Extreme Installations Mastered: AirGreen Expertise Bringing Multizone Comfort Even in the Heart of Winter
At AirGreen, we know that thermal comfort doesn’t take a break when winter hits hard. In a climate like Greater Montreal, where winter temperatures can easily plunge below -25°C, installing a multizone heat pump becomes a major technical challenge. But it’s precisely in these extreme conditions that our HVAC expertise truly shines.
This article takes you behind the scenes of a complex winter installation led by our team on the North Shore of Montreal, where we installed a high-performance multizone heat pump in the middle of January. Discover real on-site realities, the solutions we implemented, technical specifications of the system installed, and the mistakes to avoid if you’re planning a similar project.
Understanding the Multizone Heat Pump: A Tailored Solution for Personalized Comfort
A multizone heat pump allows several indoor units to be connected to a single outdoor compressor, with each indoor unit independently controlling the temperature of its own zone. This system is ideal for large multi-level homes, duplexes, or homes with finished basements.
Main Benefits:
-
Independent temperature control in each room
-
Significant reduction in energy consumption
-
Saves outdoor space with only one compressor
-
Eligibility for major government rebates, such as Hydro-Québec’s LogisVert program
Case Study: Multizone Heat Pump Installation in Blainville at -25°C
This past January, a client from Blainville contacted us to upgrade his aging heating system. He wanted to replace his electric baseboards with a more efficient solution while maintaining individual temperature control in his main rooms: living room, master bedroom, home office, and basement.
Equipment Selected:
-
Brand: Gree
-
Model: Gree Multi21+ Extreme
-
Capacity: 36,000 BTU outdoor / 4 indoor units of 9,000 BTU each
-
Refrigerant: R-32, for optimized performance and reduced environmental impact
-
Energy Efficiency: SEER 22, HSPF 11
-
Rebate Received: $2,848 through LogisVert
Technical Challenges of Winter Installations
Working at -25°C requires specific precautions, both for the safety of our technicians and for the performance of the heat pump itself. Here are the main challenges we faced:
1. Preparing the Site in Snow
Even before installing the compressor, we had to manually clear the outdoor area, install a raised platform for the compressor (40 cm above ground), and protect all lines from freezing. We also built a protective cover over the compressor, essential to prevent ice build-up.
2. Running Refrigerant Lines Through Frozen Walls
Drilling through walls at -25°C demands millimetre-precision. Our teams use heated hole saws to prevent cracking fragile, cold materials. Every line is insulated with high-density Armaflex foam, and wall exits are carefully sealed with UV-rated caulking.
3. Calibrating the Heat Pump in Extreme Temperatures
Unlike summer startups, a winter-installed heat pump requires additional fine-tuning: refrigerant pressure, defrost mode, outdoor fan speed, and antifreeze sensor calibration. Using our digital diagnostics tools compatible with Gree systems, we fine-tuned every parameter based on real-time winter conditions.
Results: Instant Comfort and Long-Term Savings
Right after the system went live, the client noticed evenly distributed comfort throughout the home. Thanks to the auto-restart function, the system automatically adjusts to temperature fluctuations—even in the event of temporary power outages.
Results observed after 2 months:
-
38% reduction in Hydro-Québec bill
-
Zero noise complaints (indoor unit sound level: 21 dB)
-
Stable temperatures even during a February cold snap at -27°C
Mistakes to Avoid When Installing a Multizone Heat Pump in Winter
We often see poorly done installs by less experienced contractors. Here’s what you must absolutely avoid:
-
Installing the compressor directly on the ground without elevation: snow and ice will accumulate and cause issues.
-
Skipping the protective cover: this small detail is crucial for the compressor’s longevity.
-
Failing to properly insulate copper lines: in winter, this results in performance drops and energy loss.
-
Incorrect placement of indoor units: bad angles or improper heights can block airflow distribution.
Why Choose AirGreen for Your Multizone Projects?
At AirGreen, we combine HVAC engineering, field experience, and unmatched customer service. Our installations are guaranteed, certified, and meet all current performance and safety standards. Plus:
-
We assist you in getting your rebates
-
We plan your projects even in winter with no downtime
-
We offer fast, personalized after-sales service
Other Multizone Installations by AirGreen
-
Saint-Lambert (South Shore): 5-zone install with Bosch Climate 5000 heat pump
-
Laval-des-Rapides: Full energy renovation project with Fujitsu KWL multizone heat pump
-
Outremont (Montreal): Triplex upgrade with ultra-quiet Zephyr 4-zone solution
Practical Tips to Properly Plan Your Multizone Project
-
Get a room-by-room thermal evaluation before choosing unit capacity.
-
Make sure installation is done by a certified contractor to qualify for rebates.
-
Research winter performance conditions of each brand before purchasing.
-
Always ask for a 10-year parts and labour warranty at minimum.
What Our Blainville Client Had to Say
“I didn’t think it was possible to install such a high-performing heat pump in January. The AirGreen team handled everything: planning, rebates, installation, and startup. Today, my whole home is warm and I’m saving money. Thanks again!”
In Summary: A Reliable Multizone Installation, Even at -25°C
Installing a multizone heat pump in winter isn’t a myth — it’s our everyday reality at AirGreen. Thanks to our expertise, professional tools, and rigorous methods, we turn every project into a long-term success.
For any HVAC multizone project in Montreal, Laval, Longueuil, on the North Shore or South Shore, trust AirGreen: we turn thermal comfort into reality, even in the snow.