Mastering Air Circulation for Optimal Comfort in Winter
The harsh Quebec winter puts every residential HVAC system to the test. In multi-storey homes, it's common for heating systems to distribute warm air unevenly, resulting in an overall feeling of discomfort. So-called “hot air bottlenecks” can form in certain areas — overheated zones on the upper floor and underheated rooms on the ground floor. At AirGreen, we’ve faced this challenge many times, and our work in homes across Montréal, Laval, Longueuil, the North Shore and the South Shore has helped us develop real, practical solutions to improve thermal distribution.
Understanding “Hot Air Bottlenecks”: A Physical and Technical Issue
Warm air naturally rises, which causes heat to build up on the second floor of homes. If your central heat pump or ventilation system isn’t properly calibrated, it creates major thermal imbalances. Here are the main symptoms of this issue:
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Excessive temperatures on the upper floor
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Cold rooms on the ground floor
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High energy consumption without added comfort
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Indoor units that seem ineffective or poorly positioned
At AirGreen, we encountered this exact issue in a single-family home in Boucherville (South Shore), where a 36,000 BTU Bosch BOVA central heat pump was installed without proper ductwork distribution. The result: the upper floor reached 25°C while the main living room barely hit 18°C, even with the system running constantly.
Case Study: Strategic Ductwork Adjustment in Laval
In a Laval home, our team was called in to assess a 3-ton Goodman central heat pump paired with an electric furnace. The homeowner reported that despite the thermostat being set at 21°C, the upstairs was excessively warm, while the basement and ground floor remained uncomfortable.
What We Did:
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Installed smart motorized dampers to modulate airflow in real-time
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Added a return air duct on the ground floor to improve thermal recirculation
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Fine-tuned the supply plenum to balance air pressure
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Installed a connected multi-zone thermostat for dynamic temperature control
Result: evenly balanced temperatures throughout the home, a 23% drop in energy consumption, and a noticeable increase in comfort.
Concrete Solutions to Prevent Thermal Imbalances
1. Redesign the Duct Network
Too often, ducts are oversized or poorly routed. It’s essential to optimize:
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Duct sizing based on the BTU output of the heat pump
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Air vent placement to ensure even airflow
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Static balancing to manually adjust each damper
2. Install a Heat Pump with Inverter Technology
Models like the Fujitsu KZAH R-32 or the Bosch IDS Premium R-454B automatically adjust their output based on real-time demand. This allows for:
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Better distribution of warm air
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Fewer start-stop cycles
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A reduction in temperature gaps
3. Integrate a Multi-Zone System
Adding a zoned system allows for independent temperature control on each floor. We recommend using smart connected thermostats compatible with variable-speed central heat pumps.
4. Use Adjustable Air Diffusers
Manually adjusting air vents can correct airflow issues without needing a full system overhaul. We always perform these adjustments during our HVAC maintenance services in Montréal and nearby areas.
The Importance of Maintenance: Preventing Heat Accumulation
A poorly maintained system can make hot air bottlenecks worse. In Saint-Eustache, our technician recently discovered that a clogged filter was restricting airflow to the ground floor. After a full HVAC system maintenance, temperatures balanced out with no need to replace any components.
At AirGreen, every maintenance visit includes:
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Coil cleaning
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Filter replacement
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Duct and plenum inspection
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Static pressure testing
Our Professional Recommendations for Multi-Storey Homes
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Choose equipment suited to the home’s structure (surface area, number of floors, orientation)
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Avoid single-zone systems in multi-storey homes
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Always include a return air duct on each level
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Favor Inverter compressor models for constant modulation
We’ve found that applying these best practices reduces hot air bottleneck complaints by over 80% in our installations.
Why Trust AirGreen
In Montréal, Laval, Longueuil, the North Shore and the South Shore, our team is known for its expertise in complex HVAC installations for older homes, modern builds, and multi-storey properties. Our field experience, combined with rigorous technical analysis of every project, allows us to tailor each installation to your real-world needs. Whether you choose a wall-mounted heat pump, a central heat pump, or a zoned system, we ensure warm air is evenly distributed — even in the heart of a brutal Quebec winter.