The first line of defense against viruses, allergens, and indoor pollution is hidden in your HRV or ERV system
When it comes to respiratory health, most people think of medication, outdoor air quality, or lifestyle habits. But there’s one small, discreet component playing a major role in protecting your lungs: the filter in your air exchanger.
At AirGreen, we’ve seen through hundreds of service calls across Montreal, Laval, Longueuil, the North Shore, and the South Shore that neglecting or choosing the wrong filter in an HRV or ERV system can significantly increase the risk of respiratory illnesses. On the flip side, a well-selected and properly maintained filter becomes a powerful, accessible, and often overlooked health shield.
What a good air exchanger filter actually blocks
Contrary to popular belief, an air exchanger doesn’t just “move air around.” When paired with a quality filter, it can capture and trap invisible airborne particles that would otherwise make their way straight into your lungs.
A good filter removes:
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Fine dust and airborne particles (PM2.5 and PM10)
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Mold spores
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Pollen and plant allergens
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VOCs (volatile organic compounds) from building materials and household products
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Bacteria and viruses (to some extent, depending on the filter type)
The filter’s job is not only mechanical but also preventive, by continuously limiting your exposure to respiratory irritants.
Real-life example: A Laval family protected by a simple filter replacement
Ms. Gagnon, a resident of Sainte-Rose, contacted us last fall after both her children began experiencing frequent asthma attacks since moving into their new home. The house was well insulated and equipped with an HRV installed eight years prior—but the filter had never been changed.
Our team conducted an inspection and found the filter completely clogged with dust, pet hair, and even visible mold. After a full cleaning and replacement with a MERV 13 filter, the results were immediate:
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No more nighttime asthma attacks after just two weeks
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Less reliance on inhalers
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Overall improvement in indoor air quality, as confirmed by our monitoring tools
Choosing the right filter: what you need to know
Not all filters are created equal. Understanding filtration levels is key to selecting the right one for your needs:
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MERV 8: Basic filtration—captures dust, pet dander, and pollen
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MERV 11: Intermediate filtration—adds mold spores and some bacteria
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MERV 13: High-efficiency filtration—effective against fine particles, some viruses, and smoke
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HEPA filters: Very high-performance filtration, but require compatible systems and more frequent maintenance
Using a filter that’s too dense in an incompatible system can reduce airflow. That’s why a professional evaluation is always recommended.
Signs your filter is no longer doing its job
It’s not always obvious when it’s time to replace your filter. Here are some key warning signs:
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Excessive dust buildup in your home despite regular cleaning
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Persistent odors or a “stuffy” feel in the air
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Respiratory symptoms (coughing, itchy eyes, dry throat)
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Unusual noise or weakened airflow from your HVAC system
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Visibly grey, stained, or warped filter
At AirGreen, we recommend changing your filter every 3 to 6 months, depending on your environment, pets, and the sensitivity of occupants.
The direct link between filters and respiratory illnesses
Multiple Canadian studies have confirmed a direct correlation between indoor air quality and chronic respiratory illnesses, including:
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Asthma
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Chronic bronchitis
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Recurring sinus infections
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Seasonal allergies
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Worsening of long COVID symptoms
A properly maintained filter acts as your first line of defense, significantly lowering exposure to these disease triggers.
HVAC installation: integrating filters for optimal performance
During our HRV or ERV installations—whether in Montreal, Laval, or Longueuil—we take into account:
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The square footage of the home
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The number of occupants
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The presence of children, elderly individuals, or asthma sufferers
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Daily lifestyle factors (pets, smoking, frequent cooking)
We always recommend and supply a filter that matches your needs, and we offer HVAC maintenance contracts that include scheduled filter replacements.
AirGreen’s practical tips
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Mark the date of your filter change on the unit or a calendar
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Avoid cheap, uncertified filters from big box stores
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Ask our technicians for a certified MERV 13 or higher filter, if your system allows
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Don’t forget to clean or replace filters in your other HVAC systems: heat pump, wall-mounted AC, electric furnace
Conclusion: One small component, one huge impact
In the world of residential HVAC, the air exchanger filter is often overlooked. Yet it represents an essential health barrier against respiratory illnesses—especially in areas where indoor air is often more polluted than outdoor air, as is often the case in Montreal and the South Shore.
At AirGreen, we believe that a high-performing, well-filtered, and well-maintained system is more than just comfort—it’s a long-term health guarantee for your entire family.
Contact us today for a free evaluation of your HVAC system and filters.