The importance of filters in a heat exchanger is often underestimated, yet they play a crucial role in the air quality we breathe inside our homes and buildings. At AirGreen, we’ve often noticed during maintenance or repair visits in homes across Montréal, Laval, Longueuil, the North Shore, and the South Shore that filters are neglected—sometimes forgotten for several years. This simple oversight can have significant consequences on the performance of the HVAC system, indoor air quality, and even the health of the occupants.
Why Are Heat Exchanger Filters So Critical?
A heat exchanger’s primary function is to renew indoor air while retaining thermal energy, thanks to a heat recovery system. The filter, on the other hand, acts as a barrier, preventing fine particles, pollutants, dust, pollen, and other contaminants from entering the system or being redistributed throughout the rooms.
A clogged or worn-out filter compromises this process in several ways:
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It reduces air circulation, which strains the fan motor.
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It increases the system’s energy consumption.
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It compromises heat exchange efficiency.
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It lowers air quality, promoting humidity, mold, and allergens.
Different Types of Filters: Which One Is Right for Your System?
During our HVAC inspections throughout the Greater Montreal area, we notice that many customers don’t know which type of filter their heat exchanger is equipped with. However, each system has specific needs. Here are the main types:
Foam Filters (Washable)
Common in basic models, they are economical and reusable. However, their filtration capacity is limited. They need to be washed monthly and replaced every 6 to 12 months.
Pleated Filters (Disposable)
These offer better efficiency thanks to a larger filtration surface. It’s crucial to choose a filter compatible with your unit’s airflow. Too dense, it will slow the system; too porous, it won’t filter anything.
HEPA Filters
Used in very sensitive environments (clinics, daycare centers, etc.), they block 99.97% of 0.3-micron particles. However, their use requires proper ventilation, as they significantly reduce airflow.
At AirGreen, we always perform a technical evaluation before recommending a filter because a poor choice can do more harm than good.
Recommended Maintenance Frequency
Depending on the seasons and environment (urban, forest, near highways, etc.), the frequency of cleaning or replacing the filter varies. Here are our practical recommendations:
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Every 1 to 3 months: visual inspection of the filter.
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Every 3 to 6 months: cleaning or replacement.
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More often if: you have pets, are smokers, or live near an industrial area or major traffic routes.
During our visits to Laval, Longueuil, or the South Shore, it’s not uncommon to find filters that haven’t been maintained in over a year—an error we immediately correct with a full system upgrade.
Signs That Your Heat Exchanger Filter Needs Changing
There’s no need to wait for a breakdown to act. Here are the common indicators:
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Persistent odors in the house
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Increased dust on furniture
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Weak or nonexistent ventilation
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Excessive humidity
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Unusual noise from the ventilation motor
At AirGreen, our technicians are trained to diagnose these issues quickly during annual maintenance.
Case Study: A Neglected Heat Exchanger in Sainte-Thérèse (North Shore)
A customer contacted us about persistent condensation and mold issues in their bathroom. During our inspection, we found a heat exchanger running at only 20% of its capacity… The filter hadn’t been replaced in 4 years.
After a full cleaning, replacing the filter with a high-efficiency pleated model, and adjusting the airflow, we restored proper circulation. Within 48 hours, the humidity problems disappeared.
Expert Tips to Avoid This Mistake
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Write the filter replacement date directly on the housing.
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Use a digital calendar or reminder alert every 3 months.
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Avoid low-quality universal filters, which are often ineffective.
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Call a professional to check the filter’s compatibility with your unit.
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Schedule an annual HVAC maintenance, including a check-up of the heat exchanger and duct system.
Why Choose AirGreen for Your Heat Exchanger Maintenance?
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Fast and professional service in Montreal, Laval, Longueuil, North Shore, and South Shore.
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Expertise in Venmar, Vanee, Lifebreath, Fantech, and other brands of heat exchangers.
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Detailed reports after each visit, including photos, recommendations, and technical sheets.
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Personalized advice on the ideal filter type based on your needs.
We don’t just replace a filter: we optimize your entire HVAC system to be both efficient, energy-saving, and durable.
Conclusion: A Neglected Filter, A Compromised Comfort
Ignoring heat exchanger filters jeopardizes the occupants' health, reduces system efficiency, and wastes energy. At AirGreen, we believe every installation deserves intelligent, preventive maintenance.
Whether you’re in Montréal, Laval, Longueuil, or anywhere in Greater Montreal, we’re here to help make your environment healthy, comfortable, and efficient.
Call us today to schedule customized HVAC maintenance. Your comfort deserves more than a forgotten filter.