Installation of a Fujitsu AIRSTAGE Altair 700 wall-mounted heat pump in Saint-Michel, Montreal

A compact installation in Saint-Michel where the outdoor unit’s positioning mattered just as much as its performance

In the Saint-Michel area of Montreal, the space available around a building can quickly become one of the most important factors when carrying out a wall-mounted heat pump installation. For this project, we installed a Fujitsu AIRSTAGE Altair 700, an inverter heat pump using R-32 refrigerant, in a relatively narrow outdoor space between the property’s brick wall and a concrete structure.

The job-site photo clearly shows the result: the outdoor unit was not simply placed on the ground. We installed it on a raised, securely fastened metal bracket, with vibration-isolating support points. The lines were grouped and protected along the wall to achieve a clean, accessible installation suited to the immediate surroundings.

This type of detail is particularly important in Montreal, where an outdoor heat pump must contend with snow, meltwater, ice, temperature fluctuations, and spaces that are often more limited than in less densely populated residential areas.

Fujitsu AIRSTAGE Altair 700: a wall-mounted heat pump designed around efficiency

The Fujitsu Altair 700 belongs to the H series of AIRSTAGE single-zone wall-mounted systems. The technical documentation provided lists two capacities in this family:

• 09KMAS1: nominal cooling capacity of 9,000 BTU/h and nominal heating capacity of 12,000 BTU/h;
• 12KMAS1: nominal cooling capacity of 12,000 BTU/h and nominal heating capacity of 14,000 BTU/h.

The exact capacity must always be confirmed using the complete model number of the installed equipment and, above all, selected according to the building’s actual needs. A larger heat pump is not automatically a better heat pump. Sizing must take into account the floor area, insulation, sun exposure, room layout, and heat loss.

According to the Fujitsu data sheet, the 09KMAS1 version has a TRÈS2 of 30.0 BTU/hW, while the 12KMAS1 has 27.5 BTU/hW. Both models are also listed as ENERGY STAR and ENERGY STAR for cold climates in the manufacturer's documentation.

On the outdoor unit photographed in Saint-Michel, the EnergyGuide label is particularly visible and displays a cooling efficiency rating of 30.5 as well as a heating rating of 12.7. This is a good example of the importance of consulting not only the commercial name of a series, but also the energy label and the precise model number of the installed combination.

An R-32 heat pump rather than an older R-410A design

One of the immediately visible details on the outdoor unit is the identification R32.

Fujitsu states in its documentation that R-32 has a global warming potential of 675, compared with 2,088 for R-410A, representing an announced 68% reduction in GWP. The manufacturer also points out that systems using this refrigerant can operate with a reduced amount of refrigerant.

For a new HVAC installation in Montreal, this technology change is relevant. Choosing a heat pump is no longer based solely on the number of BTUs. The type of refrigerant, compressor modulation, seasonal efficiency, operating limits, and service availability must also be considered.

Why we raised the outdoor unit

One of the most interesting elements of this Saint-Michel installation is the metal support visible beneath the heat pump.

Placing an outdoor unit directly at ground level can cause several problems in our climate. Snow accumulation can interfere with air intake and discharge. During defrost cycles, water drained by the heat pump can also freeze beneath the unit and gradually form a mass of ice.

In this installation, the support keeps the heat pump at a safe distance from the ground while creating a stable mounting.

We can also see vibration isolators between the base of the Fujitsu and the metal structure. They are small components, but they play a tangible role:

• they limit the transmission of vibrations from the unit to its support;
• they help reduce certain structural noises;
• they prevent direct metal-to-metal contact between the unit and the structure;
• they provide a more professional-looking finish to the installation.

In an urban neighbourhood like Saint-Michel, where buildings and neighbours may be relatively close together, paying particular attention to noise and vibrations is especially useful.

A tight location that requires careful HVAC planning

The heat pump is installed against a brick wall, with a concrete structure to its right. This configuration requires us to consider several factors before even securing the bracket.

In particular, sufficient space must be preserved to:

1. allow the airflow required by the outdoor unit;
2. preserve access to the panels required for maintenance and diagnostics;
3. properly organize the refrigerant lines;
4. prevent an obstacle from interfering with the heat pump’s operation;
5. maintain a solid installation despite the available space.

The Fujitsu’s large front grille remains completely unobstructed in the photo. This is important because the outdoor fan must be able to move a significant amount of air without unnecessary obstructions.

A common mistake is to choose the location based solely on appearance or the required line length. At AirGreen, we also consider future access to the system. An installation may look perfect on the day it is completed, but if a technician cannot properly access the components a few years later, the initial location choice was incomplete.

Compact piping that provides plenty of design flexibility

The Altair 700 technical data sheet indicates the same piping dimensions for both capacities shown:

• liquid line: 1/4 in;
• gas line: 3/8 in;
• minimum length: 3 m (10 ft);
• maximum length: 20 m (66 ft);
• maximum vertical difference: 14.9 m (49 ft).

The documentation also specifies a precharge for a line length of up to 14.9 m (49 ft).

This ability to accommodate up to 66 feet of refrigerant line length provides flexibility in projects where the indoor unit cannot be placed directly on the other side of the exterior wall.

This frequently occurs in our installations of wall-mounted heat pumps in Montreal, Laval, Longueuil, the North Shore, and the South Shore. A kitchen, stairwell, window, terrace, balcony, or property boundary may prevent the shortest route.

Our goal, however, remains to choose a route that is logical, protected, and as clean as possible.

Protected and organized lines along the building

In the project photo, the mechanical passage rises behind the unit inside a vertical finishing chase placed against the brick wall.

This type of finish protects the installation components while avoiding leaving the lines exposed on the façade.

In a wall-mounted installation, we have to manage several elements in a relatively small area:

• the copper refrigerant lines;
• the pipe insulation;
• the communication and power wiring according to the configuration;
• the drainage of condensate from the indoor unit.

The quality of an installation is often evident in how these elements are arranged. Perfectly sized pipes are not enough if their route is poorly protected, drainage is problematic, or the exterior finish is neglected.

A relatively light electrical supply for this level of performance

The Altair 700 series presented in the documentation operates on:

208 to 230 V / 60 Hz / single-phase, with a 15 A circuit breaker indicated for the 09KMAS1 and 12KMAS1 models.

For the 09KMAS1 version, Fujitsu indicates a nominal/maximum cooling current of 2,9/6,4 A and in heating mode of 3,8/9,4 A.

For the 12KMAS1 version:

• cooling: 4,3/6,9 A;
• heating: 4,6/9,4 A.

These values illustrate one of the advantages of a modern inverter heat pump: the compressor does not operate solely according to an on-off logic. It modulates its operation according to demand to maintain a more consistent temperature.

This can improve comfort while limiting abrupt starts and significant temperature fluctuations in the room.

Heating and cooling with a single heat pump

The Fujitsu AIRSTAGE Altair 700 is a reversible heat pump, so it is used for both summer cooling and heating.

The operating range stated in the documentation is:

• -10°C to 50°C in cooling mode;
• -15°C to 24°C in heating mode.

It is important to interpret this information correctly. A minimum operating temperature is not the same as an identical guaranteed capacity at all temperatures.

When selecting a heat pump for Montreal, we always examine how the system performs in heating mode based on the building. Low-temperature performance, the actual available capacity, and the existing heating system may become more important than the maximum efficiency rating shown for milder conditions.

An indoor unit that can operate at just 19 dB

Acoustic comfort is another interesting feature of the series.

Fujitsu states that the indoor unit can reach a sound level as low as 19 dB(A) in quiet mode. The other stated levels are 30 dB(A) at low speed, 35 dB(A) at medium speed, and 40 dB(A) at high speed in cooling mode.

For homeowners who want to install a wall-mounted heat pump in a bedroom, living room, or office, this fan modulation may be more significant in everyday use than a simple difference of a few points in an efficiency rating.

The outdoor unit also offers relatively contained sound levels depending on the capacity selected. The documentation specifies, among other figures, 44 dB(A) in cooling mode for the 09KMAS1 model and 48 dB(A) for the 12KMAS1.

Integrated Wi-Fi and remote control

The Altair 700 series also includes integrated Wi-Fi connectivity, allowing remote monitoring and control through the AIRSTAGE mobile app.

For a homeowner, this notably makes it possible to adjust the temperature without being in front of the unit’s remote control.

The platform can also accommodate various optional interfaces and controls. Fujitsu documentation mentions, among other things, wired controllers, 24 V thermostat interfaces, and compatibility with BACnet and Modbus solutions through appropriate accessories.

This level of connectivity can become relevant when the heat pump needs to be integrated into a more sophisticated control strategy in a home or small building.

ProCore coil and a design built for durability

Altair 700 documentation also indicates the use of highly corrosion-resistant copper ProCore coils in the indoor unit.

In the HVAC field, we place great importance on these manufacturing details. A heat pump’s efficiency is important when purchasing it, but its ease of maintenance and the durability of its components matter just as much over many years.

A properly installed system must also remain serviceable. The filters in this Fujitsu unit are washable, which simplifies routine maintenance performed by the homeowner.

We recommend checking the condition of the filters regularly rather than waiting until they are completely clogged with dust. A blocked filter reduces airflow, which can affect the system’s comfort and performance.

ENERGY STAR and subsidies: verify the exact model number

The Altair 700 series documentation indicates ENERGY STAR ratings, including a cold-climate classification.

This type of certification may be relevant when a homeowner is reviewing the financial assistance programs applicable to a heat pump installation in Quebec. However, eligibility should never be assumed solely based on the logo shown on a brochure.

Before promising a subsidy, we check in particular:

• the exact indoor unit model;
• the exact outdoor unit model;
• certified combination;
• capacity;
• the program criteria applicable at the time of installation;
• the documents required for the application.

Programs and their criteria may change. Checking carefully before purchasing avoids choosing a unit on the assumption that financial assistance will automatically be granted.

What this Saint-Michel installation demonstrates

This project is a good example of the difference between selling a heat pump and completing a full HVAC installation.

The Fujitsu unit is obviously the main component, but the final quality also depends on everything else:

• location selection;
• clearance around the outdoor unit;
• support suited to winter conditions;
• vibration reduction;
• pipe protection;
• drainage;
• electrical power supply;
• accessibility for future maintenance;
• system commissioning.

On this Saint-Michel project in Montreal, the elevated positioning is particularly relevant. Despite limited side clearance due to the concrete structure, the unit’s front remains unobstructed and the system is installed on a stable structure rather than at ground level.

This is exactly the type of situation where a few decisions made before drilling and connecting can make a difference throughout the heat pump’s entire service life.

The mistakes we seek to avoid when installing a wall-mounted heat pump

Over the course of our installations in Montreal, Laval, Longueuil, the North Shore, and the South Shore, certain mistakes come up regularly when we inspect existing systems.

Installing the outdoor unit too close to the ground

This increases the risk of problems with snow, ice, and defrost water.

Neglecting the clearance around the unit

An outdoor unit needs to breathe. An aesthetically pleasing location that is too enclosed can become problematic.

Using the wrong piping size

For this Fujitsu Altair 700, the documentation specifies 1/4 in. for the liquid line and 3/8 in. for the gas line. The dimensions should not be chosen based on habit or the old unit being replaced.

Choosing the capacity based solely on floor area

Two homes of the same size can have completely different needs. Insulation, windows, ceiling height, orientation, and room layout affect the heating and cooling load.

Forgetting about future maintenance

A heat pump installed in an inaccessible location will complicate every service visit.

AirGreen and Fujitsu heat pump installation in Greater Montreal

At AirGreen, we install heating, ventilation, and air conditioning (HVAC) systems throughout Greater Montreal, including Montreal, Laval, Longueuil, the North Shore, and the South Shore.

An installation like the one carried out in Saint-Michel illustrates our approach to the work: we consider not only the machine, but the complete environment in which it must operate.

The Fujitsu AIRSTAGE Altair 700 offers an interesting combination here: inverter technology, R-32 refrigerant, a compact outdoor design, integrated Wi-Fi, reduced sound levels, and high energy efficiency. But to fully benefit from these features, the installation must comply with the piping requirements, clearances, electrical supply, water drainage, and the building’s specific constraints.

That is why, for us, a good wall-mounted heat pump installation in Saint-Michel begins well before the equipment is turned on. It begins with choosing the right location, the right capacity, and an installation method suited to the property.