A worsening situation in a residential building in Laval
A few months ago, our team at AirGreen received an unusual call. In a residential building in Laval, several residents on the same floor were complaining about persistent bad odours spreading into the hallways and even some private units. More than just unpleasant, the situation had sparked growing tensions between neighbours, finger-pointing, and a heavy atmosphere throughout the building.
With the building manager unresponsive, one of the tenants reached out to us for a complete ventilation inspection. What started out as a simple evaluation quickly turned into a strategic and complex HVAC intervention, where our expertise truly made the difference.
A precise diagnosis: pollutant build-up and faulty ventilation
Upon arrival, our technicians conducted a comprehensive indoor air quality analysis. The results? High concentrations of VOCs (volatile organic compounds), trapped stale air, and virtually no airflow in certain ducts. The mechanical ventilation system, over 20 years old, was partially clogged with dust, grease, and even mould in some sections of the network.
The critical issues we identified:
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No effective air extraction in the shared bathrooms
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Cooking smells spreading between units
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High humidity levels in the horizontal ductwork
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An outdated HRV (heat recovery ventilator) with no functioning filters
This kind of scenario is common in Laval buildings from the 1990s, where HVAC maintenance has often been neglected for decades.
A custom AirGreen solution: replacement, deep cleaning, and air balancing
To restore healthy air circulation, our team proposed a three-step intervention plan, which was unanimously approved by the co-owners.
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Replacement of the central ventilation system
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Installation of a new Venmar EVO5 700 HRV, energy-efficient and compatible with the existing ductwork.
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This model was chosen for its 108 CFM capacity at low pressure—ideal for a mid-sized building.
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Includes MERV-13 filters for optimal filtration of allergens and fine particles.
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Complete duct cleaning
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High-pressure disinfection of all vertical and horizontal ducts.
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Application of an antifungal and antibacterial treatment to eliminate any traces of mould.
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Industrial vacuuming with rotating head in each section of the system.
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Airflow rebalancing and adjustment
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Accurate readings taken with a digital anemometer
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Adjustment of supply and exhaust vents to ensure even airflow across all units
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Installation of backdraft dampers wherever odour backflow had been identified
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Concrete results: purified air, harmony restored
Just days after the intervention, the results were immediate: the odours had completely disappeared, airflow was smooth throughout, and neighbour complaints vanished. One co-owner told us:
“We had almost gotten used to the smell, but it wasn’t until it was gone that we realized how unbearable it was. Thank you to the AirGreen team for your efficiency and respect.”
This type of feedback is the best proof that air quality directly affects quality of life, and that HVAC maintenance is a crucial investment.
Why this kind of intervention is critical in Laval
Laval, as a city experiencing rapid residential densification, is full of multi-unit buildings with shared ventilation systems. When a central system malfunctions, it doesn’t just affect one unit—it impacts an entire community. In a world where pandemics have heightened awareness around air quality, these issues have taken on even greater importance.
At AirGreen, we believe every building deserves a high-performance, well-maintained, and eco-friendly HVAC system. Our regional expertise—from Laval to Montréal, through Longueuil, the North Shore, and the South Shore—means we deliver solutions tailored to local realities.
What you can do if you suspect a similar problem
Here are the most common signs of a ventilation issue in a multi-unit building:
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Persistent odours circulating between units
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Constant humidity in certain rooms (bathrooms, kitchens)
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Visible or recurring mould
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Stale or uncomfortable indoor air
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Unusual noises in the ducts
Practical tips:
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Have your ducts inspected at least every 5 years
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Clean HRV filters every season
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Never block supply or exhaust vents
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Consult an expert before making any changes to your system
Conclusion: a simple call, a collective transformation
AirGreen’s intervention in Laval is a concrete example of our human, technical, and sustainable approach to HVAC. This wasn’t just a technical issue—it was about repairing social bonds between neighbours. Thanks to our work, the indoor climate—both literally and figuratively—was restored.
At AirGreen, we understand that every service call is unique, and that every ventilation system has its story. Maybe it’s time we help transform yours too.
Contact us today
Are you located in Laval, Longueuil, Montréal, or on the North or South Shore and suspect a ventilation issue in your building? Reach out to our HVAC experts for a comprehensive evaluation. At AirGreen, we bring fresh air back into your spaces… and peace back into your community.