Urban construction sites: an invisible threat to indoor air quality
In Longueuil, as elsewhere on the South Shore, construction projects are on the rise. Large residential developments, road infrastructure upgrades, major renovations—these projects not only alter the visual environment but also degrade the surrounding air quality. Fine dust, airborne particles, diesel fumes from heavy machinery… These pollutants easily make their way into nearby buildings, jeopardizing the respiratory health and comfort of occupants, especially when the ventilation system isn’t designed to handle this type of environmental stress.
At AirGreen, we were recently commissioned to protect a residential building located less than 15 meters from a large construction site in Longueuil. The challenge: ensure healthy indoor air despite extreme outdoor pollution levels.
Initial assessment: fine particles, noise, air pressure imbalance, and widespread discomfort
The building consisted of 18 residential units across three floors. During our first inspection, several issues stood out:
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Infiltration of PM2.5 and PM10 fine particles through existing air intakes.
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Outdated mechanical ventilation system, unable to filter urban pollutants.
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Baseboard heaters circulating unfiltered air, contributing to dust recirculation.
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Frequent complaints from tenants: itchy eyes, dry throat, headaches, diesel odors.
This was an urgent case. Without immediate intervention, there was a high risk of mold development and worsening respiratory symptoms, especially among seniors and children living in the building.
Our solution: a sealed, filtered, and calibrated HVAC ventilation system
AirGreen proposed a comprehensive, multi-step approach to actively and continuously manage air quality:
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Replaced the central ventilation system with a high-efficiency HRV unit, model Venmar EVO5 500 HRV, capable of handling airflow for the entire building.
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Installed MERV 13 filters at every fresh air intake, capturing up to 90% of fine particles.
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Added indoor air quality sensors (CO₂, VOCs, PM2.5) connected to a smart management platform.
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Created positive air pressure systems in hallways and stairwells to prevent dust from seeping in through gaps.
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Sealed off old wall registers and installed airtight air diffusers for better filtered air distribution.
Fast, coordinated installation with zero disruption for residents
One major challenge was carrying out this work without displacing tenants or affecting their comfort. We therefore planned:
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Drilling and ductwork replacements on weekdays between 9 a.m. and 3 p.m., during off-peak hours.
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A team dedicated to protecting the premises (carpets, walls, shared furniture).
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Regular communication with the property manager, keeping residents informed every step of the way.
In 12 business days, the new system was fully operational, with measurable results within the first few hours.
The results: restored comfort, pollutants eliminated, total satisfaction
Here are the benefits observed within 30 days of installation:
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85% reduction in PM2.5 and PM10 levels indoors.
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Significant improvement in indoor air odor, previously tainted by nearby construction.
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Noticeable drop in allergy symptoms reported by residents.
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Lower energy consumption, thanks to the HRV’s efficient heat exchange between incoming and outgoing air.
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Increase in tenant satisfaction, with fewer complaints sent to building management.
Why this approach is now essential in Longueuil and beyond
Environmental standards may be evolving, but today’s urban reality already demands HVAC systems that can handle sudden or prolonged outdoor pollution events. Buildings near construction zones, major roads, or industrial areas must:
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Actively control their air quality.
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Filter fine particles and irritant gases.
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Maintain balanced humidity, even with windows closed.
At AirGreen, we integrate these priorities into every project from day one.
Maintenance tips to keep your system efficient in urban settings
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Replace MERV 13 filters every 3 months during active construction periods.
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Inspect ductwork seals twice a year.
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Clean air diffusers regularly, especially at ground level.
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Monitor air quality alerts from sensors, to respond quickly when pollutants spike.
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Schedule a full professional maintenance service once a year, performed by our expert technicians.
AirGreen: your HVAC expert for complex urban environments
This Longueuil project perfectly illustrates our ability to respond quickly, design custom systems, and deliver clean air—even in highly exposed contexts. Thanks to our mastery of advanced ventilation technologies and our dedication to occupant comfort, we are the trusted HVAC partner for residential, commercial, and community buildings throughout Greater Montréal.