Clean, well-circulated indoor air is essential for both comfort and health. Yet in many homes throughout Montréal, Laval, Longueuil, the North Shore and the South Shore, subtle warning signs can indicate a failing ventilation system. These symptoms often go unnoticed or are misinterpreted, leading to a gradual decline in air quality and thermal comfort. At AirGreen, we’ve seen these situations many times, and we understand how a poorly functioning ventilation system can affect your daily life.
When air becomes invisible, the signs are not
It’s easy to assume everything is working fine as long as your HVAC equipment runs quietly without obvious issues. But subtle anomalies can reveal that your air exchanger is poorly adjusted, clogged, or simply not suited to your needs. Here are five overlooked symptoms that should immediately alert you to potential issues with your ventilation system.
1. Excess condensation on windows
This is often the first sign of excess indoor humidity, caused by inadequate air renewal. In winter, we frequently get calls from clients in Montréal and Laval concerned about their windows fogging up or dripping every morning.
In one Longueuil home, for instance, the installation of a new-generation Vanee air exchanger by our AirGreen team eliminated the issue in under two weeks. The previous unit was operating at just 30% of its capacity due to clogged filters and poor airflow calibration. Replacing it with a heat recovery ventilator (HRV) resulted in a complete improvement of the ambient air.
2. Lingering odors in certain rooms
A musty smell or cooking odors that persist for hours or even days point to stagnant air circulation. This means stale air isn’t being properly evacuated and that your air exchangers or ducts might be blocked or unbalanced.
In a home in Sainte-Thérèse on the North Shore, our team discovered a misconnected exhaust duct that caused cooking odors to stagnate in the open-concept kitchen. After reconfiguring the system and thoroughly cleaning the ducts, the odors completely disappeared.
3. Allergies, headaches, and unexplained fatigue
Poor ventilation fosters the accumulation of dust mites, mold, and fine particles. If you or your children experience persistent allergy symptoms, it could be a direct result of a malfunctioning ventilation system.
In Brossard, a family suffering from chronic migraines noticed significant health improvements after we installed a Lifebreath air exchanger equipped with a HEPA filter. Within a few weeks, measured air quality improved from poor to excellent, with a marked reduction in airborne particles.
4. Temperature differences from one room to another
Uneven temperatures between rooms can result from poor airflow distribution in your ventilation network. Often, this imbalance isn’t due to your heating or cooling system but to a poorly calibrated air exchange system.
We recently addressed this in a Repentigny property where the living room was always warmer than the bedrooms. Our inspection revealed jammed air dampers in the mechanical ventilation system. After adjusting them, airflow balanced out, and the client’s comfort level improved immediately.
5. Abnormal dust buildup
An inefficient ventilation system doesn’t renew indoor air properly, leading to excessive dust accumulation, especially on furniture and electronic devices.
On the South Shore, in a recently renovated home, our AirGreen team was called in for exactly this issue. Upon inspection, we discovered that the old air exchanger had been reinstalled without rebalancing the network. Installing a high-efficiency Zehnder air exchanger, along with precise rebalancing, resolved the dust problem while significantly improving air quality.
Why these signs should not be ignored
These mysterious symptoms are far from trivial. They often point to serious underlying issues in your ventilation system, which can result in:
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A significant drop in air quality.
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Increased indoor humidity, ideal for mold growth.
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Excessive energy consumption.
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A decline in your thermal and health comfort.
What we do at AirGreen
At AirGreen, we believe that ventilation is the silent heart of a healthy home. Our experts operate throughout Montréal, Laval, Longueuil, the North Shore and the South Shore to evaluate, repair, or replace failing ventilation systems, including HRV and ERV air exchangers, energy recovery ventilators, and centralized systems integrated into central heat pumps.
We work with trusted brands such as Venmar, Lifebreath, Zehnder, Fantech, and Aldes, and all our installations are custom-tailored, always preceded by a professional assessment of your specific situation.
Practical tips to maintain your ventilation system
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Clean or replace your air exchanger filters every 3 to 6 months.
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Have your ventilation network inspected by a professional at least once a year.
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Never block air intake or exhaust vents.
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Check the motor and airflow operation regularly.
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If you renovate, make sure your system matches the new indoor volume.
Conclusion: never underestimate the importance of ventilation
A failing ventilation system acts silently, but its impact on health, comfort, and your home’s integrity can be significant. If you notice one or more of these symptoms, it’s essential to consult certified professionals. At AirGreen, we put our HVAC expertise to work for your well-being. Whether it’s for a new air exchanger installation, preventive maintenance, or a complete upgrade, we act swiftly and efficiently to ensure clean, well-distributed air in every corner of your home.
Contact AirGreen today
Do you live in Montréal, Laval, Longueuil, on the North Shore or South Shore and suspect a ventilation issue? Don’t wait for the symptoms to worsen. Contact AirGreen for a free assessment of your ventilation system and breathe fresh, clean air again in your home.