When persistent health symptoms continue despite every effort
In Longueuil, inside a commercial building housing medical offices and administrative services, several employees had been suffering for months from chronic allergy symptoms: irritated eyes, runny nose, recurring headaches, unexplained fatigue. After replacing wall-mounted air conditioner filters, hiring cleaning services, and even removing certain carpets, nothing worked. Even worse, three individuals on medical leave had all worked on the same floor.
That’s when the building manager contacted AirGreen to carry out a full assessment of the ventilation system, suspecting that indoor air might be the real issue. And he was absolutely right.
Thorough inspection: detecting hidden mold and stale air
During our technical audit, our team performed:
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Indoor air quality (IAQ) testing across various floors
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Air samples from existing ducts
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A full visual inspection of exhaust grilles, air returns, and ventilation motors
The results were conclusive:
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Presence of active mold spores in the exhaust air ducts
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No mechanical fresh air renewal in over 60% of enclosed zones
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Constant humidity levels above 65%, due to insufficient ventilation in windowless service areas
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Outdated filters, several years old and never adapted to the building’s actual airflow needs
A targeted solution executed without disrupting occupants
Knowing the building had to remain operational during the work, we developed a phased intervention plan, performed in the evenings and on weekends.
Here’s what we implemented:
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Installation of a Venmar EKO 1.9 air exchanger with heat recovery, designed for commercial buildings
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Addition of insulated rigid ducts to critical zones (break rooms, copy rooms, windowless hallways)
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Replacement of grilles and exhaust outlets with antibacterial models featuring integrated deflectors
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Complete duct cleaning and certified sanitation, including an antifungal treatment approved by Health Canada
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Installation of a CO2 detection system to automatically adjust airflow based on real-time occupancy
Tangible results in under 3 weeks
Barely three weeks after our intervention:
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All allergy symptoms disappeared, according to surveyed employees
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IAQ improved by 87%, based on data from our installed sensors
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Energy consumption dropped by 22%, thanks to the integrated heat recovery system
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The building is now compliant with BOMA BEST ventilation standards
A relieved building manager
“We had tried everything without ever thinking ventilation could be the root of the problem. AirGreen diagnosed it in less than 24 hours, then resolved everything efficiently. Since then, the complaints have stopped and the work atmosphere has greatly improved.”
Grants and assistance programs available
Our team also assisted the client in:
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Securing a $3,240 LogisVert grant for commercial ventilation improvements
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Obtaining a provincial tax credit for energy efficiency upgrades
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Preparing the full documentation for the Rénoclimat program, in collaboration with Longueuil’s local authorities
What this case reveals about ventilation in professional buildings
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Poorly ventilated indoor air can cause real health problems, even in modern buildings
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Air conditioning alone is not enough: active, controlled fresh air renewal is essential
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The absence of effective filtration or CO2 sensors is a long-term risk indicator
Why AirGreen is your trusted partner in Longueuil and across the South Shore
At AirGreen, we understand that every building has specific needs. Our mission is to protect the health of occupants while optimizing energy performance.
This project in Longueuil is far from unique. Every week, we intervene in clinics, offices, businesses, and public facilities to deliver ventilation solutions that are tailored, long-lasting, and compliant with the strictest standards.
Are you dealing with recurring complaints in your building? Employees getting sick for no apparent reason? Call AirGreen for a complete ventilation audit.
We respond quickly in Longueuil, Montréal, Laval, the North Shore, and the South Shore.