Poorly maintained ventilation can have serious—even tragic—consequences. In this real-life story that recently took place in Montreal, our team of HVAC experts at AirGreen was called for an urgent inspection of a home ventilation issue. What seemed like a routine check quickly turned into a critical safety intervention for an entire family. Here’s the detailed account of this delicate mission, the lessons learned, and how our expertise helped prevent a tragedy.
A strange smell in the house: the beginning of a cry for help
On a cold Tuesday morning, our customer service team received a worried call from a resident of the Villeray–Saint-Michel–Parc-Extension borough in Montreal. The family reported a persistent, slightly sweet odor throughout the home. They also mentioned recurring headaches, nausea, and unusual fatigue in their children, especially when spending extended periods indoors.
Our certified technicians immediately suspected a ventilation issue, possibly tied to a carbon monoxide (CO) buildup or poor air circulation. A team was dispatched to the site the same day.
Full inspection of the central ventilation system
Upon arrival, our experts carried out a complete assessment of the central ventilation system. This house, built in the 1980s, featured a ventilation setup connected to an air exchanger installed over 15 years ago. Very quickly, our technicians spotted excessive condensation, uneven air pressure across rooms, and most critically, a return air duct completely blocked by a bird’s nest and debris.
The invisible danger: carbon monoxide accumulation
The diagnosis was alarming. The blockage had severely impaired the air exchanger’s ability to renew indoor air. Even worse, a leak from a combustion heating appliance in the basement allowed carbon monoxide to slowly infiltrate the airflow system and accumulate in the upstairs rooms.
Using our professional digital CO detector, we recorded a concentration of 63 ppm in some areas—a level high enough to cause serious health symptoms over time, especially in children.
A rapid intervention to prevent poisoning
We immediately shut down the central ventilation system, installed a temporary portable ventilation setup, and advised the family to leave the premises during the cleaning and repairs. Our team then proceeded with a deep cleaning of the ductwork, removed the bird’s nest, and carried out a complete disinfection of the network.
We also replaced the outdated air exchanger with a high-performance, energy-efficient model, the Venmar AVS® N Series with ECM technology, offering outstanding energy savings—perfect for the harsh winters of Montreal, Laval, and Longueuil.
Maintenance tips to prevent CO poisoning risks
At AirGreen, we believe that proper HVAC maintenance is essential to protect the health and comfort of occupants. Here are a few key recommendations we share with our clients:
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Have your ventilation ducts inspected at least once a year.
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Install a certified, functioning CO detector on every floor.
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Replace old air exchangers with high-efficiency models.
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Clean grilles and filters every season.
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Always rely on certified professionals for installations or repairs.
A true story that shows how vital proper ventilation is
Thanks to a fast and professional intervention, no family members were seriously poisoned. But this case shows just how much a poorly maintained HVAC system can pose a serious health hazard. This Montreal family was able to return home safely and now enjoys clean, well-ventilated air every day.
Why choose AirGreen for your ventilation needs?
We serve all of Montreal, Laval, Longueuil, the North Shore and South Shore. Our technicians are trained to detect even the invisible flaws of a ventilation system, whether it’s related to humidity, mold, CO, or blocked ducts.
At AirGreen:
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We use professional diagnostic tools.
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We provide solutions tailored to the specific layout of your home or building.
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We work with trusted brands like Venmar, Aldes, and Lifebreath.
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We guarantee fast, safe, and lasting service, with custom advice.
Meticulous installations throughout the Greater Montreal area
Over the years, we’ve carried out ventilation system installations and cleanings in century-old homes in Outremont, new condos in Laval, and commercial offices in Brossard. Every time, our mission is the same: ensure exceptional air quality and protect the health of occupants.
Final word: ventilation is a matter of safety
Never underestimate the risks of faulty ventilation. If you notice an unusual smell, persistent symptoms, or your system hasn’t been inspected in years, call us immediately.
We’re here to protect what matters most: your health and your loved ones' well-being.