A DoubleZone installation on an urban rooftop: precision, stability, and adaptation to the building
In the borough of Villeray–Saint-Michel–Parc-Extension, heat pump installations often require a very different approach than for a single-family home with an open backyard. Buildings are closer together, access can be complex, flat roofs are common, and ground space may be limited or completely unavailable. For this project, our AirGreen team installed a GREE FREE MATCH R32 DoubleZone heat pump, a 2-zone, 2-head wall-mounted configuration, with the outdoor unit positioned on a Montreal flat roof.
The photo of this installation shows a particularly representative example of HVAC work in an urban environment: an outdoor unit installed on an elevated structure, placed on adapted bases, with refrigerant lines neatly routed across the rooftop. Around the unit, you can see typical elements of a Montreal flat roof: gravel, membrane, vents, ventilation ducts, parapets, protective blocks, and restricted technical access. Every detail counts, as a rooftop installation must never compromise the membrane's waterproofing, the safety of workers, or the system's durability.
The client wanted a permanent solution to improve comfort in two distinct areas of the dwelling, while avoiding occupying outdoor ground space. In a dense area like Villeray–Saint-Michel–Parc-Extension, this constraint is common. Installing the outdoor unit on the roof then becomes a very relevant option, provided that the mounting is done methodically, clearances are respected, and future HVAC maintenance access is planned from the outset.
This achievement clearly illustrates AirGreen's expertise in multi-zone heat pump installations in Montreal, but also in comparable environments in Laval, Longueuil, on the North Shore, and the South Shore, where residential buildings and plexes may present similar technical constraints.
Why the GREE FREE MATCH R32 DoubleZone was suitable for this project in Montreal
The GREE FREE MATCH R32 system was chosen for its ability to power two indoor units from a single outdoor unit. In a Montreal dwelling, this configuration improves comfort without multiplying visible outdoor appliances. The result is cleaner, more efficient, and better suited to spaces where every square foot counts.
Two independent zones for better distributed comfort
A DoubleZone heat pump allows two living areas to be treated separately. In a plex, apartment, or townhouse, needs can vary greatly from one room to another. An open area exposed to the sun can quickly become hot, while a bedroom at the back remains cooler. An office may require a stable temperature during the day, while a living room is primarily used in the evening.
With a 2-head system, the client can adjust the temperature according to the actual use of each zone. This flexibility is one of the great advantages of multi-zone systems. It reduces the discomfort caused by a single heating or cooling source and allows for finer energy consumption management.
In this project, the 2-zone, 2-head configuration met a concrete need: to achieve balanced comfort in two distinct spaces, without installing two separate outdoor units. For a building in Villeray–Saint-Michel–Parc-Extension, this approach is particularly attractive because it limits outdoor clutter while significantly improving indoor comfort.
An elevated outdoor unit to protect the roof
One of the most important aspects visible in the photo is the support for the outdoor unit. The unit is not placed directly on the roof membrane. It is installed on an elevated structure resting on stable bases, with wooden supports and distribution slabs. This method helps distribute weight better, preserve the membrane, and reduce risks related to water, snow, or debris accumulation.
On a flat roof, a poorly designed installation can create significant problems:
- excessive pressure on the membrane;
- vibration transmitted to the structure;
- difficulty of access for service;
- snow accumulation around the unit;
- poor roof drainage;
- premature wear of roofing materials;
- risk of displacement if supports are not stable.
Our team therefore installed the unit with particular attention to stability, clearances, and roof protection. This type of mounting requires rigorous planning, as the roof is not just a practical location: it is a critical part of the building.
Well-routed refrigerant lines on a flat roof
In the image, the refrigerant lines and communication cables are visible near the unit. In a DoubleZone installation, these connections are more numerous than for a single-zone installation. Each indoor head must be connected to the outdoor unit with an appropriate circuit, adequate insulation, and sufficient protection.
On a roof, the routing of lines must be designed to avoid areas where water stagnates, places likely to be walked on, and prolonged direct contact with abrasive surfaces. The lines must also allow for some flexibility in the face of temperature variations, as materials expand and contract with the seasons.
At AirGreen, we pay particular attention to these details. A clean installation is not limited to an orderly appearance: it protects the system's performance, facilitates maintenance, and reduces the risk of long-term damage.
R32 refrigerant: current technology for multi-zone systems
The installed model uses R32 refrigerant, which is increasingly present in new generations of residential heat pumps. This refrigerant is appreciated for its thermal efficiency and improved environmental profile compared to several older refrigerants. For customers investing in a modern system, R32 represents a choice consistent with current market standards.
In the case of a GREE FREE MATCH R32, the interest is also linked to the system's versatility. The FREE MATCH range is designed to meet multi-zone needs, which allows for the design of a solution adapted to the building's reality instead of imposing a standard configuration.
An installation designed for the realities of Villeray–Saint-Michel–Parc-Extension
This Montreal borough includes several types of dwellings: duplexes, triplexes, renovated plexes, apartments with flat roofs, semi-detached buildings, small co-properties, and townhouses. HVAC systems often need to be integrated into environments where margins for maneuver are limited.
For this project, several constraints had to be taken into account:
- access to the roof;
- membrane protection;
- stability of the outdoor unit;
- distance between the outdoor unit and indoor heads;
- routing of refrigerant lines;
- respect of clearances around the condenser;
- noise and vibrations;
- ease of access for maintenance;
- safe integration with other equipment present on the roof.
These constraints are not theoretical. They directly influence the quality of the installation and client satisfaction. A poorly positioned unit can become difficult to maintain, too exposed to wind, too close to an obstacle, or poorly protected against snow. Conversely, a well-planned installation offers better reliability and more consistent comfort.
Key steps in our intervention
For a DoubleZone heat pump installation on a roof, our team follows a structured method. Each step aims to reduce risks and guarantee a lasting result.
Analysis of interior needs
Before choosing head locations, we analyze the rooms to be served, air circulation, sun exposure, insulation, openings, and client habits. A good installation always begins with a precise understanding of the desired comfort.
Validation of the technical route
We then determine the best routing for refrigerant lines, cables, and drainage. In a Montreal building, this step is often the most delicate, as it requires working with the existing structure, walls, ceilings, access points, and external constraints.
Preparation of the outdoor support
On the roof, the outdoor unit must be installed on a stable base. In this project, the elevated structure helps protect the membrane, improve clearance, and facilitate future interventions. Supports are placed to distribute the load and limit vibrations.
Connection of the two zones
Each indoor head is carefully connected to the outdoor unit. Refrigerant connections must be clean, leak-tight, and conform to best practices. Adequate vacuuming is then performed to remove moisture and air from the system before commissioning.
Tests and startup
Once the system is installed, we check its operation in cooling and heating, the response of both heads, supply temperatures, communications between units, and the overall behavior of the machine. The client also receives the necessary explanations to use their system effectively.
The importance of not neglecting roof supports
The photo shows an aspect often invisible in quick quotes: the quality of the support. On a flat roof, it's not enough to simply place a unit on two blocks. The support must be stable, level, sufficiently robust, and compatible with outdoor conditions.
A good support contributes to:
- keeping the unit level;
- reducing vibrations;
- protecting the membrane;
- avoiding direct contact with water;
- facilitating cleaning around the unit;
- improving access for HVAC maintenance;
- extending the lifespan of the installation.
At AirGreen, we know that these details are an integral part of overall performance. A quality heat pump installed on an inadequate base risks generating avoidable problems. Conversely, a well-designed mounting promotes system stability for many years.
Performance and daily comfort
The GREE FREE MATCH R32 DoubleZone allows the client to manage two spaces with greater precision. In summer, the system can cool areas most exposed to heat. In spring and autumn, it can also contribute to supplementary heating, limiting the use of other heat sources when conditions allow.
Comfort is not limited to the temperature displayed on a remote control. It also depends on air distribution, noise levels, operational stability, and the system's ability to adapt to actual needs. A well-installed DoubleZone system offers a more nuanced response than a single unit placed in one room.
Subsidies and eligibility: an important check for clients
Homeowners installing a heat pump are often interested in available financial aid programs. For a multi-zone system like the GREE FREE MATCH R32, eligibility generally depends on the exact combination of the outdoor unit and indoor units, as well as the criteria applicable at the time of installation.
AirGreen assists its clients in understanding the necessary documents, including model numbers, detailed invoices, and relevant technical information. When the system is eligible, this preparation facilitates the process after installation.
Mistakes to avoid when installing a heat pump on a flat roof
Rooftop installation requires particular vigilance. Here are the mistakes we systematically avoid in our projects.
Placing the unit directly on the membrane
This can create wear, pressure points, and waterproofing problems. An adapted base is essential.
Neglecting vibrations
Even a modern unit can transmit vibrations if poorly supported. The choice of location and support directly influences acoustic comfort.
Blocking service access
A unit that is difficult to access complicates maintenance, diagnostics, and repairs. Future access must be planned from installation.
Poorly protecting refrigerant lines
On a roof, lines are exposed to weather, UV rays, temperature variations, and contact risks. Adequate protection is essential.
Underestimating wind and snow
Flat roofs are exposed. The location must take into account snow accumulation, wind, and surrounding obstacles.
AirGreen's expertise developed in Montreal's dense neighborhoods
AirGreen regularly carries out installations in urban areas where technical constraints are significant: Villeray, Saint-Michel, Parc-Extension, Rosemont, Plateau-Mont-Royal, Ahuntsic, Côte-des-Neiges, Hochelaga, Verdun, and several other sectors of Montreal. This experience allows us to offer realistic solutions for buildings with flat roofs, restricted access, and specific aesthetic or structural requirements.
We also work on similar projects in Laval, Longueuil, on the North Shore and the South Shore, where owners are looking for clean, reliable installations that are well adapted to their building's constraints.
This project in Villeray–Saint-Michel–Parc-Extension demonstrates our ability to combine performance, safety, and technical finishing. The outdoor unit is stably installed, the lines are carefully organized, and the DoubleZone configuration meets the need for indoor comfort without cluttering outdoor ground spaces.
A reliable, clean result adapted to Montreal's urban life
The final result is an HVAC installation designed to last. The GREE FREE MATCH R32 DoubleZone heat pump allows the client to enjoy better distributed comfort in two zones, while retaining a single outdoor unit installed on the roof. This approach is particularly relevant for buildings in Villeray–Saint-Michel–Parc-Extension, where courtyards, alleys, and side spaces do not always allow for a traditional installation.
At AirGreen, we place as much importance on the choice of equipment as on the quality of the assembly. The support, positioning, connections, line protection, access for maintenance, and commissioning are all essential elements. It is this rigor that allows us to offer a high-performance, durable solution adapted to the demands of Quebec's climate.
For owners considering a heat pump, a wall-mounted air conditioner, a DoubleZone configuration, an R32 installation, or HVAC maintenance in Greater Montreal, this achievement demonstrates the importance of entrusting the project to a team capable of understanding the building as a whole, from indoor comfort to the rooftop.