Renovating an old building in Montréal while integrating a modern multizone heat pump system can seem like a daunting, even discouraging task. However, at AirGreen, we’ve tackled this challenge time and again—with precision, expertise, and success. Thanks to our solid experience in HVAC system installations in heritage buildings, old triplexes, brick duplexes, and other iconic constructions in Montréal, Laval, Longueuil, the North Shore, and the South Shore, we know exactly how to respect the existing structure while meeting the technical demands of modern comfort.
The multizone heat pump is increasingly becoming a viable, efficient, and discreet solution for heating and cooling multiple rooms—without compromising the integrity of older buildings. That said, it’s critical to choose the right model, develop a flawless installation strategy, and work with a certified installer who understands the realities of Montréal’s unique architectural landscape.
What is a multizone heat pump, and why consider it in an old building?
A multizone heat pump powers multiple wall-mounted, ceiling-mounted, or floor console units from a single outdoor compressor. This setup is ideal for homes with several rooms needing independent temperature control, especially where ducted systems (often impossible in pre-1960 buildings) are not an option.
The main advantages:
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Individual temperature control in each zone.
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Ductless installation, making it less invasive for existing structures.
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Higher energy efficiency with models boasting high SEER/HSPF ratings.
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Eligibility for generous grants like Hydro-Québec’s LogisVert program.
Case study: Successful installation in a century-old triplex in the Plateau-Mont-Royal
One of our most technically complex projects was completed in a 1910 triplex located in the Plateau-Mont-Royal. The client wanted independent heating and cooling for all three floors—without damaging the original masonry or piercing decorative ceilings.
Challenges we encountered:
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Restricted backyard access for the outdoor unit.
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No possibility for visible ductwork.
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Outdated electrical panel requiring partial upgrades.
Our solution:
We proposed the installation of a GREE MULTI+ EXTREME multizone heat pump (36,000 BTU), paired with three 12,000 BTU Gree Lomo+ indoor wall units. With detailed planning, we:
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Optimized refrigerant line paths through existing closets.
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Executed all wall penetrations in non-visible areas.
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Eliminated outdoor unit vibrations using an anti-vibration platform.
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Coordinated with a master electrician to bring the panel up to code.
The result: a modernized heritage property with no aesthetic compromise and a significant reduction in heating costs.
Recommended brands for old buildings in Montréal
Not all heat pumps are suitable for the structural limitations of older buildings. Based on our hands-on expertise, here are a few models we regularly recommend at AirGreen:
Gree MULTI+ EXTREME (R410A or R32)
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Outdoor models up to 60,000 BTU, powering up to 5 zones.
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Compatible with various indoor unit formats.
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Ultra-quiet and designed to withstand Montréal’s harsh winters.
Fujitsu AIRSTAGE Multi (KXAH / KXLH)
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Inverter technology for consistent indoor comfort.
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Compact design ideal for Montréal’s narrow alleyways.
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Excellent SEER/HSPF seasonal efficiency.
Daikin MXL Series
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Discreet, reliable—perfect for condos or co-owned properties.
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Compatible with wall units and low-wall floor consoles.
What you need to know BEFORE installing a multizone heat pump in an old building
Be aware of municipal permits
In Montréal, many neighborhoods fall under Heritage Regulations. Outdoor unit installations can be restricted or subject to approval. At AirGreen, we help our clients submit plans and handle the administrative process with the City.
Importance of insulation
A heat pump is most effective in a well-insulated building. Before installation, we always recommend:
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A comprehensive energy assessment.
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Sealing of old windows.
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If necessary, adding insulation to interior walls or ceilings.
Planning the commissioning
The electrical system must support the compressor’s power draw. We always conduct a pre-installation electrical assessment, and our certified electricians handle all code-compliant upgrades if needed.
Available grants and incentives
Hydro-Québec’s LogisVert program
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Up to $2,500 in grants for an energy-efficient multizone heat pump.
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Eligible models include Fujitsu, Gree, Daikin, etc.
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Grant process fully handled by AirGreen.
RénoVert Tax Credit (if extended)
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Reimbursement of up to 20% of eligible expenses.
We support our clients from start to finish, from product selection to submitting the grant application.
Why choose AirGreen for this type of project?
At AirGreen, we don’t just install HVAC systems—we integrate them intelligently into complex environments. We know an old building in Montréal is not a brand-new condo in Brossard. Each project is carefully tailored.
Our advantages:
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A team of technicians specialized in heritage buildings.
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Clean, fast, and discreet installations.
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In-depth knowledge of the local market and government aid programs.
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Thorough post-installation support with annual preventive maintenance.
Conclusion: miracle solution OR well-managed technical puzzle?
A properly designed and installed multizone heat pump is not a headache—it’s a smart, long-lasting solution for modernizing old Montréal buildings. It’s not a luxury or a gamble. It’s a structured investment that adds comfort, increases property value, and preserves the soul of the building.
At AirGreen, we have the tools, expertise, and passion to turn every project into a success—no matter the age or complexity of your building.