Understanding the hidden challenges of multizone installation in Montréal: local expertise, harsh climate, and costly mistakes to avoid
In Montréal, installing a multizone heat pump can radically transform the comfort of a home or commercial building. These systems, capable of heating and cooling multiple rooms with a single outdoor unit and several indoor units, are ideal for both older buildings and new constructions. However, behind this flexibility lie many hidden pitfalls that even some professionals overlook. At AirGreen, we’ve completed hundreds of multizone installations across Montréal, Laval, Longueuil, the North Shore, and the South Shore, giving us the experience to share crucial insights and help you avoid common mistakes.
1. Incorrect thermal load assessment: a pitfall with long-term consequences
An improperly sized multizone system can lead to poor performance, excessive energy consumption, and premature wear. Too often, installers underestimate or overestimate the actual needs of each zone.
Why this is critical in Montréal
Montréal’s climate is extreme, ranging from harsh winters to humid summers. A poorly sized multizone heat pump won’t provide consistent comfort or perform optimally during peak conditions. For example, during a recent installation in a duplex in Outremont, our team identified a miscalculation by a previous contractor: the system couldn’t adequately heat the basement. We corrected the installation by integrating a Fujitsu Multi-Zone AOU36RLXFZ unit with 36,000 BTU capacity, precisely adapted to each room following a complete thermal evaluation.
2. Choosing indoor units that don’t match room needs
Not all indoor units are created equal. There are wall-mounted models, floor consoles, ceiling cassettes, ducted units… but the choice should depend on the volume, insulation, use of the room, and desired aesthetics.
Real example: a customized setup in Laval
During a project in Laval-des-Rapides, our client wanted to cool a cathedral-ceiling living room, two bedrooms, and a basement office. A previous installer had recommended four standard wall units, which would have been ineffective for the high-ceilinged living room. At AirGreen, we proposed a four-way ceiling cassette for the living room and quiet Gree Multi-Zone Free Match wall units in the other rooms. The result: even temperature distribution and total client satisfaction.
3. Ignoring the technical limitations of the chosen multizone system
Some brands or models of multizone heat pumps have strict limits on piping lengths, vertical separation, or indoor unit combinations. Failing to respect these can void the manufacturer’s warranty and reduce the system’s lifespan.
Case study in Longueuil
A rental building in Longueuil had been equipped with a Bosch BOVA Multi-Zone system, but the installer exceeded the maximum allowed distances between units. The result: unusual noise, frequent breakdowns, and premature replacement. We had to redo the installation with a Mitsubishi Zuba Multi system, designed for longer piping runs, all while complying with the building’s electrical and structural standards.
4. Underestimating the complexity of multizone HVAC installation in existing buildings
Installing a multizone heat pump in an older Montréal home often involves accessibility issues, poor insulation, or low ceilings. Real expertise is required to properly integrate the piping without compromising aesthetics or efficiency.
A successful transformation in Plateau-Mont-Royal
In a century-old home, the wall space was too narrow to run refrigerant lines. Thanks to our experience, we proposed a hybrid solution: a Fujitsu AOU24RLXFZ outdoor unit paired with two wall units and one discreet recessed floor console, with insulated piping run along decorative baseboards. The client preserved their heritage style while enjoying modern comfort.
5. Overlooking available grants and long-term energy savings
Many homeowners are unaware of the financial assistance offered by Hydro-Québec and LogisVert programs for high-efficiency multizone heat pumps. Choosing a non-eligible model or submitting incomplete paperwork can result in a loss of up to $5,000 in incentives.
Our advice at AirGreen
We help every client choose a heat pump eligible for grants, such as the Zephyr MultiZone R32, known for its energy efficiency (up to 20 SEER). We also assist clients in putting together the grant application, with all required documentation and performance data.
Which multizone models should you choose in Montréal?
Here are some of the multizone heat pumps we regularly install with excellent results in the Greater Montréal area:
-
Fujitsu AOU36RLXFZ: up to 5 zones, efficient down to -25°C
-
Gree Free Match Multi-Zone: G10 Inverter technology, great for modern homes
-
Bosch BOVA Multi-Zone: ultra-quiet technology, ideal for condos
-
Mitsubishi Zuba Multi: built for the harsh Canadian climate
-
Daikin MXS Series: advanced connectivity and stable performance
Every project is unique. At AirGreen, our mission is to design a 100% personalized solution, tailored to the building’s specifics, the desired comfort level, aesthetics, and available budget.
Why choose AirGreen for your multizone installations in Montréal and surrounding areas?
With over 15 years of HVAC experience in Montréal, Laval, Longueuil, the North Shore, and the South Shore, we’ve built a solid reputation based on:
-
Accurate and transparent diagnostics
-
Proven technical expertise, even in complex cases
-
Administrative support for grant applications
-
Quick, clean, and code-compliant installations
-
Responsive and local after-sales service
Each multizone heat pump installation is a long-term commitment for us. We work with precision, integrity, and attention to detail to deliver sustainable, energy-efficient comfort to our clients.
Conclusion: Avoid the pitfalls, trust in real expertise
A multizone heat pump is an excellent investment to optimize the comfort of your home or business in Montréal. But its installation requires advanced technical expertise, local climate knowledge, and meticulous planning. At AirGreen, we guide you through every step, from product selection to installation and financial incentives. Don’t let these 5 hidden pitfalls compromise your comfort—trust our team for a reliable, clean, and high-performing HVAC multizone installation.