Furnace filters play a crucial role in maintaining indoor air quality by trapping dust, pollen, pet dander, and other airborne particles as air circulates through your heating and cooling system. Here’s how furnace filters contribute to indoor air quality and what to consider when selecting one:

How Furnace Filters Improve Indoor Air Quality


  1. Particle Filtration: Filters capture various particles, including dust, pollen, mold spores, and pet dander, preventing them from being recirculated into your living spaces.
  2. Protecting HVAC System: By keeping debris out of the HVAC system, filters help maintain efficient operation and prevent system wear and tear, which can indirectly improve air quality.
  3. Reducing Allergens: High-efficiency filters can reduce allergens in the home, which is particularly beneficial for individuals with allergies or respiratory conditions.
  4. Minimizing Odors: Some advanced filters are designed to reduce odors from cooking, pets, and smoke.

Types of Furnace Filters


  1. Fiberglass Filters: These are the most basic and inexpensive filters. They capture large particles but are less effective at capturing smaller particles.
  2. Pleated Filters: Made from polyester or cotton, these filters have more surface area and can capture smaller particles than fiberglass filters.
  3. High-Efficiency Particulate Air (HEPA) Filters: These filters can trap 99.97% of particles that are 0.3 microns or larger. However, not all HVAC systems are compatible with HEPA filters due to their density.
  4. Electrostatic Filters: These filters use an electric charge to attract and capture particles. They can be washable and reusable.
  5. Activated Carbon Filters: These filters are effective at removing odors and volatile organic compounds (VOCs) in addition to particles.
Factors to Consider When Choosing a Furnace Filter


  1. MERV Rating: The Minimum Efficiency Reporting Value (MERV) rating indicates a filter’s ability to capture particles. A higher MERV rating means better filtration but can also restrict airflow if not compatible with your system. Common household filters typically have a MERV rating between 8 and 13.
  2. Filter Size: Ensure you get the correct size filter for your furnace. Using the wrong size can reduce efficiency and effectiveness.
  3. System Compatibility: Check your HVAC system’s specifications to ensure it can handle the filter type and MERV rating you choose.
  4. Replacement Frequency: Regularly replacing or cleaning filters is essential. Most filters need to be replaced every 1-3 months, but this can vary based on the type and usage.

Maintenance Tips

  1. Regular Inspections: Check your filters monthly to see if they need replacing.
  2. Follow Manufacturer Guidelines: Always follow the manufacturer’s recommendations for filter replacement or cleaning.
  3. Keep the Area Clean: Regularly clean the area around your furnace to reduce dust and debris that can get into the system.
  4. Professional Maintenance: Schedule annual maintenance checks for your HVAC system to ensure it is operating efficiently.

By choosing the right furnace filter and maintaining it properly, you can significantly improve your indoor air quality and create a healthier living environment.

Filters, one of the most expensive category for maintaining your system is your filter. How to choose it. We must look at two factors,restriction of air flow and filter efficiency.

Calgary filters

MERV 4 Efficiency <20%

Polen, Dust,

Particle Size >10pm

Minimal filtration

Filter merv 8

MERV 8 Efficiency 30-35%

Mold, Hair Spray

Cement Dust

Particle Size 3.0-10.0 pm

Filter Merv 11
MERV 11 Efficiency 60-65%

Legionella, Humidifier dust

Milled Flour, welding fumes

Better  filtration

Merv 16
MERV 16 Efficiency >95%

All Bacteria, Tabaco smoke

Superior filtration

Particle Size .30-1.0 pm


Is important to keep it clean,  to have less restriction and to protect your blower motor and to keep your indoor air clean. Dirty filters will have more resistence on air flow and the blower motor will overheat. As a result after long period of time, blower motor can broke early.

FiltersHEPA Filtration system is high efficiency system up to 99.97%. Is designed for removing particles and bioaerosols down to 0.3 micron. Particle like virus, carbon dust, combustion smoke. HEPA system it is a sealed bypass design which traps particles and prevents them from escaping.