What Are the Different Types of Air Conditioning Filters for Your Home?

What is a MERV Rating?

Air filters play a crucial role in maintaining indoor air quality by trapping various particles like dust, allergens, and microorganisms as air circulates through a building’s HVAC system. The effectiveness of these filters is measured by their MERV rating, which stands for Minimum Efficiency Reporting Value. Essentially, the MERV rating indicates how efficiently a filter can capture particles, with ratings ranging from 1 to 16. Filters with higher MERV ratings are more adept at trapping smaller particles, thus contributing to better indoor air quality.

While it may seem logical to opt for filters with the highest MERV ratings for optimal air purification, this decision isn’t always the most practical. Filters with higher MERV ratings tend to be more expensive, and their finer filtration can create increased airflow resistance. This resistance can strain the HVAC system, reducing its efficiency over time. Moreover, if the HVAC system isn’t designed to handle the increased airflow resistance, it can lead to decreased indoor air quality and put stress on the system’s fan.For homeowners looking to upgrade their air filters, it’s important to strike a balance between filtration efficiency and system compatibility. While upgrading from the default MERV 8 filter to a MERV 13 filter can significantly enhance indoor air quality by removing viruses and other contaminants, it’s essential to consult with an HVAC professional beforehand. They can assess whether your HVAC system is equipped to handle the increased airflow resistance of a higher-rated filter, ensuring optimal performance and longevity of the system.

7 Main Air Filter Types:

The primary difference between air filter types is their ability to filter various air-borne pollutants present in your home. This ability depends on the type and layout of the materials used. For example, tightly woven, layered material will filter better than thinner material.

So, to choose the most suitable HVAC filter type for your home, you need to understand how well each type of filter material performs. 

There are seven basic types of AC filters, and each comes with its perks and cons. Here is a list of all the kinds with their respective MERV rating:

1. Spun Glass or Fiberglass Air Filters

Flat-paneled fiberglass air filters also recognized as spun glass filters, are widely used in HVAC systems owing to their affordability. Comprising glass strands spun together and supported by a metal grid, these filters primarily contain fiberglass fibers. Despite their popularity due to cost-effectiveness, their ability to enhance indoor air quality is limited. Fiberglass filters can only capture approximately 20% of particles sized between 3.0 and 10.0 microns, primarily encompassing larger particles like dust, pollen, and carpet fibers. While suitable for basic debris filtration such as lint or dust, these filters lack efficacy in air purification and are prone to clogging, necessitating regular maintenance and replacement.

2. Pleated Filters

Pleated air filters are constructed with a fabric medium, commonly polyester or cotton, arranged into folds to maximize surface area for filtration. This design feature enhances their efficiency in capturing contaminants, making them more effective compared to fiberglass filters. While they come at a slightly higher price point, pleated filters offer superior performance by effectively trapping smaller air pollutants such as pollen, pet dander, and mold spores. They are available in both reusable and disposable options, providing flexibility to consumers. The pleats not only boost filtration efficiency but also contribute to prolonged durability, with some models being recyclable. However, it’s important to note that the increased performance and longevity of pleated filters may be accompanied by higher upfront costs and the potential for airflow restriction in models with numerous pleats.

3. HEPA Filters

HEPA filters are among the most efficient for HVAC systems, eliminating up to 99.97% of pollutants including dust, mold, pollen, pet dander, viruses, smoke particles, and bacteria. Ideal for those with allergies or respiratory issues, HEPA filters provide unparalleled air purification. Despite their higher cost compared to other filters, they offer long-term cost-effectiveness and only require replacement every few years. However, they may allow smaller particles like smoke or gases to pass through and can restrict airflow, potentially affecting HVAC system efficiency.

4. UV Light Filters

UV air filters use ultraviolet lights to eliminate bacteria and viruses, making them effective against harmful microorganisms. While less efficient in screening dust and other pollutants, they excel at combating pathogens like mold spores. However, they may convert oxygen molecules into ozone, posing health concerns, and are ineffective against common pollutants like dust and smoke. Despite these drawbacks, UV filters are a valuable addition to comprehensive filtration systems. Consulting an HVAC professional like Rescue Heat & Air can help determine the best filter for your home.

5. Electrostatic Filters

Electrostatic air filters utilize an electrostatic charge to attract and trap dust and airborne particles, preventing them from circulating in your home. Some of these filters are washable, offering reusable options that can cut down on costs. By employing a mixture of cotton and paper fibers to create static electricity, these filters effectively capture pollutants, making them ideal for allergy sufferers. Additionally, many electrostatic filters include a carbon filter for enhanced efficiency. Available in both flat-paneled and pleated designs, these filters cater to various preferences. Despite their affordability and effectiveness against smaller particles, electrostatic filters may not capture larger particles like mold spores or dust, presenting a potential drawback for some users.

6. Washable Filters

Washable air filters, though initially pricier than disposables, offer long-term savings and environmental benefits. Their reusable nature eliminates the need for frequent replacements, reducing waste. However, regular maintenance is essential for optimal effectiveness. While washable filters excel at capturing dust and similar contaminants, they may not address odors. Nonetheless, their affordability and eco-friendly attributes make them a practical choice for improving indoor air quality.

7. Media Filters

Media air filters offer superior filtration to standard high-MERV filters without the drawbacks of airflow or static pressure. Utilizing a paper-like material folded into pleats, these filters provide extensive surface area, making them seven times more effective than standard filters. With a lifespan of up to 2 years, they require minimal maintenance, typically needing replacement only once or twice annually. Recommended for industrial zones or individuals with weakened immune systems, media filters effectively trap pollutants. However, their installation requires professional expertise, and they do not filter out odors.

Not sure what type of filter is best for your HVAC system and your family? If you are concerned about the air quality of your home, we can help. We have several whole-home air purifiers, ventilation systems, and expert knowledge that can transform your home into a clean, healthy place to live. Get a free quote today by visiting Bowman Heating and Cooling!