A troubling reality has emerged in the residential sector across Montreal and its surrounding areas: an increasing number of new homes are showing serious shortcomings when it comes to ventilation. This phenomenon, which might seem paradoxical in an age of advanced energy standards, raises concerns for both homeowners and HVAC professionals. At AirGreen, we’ve encountered this issue time and again during our service calls in Montreal, Laval, Longueuil, the North Shore, and the South Shore. This article offers you an exclusive look, based on our real-world field experience, to help you understand the reasons behind this problem and the solutions we implement.
Brand-new homes, but stale air: a troubling contradiction
Most new homes built in Quebec comply with very strict airtightness standards to improve energy efficiency. But this increased insulation leads to an unintended consequence: a drastic reduction in natural fresh air intake. In other words, the home is so well "sealed" that it blocks natural air circulation. This can lead to:
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A buildup of CO₂ in closed rooms
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A rise in ambient humidity, creating ideal conditions for mold
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A stagnation of odors, allergens, and indoor pollutants
What we see in the field: the case of a home in Brossard
During a recent visit to a new home in Brossard, a couple contacted us because their children were experiencing frequent headaches with no obvious cause. After a comprehensive air quality diagnostic, we identified an abnormally high level of CO₂ caused by inadequate ventilation. The exhaust system installed by the builder wasn’t sufficient to ensure proper air renewal.
We recommended and installed a high-performance heat recovery ventilator (HRV), integrated with smart sensors. The result: immediate improvement in comfort, reduction in symptoms, and lower indoor humidity levels.
Why are ventilation systems often overlooked?
1. Pressure on construction costs
Home developers are under constant pressure to meet profit targets. Ventilation, often seen as a "secondary function" by some builders, is commonly reduced to bare-minimum or underperforming systems.
2. Lack of post-construction testing
Few developers conduct thorough air quality assessments after project completion. Homeowners typically discover problems months later, once signs of discomfort appear.
3. Lack of awareness about modern technology
Builders often stick to the basic systems required by the building code, without incorporating advanced solutions such as:
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Intelligent heat recovery ventilators (HRV/ERV)
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CO₂ sensors integrated with automated controls
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Airflow controllers and zoned ventilation systems
The invisible consequences of poor ventilation
Poor residential ventilation doesn’t just impact comfort—it affects health, building durability, and property value:
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Condensation on windows and material deterioration
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Mold growth, especially in basements
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Increased respiratory allergies, particularly among children
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Reduced performance of heating and cooling systems
Our customized solutions at AirGreen
At AirGreen, we take a tailored approach based on a full assessment of each home. Our HVAC ventilation experts serve Montreal, Laval, Longueuil, the North Shore, and the South Shore, bringing trusted expertise. Here’s a typical step-by-step of our process:
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Personalized ventilation audit: we measure airflow, humidity, CO₂, VOCs, and more
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Technical recommendations: we select a ventilation system tailored to the square footage, number of occupants, and architectural layout
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Installation of high-performance systems: we use brands like Venmar, Vanee, Lifebreath, or integrated central systems
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Calibration and balancing: precise adjustments to intake and exhaust outlets for optimal flow
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Client training: we provide practical advice on maintenance, filters, and control settings
Focus on a standout project in Laval
In a Novoclimat-certified home located in Laval, our team was called in to upgrade an existing ventilation system that was "code compliant" but insufficient. The challenge? A home with cathedral ceilings and an open-concept layout, creating dead zones with no air movement.
We installed a zoned ventilation system paired with a Venmar AVS HRV using an ECM motor. With a calibrated duct network, we eliminated stagnant air pockets. Smart sensors were programmed to adjust ventilation in real time based on occupancy and air quality.
Practical advice for new homeowners
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Don’t rely solely on code compliance. A system that’s “compliant” can still be far from optimal.
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Have your air quality tested at least once a year by a professional.
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Request centralized mechanical ventilation with heat recovery.
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Beware of relying only on bathroom exhaust fans—they’re not enough to ventilate an entire home.
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Change your HRV filters every 3 to 6 months.
Why trust AirGreen?
Our expertise is built on hundreds of successful installations, innovative solutions, and deep knowledge of the climate and housing realities in Montreal and its surroundings. Unlike companies that install generic systems, we take the time to understand each home in order to offer a tailored, long-lasting, and effective solution.