Dustin Hufsey,
Proudly Serving the Mohave County Area.
Proudly Serving the Mohave County Area.
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Dustin Hufsey,

HVAC Filters Exposed: What You’re Not Being Told

Understanding HVAC Filters

Did you know that HVAC filters are essential for maintaining your system’s air quality and efficiency?

These filters are essential components of your HVAC system, designed to trap dust, dirt, pollen, and other airborne particles, preventing them from circulating through your home.


A Woman Thinking About HVAC Filters on a White Background
Photo from iStock – Credit: Wavebreakmedia

What Are HVAC Filters?

HVAC filters come in various types, each with unique characteristics that cater to different needs. Common types include:

  • Fiberglass Filters: These are the most basic and affordable options, primarily used to protect the HVAC system from large particles. However, they offer minimal air filtration and need frequent replacement.
  • Pleated Filters: Made from polyester or cotton paper, pleated filters have a larger surface area due to their folded design. This allows them to capture more particles, making them more effective than fiberglass filters.
  • Electrostatic Filters: These filters use self-charging fibers to attract and capture airborne particles. They are available in both disposable and washable versions, providing a balance of cost-efficiency and effectiveness.
  • HEPA Filters: Known for their high efficiency, HEPA filters can capture particles as small as 0.3 microns. However, they are not typically used in standard HVAC systems due to their restrictive airflow.


Importance of HVAC Filters

Why are HVAC filters so important? 

They serve two primary functions: improving indoor air quality and enhancing the efficiency of your HVAC system. 

Here’s how:

  1. Air Quality Improvement: By capturing pollutants such as dust, pollen, mold spores, and pet dander, HVAC filters help reduce allergens and contaminants in the air, making it safer and more comfortable for your family.
  2. System Efficiency: A clean filter ensures proper airflow through your HVAC system. When filters are clogged with debris, the system has to work harder to circulate air, which can increase energy consumption and utility bills.

Regular maintenance and timely replacement of HVAC filters are vital to keeping your system running efficiently and maintaining a healthy indoor environment. 

Neglecting filter changes can lead to a host of problems, from higher energy costs to potential damage to the HVAC system itself.


Types of HVAC Filters and Their Effectiveness

Fiberglass Filters

Fiberglass filters are the most basic and economical type of HVAC filters. 

Typically, they are made from layered fiberglass fibers and are designed primarily to protect the HVAC system rather than improve indoor air quality. 

These filters are about 1 inch thick and are effective at trapping large particles such as dust and debris. 

However, they are not very efficient at capturing smaller particles like pollen and pet dander, making them a less ideal choice for households with allergy sufferers or pets.


  • Cost-effective: Fiberglass filters are inexpensive and widely available.
  • Protects HVAC System: They prevent large particles from entering and damaging the HVAC system.


  • Low Efficiency: They have a low Minimum Efficiency Reporting Value (MERV) rating, usually between 1 and 4, indicating poor performance in filtering smaller particles.
  • Frequent Replacement Needed: Due to their limited filtration capacity, fiberglass filters need to be replaced more frequently, typically every 30 days.


Pleated Filters

Pleated filters, made from polyester or cotton paper, offer a significant upgrade in filtration efficiency compared to fiberglass filters. 

Their pleated design increases the surface area, allowing them to capture more particles and last longer.


  • Higher Filtration Efficiency: With a MERV rating ranging from 8 to 13, pleated filters can capture smaller particles, including dust mites, pollen, and mold spores.
  • Extended Lifespan: They can last from 3 months up to a year, depending on the specific model and environmental conditions.


  • Higher Cost: They are more expensive than fiberglass filters.
  • Potential Airflow Restriction: Higher MERV-rated pleated filters can restrict airflow, which might put a strain on some HVAC systems, especially older models.


Electrostatic Filters

Electrostatic filters use self-charging fibers to attract and capture airborne particles. 

Available in both disposable and washable varieties, these filters are more efficient and durable than traditional synthetic filters.


  • Effective Particle Capture: Electrostatic filters are good at capturing smaller particles, including dust, pollen, and bacteria, thanks to their self-charging fibers.
  • Reusable Options: Washable electrostatic filters can be cleaned and reused, offering long-term cost savings​.


  • Higher Initial Cost: They are more expensive initially compared to standard disposable filters.
  • Maintenance Required: Washable filters need regular cleaning to maintain their efficiency.


HEPA Filters

High-efficiency particulate Air (HEPA) filters are known for their superior filtration capabilities. 

They can capture up to 99.97% of particles as small as 0.3 microns, including dust, pollen, mold spores, and even some bacteria and viruses. 

However, HEPA filters are typically not used in standard residential HVAC systems because they can significantly restrict airflow.


  • Highest Filtration Efficiency: Ideal for environments where air quality is critical, such as hospitals and laboratories.


  • Not Suitable for Standard HVAC Systems: Due to their high resistance to airflow, they can strain standard HVAC systems.
  • High Cost: They are more expensive than other filter types.

By understanding the different types of HVAC filters and their respective advantages and disadvantages, homeowners can make informed decisions that best suit their needs and ensure optimal indoor air quality and system efficiency.


How to Choose the Right HVAC Filter

Understanding MERV Ratings

When selecting an HVAC filter, one of the most important factors to consider is the Minimum Efficiency Reporting Value (MERV) rating.

The MERV rating measures a filter’s ability to capture particles between 0.3 and 10 microns. 

The higher the MERV rating, the better the filter is at trapping small particles, but it can also restrict airflow if the rating is too high for your system.

  • MERV 1-4: Provides minimal filtration and is typically used in residential settings to protect the HVAC system rather than improve air quality.
  • MERV 5-8: These filters can capture large particles such as dust and mold spores and are commonly used in residential and commercial applications.
  • MERV 9-12: These offer better filtration for smaller particles like pet dander and fine dust, making them suitable for homes with allergy sufferers.
  • MERV 13-16: Capable of trapping even smaller particles, including bacteria and some viruses. These are often used in hospitals and environments where air quality is crucial.


Factors to Consider

Choosing the right HVAC filter involves considering various factors beyond just the MERV rating:

  • Household Needs:
      • Allergies: If you have family members with allergies or asthma, opt for a filter with a higher MERV rating (11-13) to capture more allergens.
      • Pets: Homes with pets can benefit from filters specifically designed to handle pet dander and hair. Filters with a MERV rating of 11 or higher are recommended.
      • Smokers: For households with smokers, filters with activated carbon layers are effective at reducing smoke and odors.
  • Environmental Factors:
    • Outdoor Pollution: If you live in an area with high pollution, such as near a busy road or industrial area, consider filters with higher MERV ratings (13-16) to reduce indoor contaminants.
    • Wildfire Prone Areas: In regions susceptible to wildfires, MERV 13 filters are recommended to capture fine particulate matter from smoke.


Correct Filter Sizing

Ensuring you select the correct filter size is crucial for optimal performance. A filter that doesn’t fit properly can allow unfiltered air to bypass it, reducing its effectiveness.

  • Measure Your Existing Filter: Check the size printed on the frame of your current filter. Filters are usually sized by their nominal dimensions (e.g., 20x25x1 inches), but it’s essential to confirm the actual dimensions to ensure a proper fit.
  • Standard Sizes: Common sizes include 16x25x1, 20x25x1, and 20x20x1. Make sure to match the thickness as well, since thicker filters (e.g., 4 or 5 inches) may not fit all HVAC systems.

By understanding MERV ratings and considering your household and environmental needs, you can select the best HVAC filter to ensure clean air and efficient system performance.


Replacing HVAC Filters.
Photo from iStock – Credit: lja Enger-Tsizikov

Maintenance and Replacement of HVAC Filters

How Often Should You Change Your Filter?

Regular maintenance of your HVAC filter is essential for maintaining the efficiency and longevity of your system, as well as ensuring good indoor air quality. 

The frequency of filter replacement depends on several factors, including the type of filter, your household environment, and how often you use your HVAC system.

  • Fiberglass Filters: These basic filters typically need to be replaced every 30 days due to their limited ability to capture particles and their tendency to become clogged quickly.
  • Pleated Filters: Depending on the MERV rating and environmental conditions, these filters can last between 3 months to a year. A higher MERV rating or a household with pets or allergy sufferers might require more frequent replacements.
  • Electrostatic Filters: Reusable electrostatic filters should be cleaned regularly, about every month, while disposable versions may need replacement every 3 months.
  • HEPA Filters: These are generally replaced every 6 to 12 months, but specific guidelines should be followed based on the manufacturer’s recommendations.


Signs Your Filter Needs Replacing:

Knowing when to change your HVAC filter can sometimes be as simple as looking for signs that it’s time for a replacement:

Visible Dirt and Debris: If the filter looks visibly dirty or clogged, it’s time for a change. A clean filter should allow light to pass through; if it doesn’t, it’s overdue for replacement.

Reduced Airflow: If you notice a significant drop in airflow from your vents, a clogged filter might be the cause. This can lead to higher energy bills and increased strain on your HVAC system.

Increased Allergy Symptoms: If household members are experiencing more allergy or asthma symptoms, it might be due to a dirty filter failing to capture allergens.


Best Practices for Filter Maintenance:

  1. Regular Inspections: Check your filter at least once a month. Even if it’s not time to replace it, you might notice it needs cleaning or is getting clogged faster than expected.
  2. Set Reminders: Use your phone or a calendar to set reminders for filter checks and replacements. This helps ensure you don’t forget to maintain your filters regularly.
  3. Vacuum Around Vents: Keeping the area around your HVAC vents clean can reduce the amount of dust and debris that the filter has to capture, extending its lifespan.
  4. Follow Manufacturer’s Guidelines: Always refer to the manufacturer’s instructions for specific recommendations on filter maintenance and replacement schedules.

By adhering to these practices, you can enhance the efficiency of your HVAC system, improve indoor air quality, and potentially extend the lifespan of your system’s components.


The Hidden Costs of Neglecting Your HVAC Filters

Increased Energy Bills

One of the most immediate and noticeable impacts of neglecting your HVAC filter is a rise in energy bills. 

A dirty or clogged filter restricts airflow, causing the HVAC system to work harder to maintain the desired temperature. 

This increased workload leads to higher energy consumption. According to the U.S. Department of Energy, replacing a clogged filter with a clean one can reduce an air conditioner’s energy consumption by 5% to 15%.


Shortened HVAC System Lifespan

Ignoring regular filter maintenance can significantly shorten the lifespan of your HVAC system.

When the filter is clogged, the system’s components, such as the blower fan and motor, have to work overtime to push air through the obstructed filter. 

This added strain can lead to overheating and increased wear and tear, ultimately resulting in more frequent breakdowns and the need for costly repairs or premature system replacement.


Health Implications

Neglecting your HVAC filter can also have serious health implications. 

A dirty filter fails to capture airborne pollutants effectively, allowing dust, pollen, mold spores, and other allergens to circulate throughout your home. 

This can exacerbate allergy and asthma symptoms and contribute to poor indoor air quality. In severe cases, prolonged exposure to these pollutants can lead to respiratory issues and other health problems.


Impact on Comfort and System Performance

A neglected HVAC filter can also affect the overall comfort and performance of your heating and cooling system. 

When the filter is clogged, it can cause uneven heating or cooling, creating hot and cold spots throughout your home. 

This not only makes your living environment less comfortable but can also lead to increased thermostat adjustments and further strain on your HVAC system. 

In Kingman, AZ, where temperature extremes are common, maintaining a clean filter is crucial for consistent comfort.



Maintaining your HVAC system is critical for ensuring efficient performance, healthy indoor air quality, and extended equipment lifespan. 

HVAC filters play a crucial role in this maintenance process by trapping dust, pollen, mold spores, and other airborne particles that could harm your system and your health. 

Understanding the different types of filters, their effectiveness, and the appropriate MERV ratings helps you make informed decisions that best suit your household needs.

Regularly changing your HVAC filters can lead to significant energy savings, improved system reliability, and better overall air quality. 

Neglecting filter maintenance can result in higher energy bills, frequent repairs, poor indoor air quality, and increased health risks.

If you’re in Kingman, AZ, ensure that you follow these maintenance tips to keep your HVAC system running smoothly and your indoor environment healthy.



  1. How often should I change my HVAC filter?

    The frequency of changing your HVAC filter depends on several factors, including the type of filter, your household environment, and usage. Generally, fiberglass filters should be replaced every 30 days, pleated filters every 3 to 6 months, and electrostatic filters should be cleaned monthly if they are reusable. HEPA filters may last 6 to 12 months but always follow the manufacturer’s recommendations.

  1. What is a MERV rating and why is it important?

    MERV stands for Minimum Efficiency Reporting Value and it measures the effectiveness of air filters in capturing particles. The higher the MERV rating (ranging from 1 to 16), the more efficient the filter is at trapping smaller particles. Choosing the right MERV rating is crucial because a filter that is too restrictive can impede airflow and strain you.

  1. Can a dirty HVAC filter affect my energy bills?

    Yes, a dirty HVAC filter can significantly increase your energy bills. When the filter is clogged, it restricts airflow, causing your HVAC system to work harder to maintain the desired temperature. This extra effort leads to higher energy consumption and increased utility costs. Replacing a dirty filter with a clean one can reduce your system’s energy consumption by 5% to 15%.

  1. What are the health risks of not changing my HVAC filter regularly?

    Neglecting to change your HVAC filter can lead to poor indoor air quality, which can exacerbate allergies, asthma, and other respiratory issues. A dirty filter fails to capture airborne pollutants such as dust, pollen, mold spores, and pet dander, allowing them to circulate in your home. This can lead to increased health risks and discomfort for household members​.

  1. How do I choose the right size HVAC filter?

    Choosing the right size HVAC filter is crucial for optimal performance. Filters are sized by their nominal dimensions (e.g., 20x25x1 inches) and actual dimensions. To ensure a proper fit, check the size printed on your current filter or measure it manually. Using the wrong size filter can lead to unfiltered air bypassing the filter and reducing its effectiveness​.

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