One truth we know well in the HVAC field in Montréal is that behind every multi-zone heat pump installation, there are crucial details that very few professionals take the time to explain to the client. At AirGreen, we firmly believe that complete information, transparency, and real-world expertise are the keys to long-lasting and high-performing service. In this article, we reveal five secrets that most multi-zone heat pump installers prefer to keep to themselves — secrets that can make all the difference between a system that performs for 15 years… or one that breaks down after 3 winters.
A multi-zone system is powerful… but only if sized perfectly
One of the industry’s biggest secrets lies in the improper sizing of indoor and outdoor units. Many installers simply base their calculations on your home's square footage, without considering essential factors like:
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Sun exposure
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Actual insulation in walls and windows
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Thermal losses specific to each zone
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Ceiling height or natural air circulation
At AirGreen, we take the time to perform a full thermal analysis of your home in Montréal, Laval, Longueuil, the North Shore, and South Shore, to size each indoor unit based on the real needs of the room. An oversized unit will cause short cycles, uneven temperatures, and increased energy use. An undersized unit will run in overdrive and wear out prematurely.
Not all indoor units are compatible with each other
Another rarely mentioned point: wall units, ceiling cassettes, or floor consoles connected to a single outdoor unit must be rigorously compatible with one another and with the master unit’s output capacity. Some brands (like Fujitsu or Gree) offer better flexibility, while others have strict limitations.
For example, we encountered a case in Longueuil where a client wanted to connect four 12,000 BTU wall units to a 36,000 BTU outdoor heat pump. Problem? The manufacturer recommended a maximum load deviation of 25% between heads. Result? Poor performance, mechanical noise, and the manufacturer’s warranty was void. AirGreen replaced the entire system with a Fujitsu Multi Zone unit optimized with a 9k/12k/12k/18k setup, fully approved by the manufacturer.
The key to comfort: truly independent zone management?
Many clients believe that a multi-zone system allows for full independent control of each room. Technically true, but beware: if only one head is running, it can force the outdoor unit to operate at high capacity, even if it's just heating a small office. This reduces the system’s overall efficiency.
At AirGreen, we program progressive startup logic and smart modulation settings for each zone. The result: better energy performance and consistent comfort, even when multiple zones are being used unevenly.
Grants… but under what conditions?
Did you know that not all multi-zone installations automatically qualify for Hydro-Québec (LogisVert) subsidies or federal rebate programs? What most installers don’t tell you is that certain conditions apply:
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The outdoor unit must have a SCOP rating higher than 4.1
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Each indoor unit must meet a minimum efficiency threshold
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The installation must be completed by a contractor recognized by the program
AirGreen, being certified by all major financial assistance programs, helps you with submitting documents, equipment verification, and planning to maximize your eligible refunds — often between $1,700 and $5,000 for a high-efficiency multi-zone system.
A clean installation doesn’t guarantee a quiet system
Lastly, the final secret: noise doesn’t just come from the equipment, but from how it’s installed. Poor placement of refrigerant lines, lack of dampeners on wall brackets, or too rigid mounting in lightweight walls can cause:
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Wall vibrations
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Echoing in ductwork
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Buzzing sounds in bedrooms at night
Our installation teams in Montréal, South Shore, and North Shore use advanced soundproofing techniques: insulated ducts, anti-vibration foam, silent elbows, and floating mounts. That’s why our clients often tell us that our installations are among the quietest on the market.
Real-life examples of AirGreen multi-zone installations
Montréal - Plateau Mont-Royal: comfort in a century-old duplex
We installed a Gree Free Match multi-zone heat pump (36,000 BTU) with four wall-mounted units in a renovated duplex in the Plateau. The challenge? Solid brick walls, no crawl spaces, and a need to preserve historic charm. The result: hidden installation with ducts concealed in closets, no exterior moldings, and perfect comfort even at -25°C.
Laval - Fabreville: hybrid solution for a damp basement
In this semi-basement bungalow, we installed a Fujitsu multi-zone heat pump with a ceiling cassette in the living room, a floor console in the family room downstairs, and two wall-mounted units in the bedrooms. The system effectively dehumidified the basement, while maintaining a sleek look upstairs.
What we recommend to every potential customer
Before signing a multi-zone installation contract:
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Demand a room-by-room thermal evaluation
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Ask for a subsidy eligibility check
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Inquire about potential noise and vibration protections
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Make sure the proposed indoor heads are truly compatible
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Choose a company that explains everything… like we do at AirGreen
Why choose AirGreen for your multi-zone heat pump?
We’re not just equipment resellers. We’re your energy comfort partners. Our approach is based on analysis, transparency, field expertise, and personalized after-sales support. Thanks to our certified teams and seasoned technicians, we deliver a custom multi-zone system, reliable, high-performing, and eligible for the best rebates in Québec.