Improving indoor air quality while eliminating mold: a successful mission in Longueuil
In the quiet residential neighborhood of Longueuil, a couple of homeowners was facing a common yet often underestimated issue: persistent mold in their basement, not only causing unpleasant odors but also raising serious concerns about their own health and that of their children. The mold had resisted several cleaning attempts. That’s when they contacted AirGreen, specialists in residential ventilation on the South Shore, for a lasting solution. This project perfectly illustrates how a well-thought-out ventilation strategy can purify a space and prevent long-term structural and respiratory problems.
A common issue: humidity and inadequate ventilation
The basement in question wasn’t particularly old, but like many homes in Longueuil, it suffered from inefficient passive ventilation, especially during the summer months. The stagnant humidity, combined with poor air circulation, had encouraged mold growth on the walls and behind certain furniture. Several dehumidifiers had been installed in the past, but no system addressed the root of the problem: constant air renewal.
A tailored assessment: AirGreen’s indoor air quality diagnosis
Before any work began, our team visited the site for a complete air quality evaluation, using tools to measure relative humidity, mold spore concentration, and CO2 levels. This diagnosis revealed that:
-
Relative humidity was over 72%, a level highly favorable for mold growth.
-
Stale air was barely being renewed, especially in the deeper corners of the basement.
-
There was no independent mechanical ventilation system from the rest of the home.
Based on these findings, we designed a centralized air exchanger (HRV) system specifically adapted to the basement’s layout.
Technical choice: a high-performance and silent HRV air exchanger
We recommended the Venmar AVS N Series 120 CFM, an HRV model known for its energy efficiency, quiet operation, and ability to eliminate excess humidity while bringing in filtered fresh air.
Technical specifications of the installed unit:
-
Air exchange capacity: 120 CFM (cubic feet per minute)
-
Heat recovery efficiency: up to 70%
-
MERV 8 filtration, upgradeable to MERV 13
-
Compatible with programmable wall thermostat
-
Silent, ideal for basements used as living spaces
Strategic installation: discretion and efficiency
The installation was completed in a single day. Our technicians strategically placed the exhaust grilles in the most problematic areas (laundry corner, behind wall units, near the floating floor). Two fresh air inlets were installed, ensuring even distribution throughout the space. We paid special attention to the acoustic insulation of the main duct to ensure silent operation even at night.
We also integrated a Venmar Digital Control wall unit, allowing the clients to adjust the speed and schedule settings by season.
Measurable results: mold eliminated and comfort restored
A few weeks after the installation, a follow-up visit confirmed the system’s effectiveness:
-
Relative humidity is now stabilized between 45–50%.
-
No signs of new mold growth.
-
The air feels fresher, lighter, without stale odors.
-
The couple noted fewer allergy symptoms in their asthmatic child.
We also provided a full follow-up report, useful for home insurance and future evaluations.
Why mechanical ventilation is essential in basements
Long-term mold prevention
A basement without adequate ventilation quickly becomes a breeding ground for mold. These fungi not only damage building materials but can also affect occupants’ health, triggering allergies, irritations, or chronic respiratory problems.
The role of an air exchanger
An HRV air exchanger extracts stale, humid air and replaces it with fresh outdoor air while preserving thermal energy. It’s a doubly effective solution: thermal comfort and improved air quality, without a significant increase in energy costs.
AirGreen: your trusted ventilation expert in Longueuil and the South Shore
At AirGreen, we know that every project is unique. That’s why our solutions are always customized, based on detailed analysis, cutting-edge equipment, and above all, flawless execution by our certified technicians.
Our team serves Longueuil, Montréal, Laval, the North Shore, and the South Shore, for all your needs in HVAC installation, preventive maintenance, air purification, and humidity control.
Practical advice to keep a healthy basement
-
Regularly monitor relative humidity with a hygrometer.
-
Avoid carpeting in the basement, as it traps humidity.
-
Ventilate regularly, even by slightly opening windows.
-
Call a professional to evaluate your current ventilation system.
A concrete commitment to our clients’ health
We firmly believe that well-being starts with clean air. Projects like this one in Longueuil show that well-executed technical solutions can transform an unhealthy environment into a comfortable, functional, and safe space for the whole family.