particularly useful in spring and fall, when requirements change quickly throughout the day.

A heat pump designed for heating and cooling

The Altair 500 series is designed to provide both heating and cooling.

The Fujitsu specifications indicate a heating operating range of -15 °C to 24 °C for the models in the range.

In cooling mode, the specified range starts at -10 °C for several models. For the 18,000 to 36,000 BTU versions, Fujitsu also mentions special operation that can extend the cooling range down to -20 °C under certain configuration conditions.

For a homeowner in Carignan, this means that the system can be used for much of the year, but sizing and the heating strategy remain essential during periods of extreme cold.

Different performance depending on the model

The Altair 500 technical documentation clearly shows that performance varies by capacity.

The listed HSPF2 is:

• 26.0 for the 9,000 BTU model;
• 24.0 for the 12,000 BTU model;
• 22.0 for the 18,000 BTU model;
• 21.5 for the 24,000 BTU model;
• 22.0 for the 30,000 BTU model;
• 21.0 for the 36,000 BTU model.

ENERGY STAR ratings also vary by version. That is why, at AirGreen, we avoid presenting an entire range as though all capacities offered exactly the same performance.

A heat pump should always be selected based on the precise combination of the indoor and outdoor models.

An indoor sound level as low as 19 dB(A)

The indoor wall-mounted unit in the Altair 500 series is designed to operate at a low sound level.

Fujitsu specifies a minimum of 19 dB(A) in quiet mode for the 9,000 and 12,000 BTU models. Larger models have different minimum ratings, including 26, 31, and 32 dB(A), depending on capacity.

This feature is particularly useful when the indoor unit is installed in a bedroom, office, living room, or open-plan living area.

The system also offers six fan speeds in addition to automatic mode, allowing the airflow to be adapted to actual needs.

An indoor construction focused on durability

Fujitsu states that the indoor unit uses highly corrosion-resistant copper ProCore coils. The manufacturer also mentions a Hydro Fin finned heat exchanger to improve corrosion resistance and durability.

These features are particularly relevant in a Quebec environment, where units experience significant temperature fluctuations throughout the seasons.

More advanced controls and accessories than those of a basic heat pump

The Altair 500 series can accommodate several optional accessories and controllers.

The documentation specifically mentions:

• wired controllers;
• a Wi-Fi adapter;
• compatibility with the AIRSTAGE app;
• certain third-party interfaces;
• integration options with BACnet and Modbus;
• 24 V thermostat interfaces;
• controllers and gateways for different management systems.

This creates more possibilities in advanced residential projects or in certain environments where the heat pump must interact with other control systems.

Piping dimensions vary by BTU rating

When replacing a heat pump, we always check the dimensions of the existing lines before deciding whether they can be reused.

For the Altair 500 series, Fujitsu specifies:

• 9,000 and 12,000 BTU: 1/4 in. liquid and 3/8 in. gas;
• 18,000 and 24,000 BTU: 1/4 in. liquid and 1/2 in. gas;
• 30,000 and 36,000 BTU: 3/8 in. liquid and 5/8 in. gas.

This point is fundamental.

Existing piping is not automatically compatible simply because it already reaches the desired location. Its diameter must meet the requirements of the new unit, and its condition must also be checked.

The pipe lengths allow for several installation scenarios

The maximum permitted lengths also vary.

Fujitsu specifies up to:

• 20 m for the 9,000 and 12,000 BTU models;
• 30 m for the 18,000 and 24,000 BTU models;
• 50 m for the 30,000 and 36,000 BTU models.

The maximum permitted vertical difference can reach 15, 25, or 30 m depending on the capacity.

These values provide greater flexibility when the indoor unit must be installed far from the outdoor unit, for example on another floor or on a different façade.

However, this does not mean that it is preferable to use the entire available length. In an installation like this one in Carignan, our goal remains to keep the route logical, tidy, and efficient.

The electrical supply depends directly on the selected capacity

All versions operate at 208-230 V, 60 Hz, single-phase, but the breaker requirements vary.

Fujitsu indicates:

• 15 A for 9,000 BTU;
• 15 A for 12,000 BTU;
• 15 A for 18,000 BTU;
• 20 A for 24,000 BTU;
• 30 A for 30,000 BTU;
• 30 A for 36,000 BTU.

Before an installation, we therefore check not only the required heating capacity, but also the available capacity in the electrical panel and the circuit configuration.

What the Carignan photo teaches us about a proper installation

This installation demonstrates several principles that we regularly apply on the South Shore.

Raised outdoor unit

The compressor is positioned high enough that it does not sit directly in the area most exposed to water and snow.

Fan completely unobstructed

The condenser’s front is unobstructed. No nearby wall or large obstacle is located directly in front of the fan.

Access to service panels

The sides and front remain accessible. This simplifies inspections and future service work.

Protected lines

The side pipe cover protects the connections and improves the installation’s visual finish.

Stable structure

The metal bracket has several anchor points and triangular reinforcements. The goal is not simply to support the appliance’s static weight, but to keep the installation stable over time.

Mistakes we aim to avoid when installing a wall-mounted heat pump

A significant part of our work involves preventing problems that might not become apparent until after several seasons.

Among the most common mistakes:

• install the unit too close to the ground;
• place the condenser in an area with poor airflow;
• reuse non-compliant piping;
• choose the capacity based solely on square footage;
• neglecting the drain routing;
• forgetting to allow access for maintenance;
• installing connections without protection;
• choosing an insufficient electrical supply;
• mounting a bracket on an unsuitable surface.

For this Carignan project, the outdoor unit was integrated compactly while maintaining a logical placement.

Why capacity should never be chosen solely based on floor area

Two homes with the same floor area can have completely different needs.

Sizing depends in particular on:

• insulation;
• fenestration;
• orientation;
• the number of floors;
• solar exposure;
• the layout of the rooms;
• heat loss;
• air circulation;
• the homeowner’s heating expectations.

An oversized unit is not automatically more comfortable. An oversized heat pump can reach the requested temperature quickly and reduce periods of continuous modulation.

Conversely, an undersized unit may operate constantly at high capacity.

At AirGreen, our approach is therefore to choose the system based on the actual building, not merely on a simplified BTU-per-square-foot rule.

An installation adapted to the realities of Carignan and Greater Montreal

We install Fujitsu wall-mounted heat pumps in Carignan, as well as in Montreal, Laval, Longueuil, the North Shore, and the South Shore.

Each area presents different configurations: brick homes, properties with exposed foundations, balconies, narrow yards, units installed between buildings, or façades with multiple obstacles.

The task is to find the right location without compromising:

• performance;
• clearance;
• aesthetics;
• safety;
• future service.

This Fujitsu AIRSTAGE Altair 500 installation in Carignan sums up this philosophy well. The unit is compact, elevated, unobstructed, and installed with organized connections.

For us, a successful HVAC installation is not judged only on the day it is commissioned. It must also remain logical when a technician returns several years later for maintenance or a repair.

The quality of the support, refrigerant line routing, protective measures, electrical supply, and unit placement directly affects the system’s lifespan and ease of service.

This is precisely what we seek on every AirGreen project.