Residential Air Filters
According to the EPA, indoor air quality (IAQ) is among the top five environmental health risks. The best way to address this risk is to control or eliminate the sources of indoor air pollutants and ventilate a home with clean outdoor air. However, in some regions weather conditions or outdoor contaminants limit opportunities for proper ventilation.
Air Filter Manufacturers Use Various Acronyms to Describe Air Filter Efficiency
- MERV. MERV is an acronym for Minimum Efficiency Reporting Value. This is now an international industry standard set up by the committee that oversees the filter industry. This standard is used for determining the filters ability to capture and hold dirt and dust in specific size ranges. Some filter manufacturers use their own rating system. Which is not approved as an industry standard. Always ask for the standard MERV number.
- MPR. Per 3M, this stands for Micro-Particle Performance Rating. This is a ratings system that ranks filters on their ability to capture airborne particles smaller than 1 micron. The best residential air filters have MPRs between 1500 and 1900.
- FPR. Filter Performance Rating – this is Home Depot’s own rating system. It works on a scale of 1 to 10, with the higher the number the more efficient it’s filtration capability.
- HEPA. This acronym stands for high-efficiency particulate-arresting. HEPA filters are electrostatic, meaning that they use an electrical charge to help trap airborne particles. HEPA filters help reduce the amount of dust blown through the heating system, helping people with asthma or other chronic lung diseases.
Understanding MERV Ratings
The American Society of Heating, Refrigerating, and Air-Conditioning Engineers (ASHRAE) introduced IAQ standards as part of a change in the air-filtration industry. ASHRAE has since promoted the minimum efficiency reporting value (MERV) system to standardize definitions of air filtration efficiencies.
By placing quality air filters within a home’s ventilation system, you can block a number of irritating and harmful airborne particulates, including pollen, animal dander, mold spores, viruses and bacteria, depending on the product’s Minimum Efficiency Rating Value (MERV). For optimal performance, it’s best to choose filters with a MERV Rating between 8 and 13.Tthe higher the overall MERV rating, the better the filter’s ability to block various types of contaminants.
Types of Residential Air Filters
Several types of air filters are common in residential and commercial HVAC systems:
Fiberglass air filters.
These are common throwaway air filters that consist of layered fiberglass fibers, forming the filter media. Metal grating supports the fiberglass and prevents it from failing and collapsing. While these air filters are extremely effective for protecting your HVAC unit from large damaging particles, fiberglass air filters don’t significantly improve the air quality in your home. Fiberglass filters are one of the least expensive of air filter types, but they must be replaced more frequently. If improving indoor air quality is a priority for your home, especially if anyone in your family suffers from allergies, we recommend avoiding these types of filters. Fiberglass air filters are rated between 1 and 4 on the MERV scale.
Polyester and pleated air filters.
These filters are similar to fiberglass filters, but they typically have a higher resistance to airflow as well as superior dust-trapping capabilities as compared to fiberglass air filters. These filters remove about 45% of air pollutants in your home. Pleated air filters have the added advantage of capturing more airborne particles without significantly restricting the airflow of your HVAC system. Polyester and pleated air filters have a MERV rating of 8 to 13 and they cost around $10. These are an ideal solution for homeowners concerned about indoor air quality.
High-efficiency particulate-arresting (HEPA) filters.
These units filter the air passing through them at an incredibly fine scale. These are the most effective at removing pollutants from indoor air, but they are also the most expensive. Made from pleated filter paper or synthetic polyester fibers, high-efficiency filters remove 85 percent of airborne particles, including dust pollen, and mold. High-efficiency filters have a MERV rating between 14 and 16, but are not the best for home HVAC units. These filters are typical for industrial settings such as hospitals and other sterile environments. The U.S. Department of Energy (DOE) and its contractors use HEPA filters that meet DOE standard STD-3020-97. Specification for HEPA Filters Used by DOE Contractors, to filter 99.97 percent of all particles 0.3 microns or larger.
Washable air filters.
Washable air filters are not recommended for most residential HVAC systems. These filters usually run about $20 and require additional maintenance. They rely on the build-up of dust along the cloth to improve the efficiency of the filter. Washable air filters are also more susceptible to collecting fungus, bacteria, and other microorganisms that can escape from the filter and circulate throughout your home. The MERV rating for washable filters is usually between 1 and 4.
Connect with Sierra Filtration
At Sierra Filtration, we have a comprehensive array of residential air filters and air filtration products. Regardless of your residential A/C or heating system, our air filters help promote better indoor living conditions and superior air quality, all while increasing the efficiency and longevity of your HVAC system. Connect with us today!