With the exception of permanent filter furnaces, you need to regularly replace the filter. Michael Rubino, a mold and air quality expert and founder of the non-profit organization HomeCleanse, points out that factors such as the home’s location, the age of the HVAC system, and the state of the air quality can influence how often air filters need to be replaced. “A few signs to look out for,” Michael says, “include discoloration of the filter, odd odors, higher electricity bills, a decrease in airflow, or dust around the vents or condenser coils. Chronic health issues can also point to poor indoor air quality.” We researched the top furnace filters on the market, evaluating filter type, MERV rating, filter life, and overall value. Our top recommendation is the Filtrete Dust, Pollen & Pet Dander Air Filter. This disposable filter is easy to install and efficient, and it traps many of the most common air contaminants. Here are the best furnace filters. The product balances performance and affordability, making it a good choice for most households. Its electrostatically charged filter attracts and holds particles to the filter media, increasing the effectiveness. This filter has a MERV 8 rating, meaning it is also designed to capture mold spores, dust mite debris, and lint. However, it isn’t equipped to capture very fine particles or aerosols such as smoke, droplets from a sneeze or cough, or viruses and bacteria. Still, it meets more than the bare minimum of filtration requirements and should reduce the airborne particulates that are most likely to cause visible dust or trigger common allergies. For maximum effectiveness, you should change the filter every 90 days, or sooner if you see evidence of heavy debris collection. Price at time of publish: $56 The Filtrete Basic Dust Air Filter is an economical choice that uses electrostatically charged filter media to capture lint, dust mite debris, and household dust. It has an MPR rating of 300, which is considered a sufficient base level when shopping for residential air filters. Changing the filter every 90 days can reduce the amount of dust and small debris circulating through your home’s HVAC system. However, this filter may not be effective enough if you’re specifically targeting mold spores, or allergens such as pet dander and pollen. Another reason to consider this affordable furnace filter is its reduced resistance and strain on your HVAC system. Some filters with a higher MERV rating have thicker, move tightly woven filter material to trap fine particles. While that does increase the filter’s effectiveness, it also can make the HVAC system work harder as it takes air in. If you have an older HVAC system or minimal air filtration needs, or just want to save a few dollars every time you replace your air filter, then the Filtrete Basic Dust Air Filter is the way to go. Price at time of publish: $46 We like that this air filter for homes with pets uses the neutral properties of baking soda to offset odors without adding an artificial or chemical scent to the air. It has a MERV rating of 8, and the manufacturer claims that it removes up to 75 percent of large particles from the air circulating in your home’s HVAC system. The filter material’s pleats are designed to capture pet dander, pollen, and mold spores so they are not blown through your air ducts. We note that the filter frame can be somewhat subject to crushing or tearing, so insert it gently into your air handler. Price at time of publish: $35 This option has been certified as asthma and allergy-friendly by the Asthma and Allergy Foundation of America (AAFA). To earn the certification, products must be proven to capture common household triggers, like cat allergen, dust mite allergen, pollen, and general small particles. The Filtrete Advanced Allergen Reduction Air Filter also has a 3M proprietary 1500 MPR rating, which the manufacturer says compares to MERV 12. This is well above the MERV 9 threshold that is commonly recommended for air filters to trap allergens. Depending on your home’s air quality, you may find it necessary to change the filter more often than the Filtrete-recommended 90-day replacement schedule. The manufacturer doesn’t include a sensor to monitor air flow and alert you when performance drops significantly. So you need to inspect the filter periodically to keep tabs on when it’s ready to be replaced. Price at time of publish: $105 for 4 pack With a MERV 11 rating, this air filter is effective at capturing contaminants such as smoke, environmental pollution, and pet dander. These particles can contribute to a stale or unpleasant odor in your home, but the electrostatic filter material holds on to the particles, while the activated carbon reduces the odor they emit. In combination, this air filter for odors reduces particles in your air supply while contributing towards a more neutral smell. Each filter lasts up to 90 days. The price per filter is slightly higher, given the filtration limitations (it doesn’t capture viruses or bacteria). But we consider it an efficient choice if you want to filter and deodorize your home’s air supply. Price at time of publish: $36 for 2 pack To keep you on track with your filter replacement schedule, we recommend the Filtrete Smart Air Filter. This MERV 12 furnace filter traps contaminants such as pollen, dander, smoke, viruses, and bacteria. A small integrated sensor monitors air flow efficiency and gives you up-to-date information on air filter status. You also can enable auto-reorder through the app, which ensures that you have a new filter ready to when your current filter expires. The Filtrete Smart app also offers air-quality information, but these are just generalized air quality reports based on your area. While detailed information about the air inside your home might be nice, the biggest benefit of the app is the ability to check your filter’s life status at a glance using your smartphone. We believe this is much more convenient than remembering to regularly open your HVAC unit to visually inspect the filter. Price at time of publish: $24 The AIRx Air Beast is our recommendation if you’re looking for a filter to trap many of the most common contaminants without straining most HVAC units, which can lead to the need to replace the furnace. It has MERV 11 filtration and a rated velocity of 295 feet per minute (FPM), which is within range of the maximum recommended 300 FPM for air filters. The AIRx Air Beast has pleated synthetic filter media. This translates into more surface area to collect particles such as dust, smoke, mold, and dander when compared with furnace filters with flat filter surfaces. This filter is also electrostatically charged, which assists in drawing these contaminants into the filter and trapping them there. As most other disposable filters, this product lasts up to 90 days but should be replaced sooner if it becomes very dirty. If you fail to replace the filter on time, air flow is restricted, and you risk damage to your HVAC system. Price at time of publish: $65 for pack of 4
You may notice that this furnace filter is significantly thicker than 90-day furnace filters. The extra depth is filled with pleated filter media to maximize the surface area available for capturing contaminants. This is an electrostatic filter, so the charge helps to draw in particles such as dust mites, mold, and smoke. Because of this furnace filter’s four-inch depth, you need to make sure it fits into your HVAC’s filter opening. Price at time of publish: $79 When shopping for a furnace filter for dust, choose one with a MERV rating of 5 to 8. Filters in this range are designed to capture 80 to 90 percent of particles from three to 10 microns in size, which includes most dust particles. The FilterBuy Dust Defense carries a MERV 8 rating and further enhances its ability to capture dust and other particles by using electrostatically charged filter media. It lasts for up to 90 days before needing replacement and is an affordable option for a disposable furnace filter. However, it’s not as effective at filtering out smaller particles such as smoke and viruses or bacteria. Price at time of publish: $24 The filter’s electrostatic charge is responsible for its particle capture capabilities, and it contains an EPA registered antimicrobial material to protect against mold and mildew growth. Because it doesn’t capture particles measuring 2.5 microns or less, such as smoke, viruses, and bacteria, it might not fit the needs of every household. Price at time of publish: $50 Our top recommendation for a furnace filter is the Filtrete Dust, Pollen, & Pet Dander Air Filter. With a MERV 8 rating, it’s a popular pick for general household use and reduces large particles in the air along with visible dust on flat surfaces. One very economical option is the Filtrete Clean Living Basic Dust Air Filter. This filter has a MERV 5 rating, and is effective at keeping large particles from clogging your HVAC unit, as long as you regularly replace it at least every 90 days. The most common furnace filter thickness is one inch. However some air handler boots are designed for four- and five-inch filter options, which usually offer a longer useful life span and may put less strain on the HVAC system, ensuring good ventilation.
Filtration Level
The filtration level of a furnace filter is largely determined by how tightly woven the filter material is and what-size particles it can trap. A more tightly woven filter material translates into a higher capture rate of smaller-size particles. There are various ways of classifying the filtration level of a furnace filter, including MERV, MPR, and FPR. MERV (Minimum Efficiency Rating Value), is a national standard, set by the American Society of Heating, Refrigerating, and Air Conditioning Engineers (ASHRAE). It classifies which particles a filter can capture. A MERV rating of 8 means the filter is designed to capture pollen, dust, and mold. A rating of 11 adds large dust particles and auto emissions. A filter rated MERV 13 may be capable of trapping particles emitting from sneezes, as well as all bacteria. You should choose a filter with a MERV rating that matches your objectives. If you’re only concerned with preventing dirty ducts and keeping your HVAC system clog-free, then a filter with a MERV rating of 1 to 4 is sufficient. However, it’s not as likely to improve your air quality. For that, choose a MERV 5 to 8 filter, which can remove some of the most frequent airborne allergens and reduce household dust. For more acute allergies or to ensure a higher standard of air quality, use a filter with a rating of MERV 9 or above. A higher MERV rating means the filter material is more tightly woven, requiring the HVAC system to work harder to draw air through the filter. This can restrict air flow, so it is important to check the filter specifications of your HVAC system or get advice from a technician. The 3M Company and The Home Depot have created similar systems. The 3M Microparticle Performance Rating (MPR) system, for products it sells under the Filtrete and other brands, runs from 100 (lint and household dust) all the way to 2800. Filters rated that high are designed to trap viruses, the manufacturer says. Home Depot applies its Filter Performance (FPR) Rating to products it sells. Ratings run from 4 (dust, pet dander) to 10 (bacteria, mold spores, odors, and more).
Media
A furnace filter’s media can be made from different materials. Filters made of fiberglass are among the cheapest and most basic options, but they are quickly being replaced by filters with synthetic media because of their affordability and improved filter life. Furnace filters may also utilize a cotton filter material, which offers a tight weave to capture particles. Permanent furnace filters are usually made from long-lasting polypropylene and only require rinsing every few months to maintain performance. A galvanized metal frame around the filter makes them easy to install. Disposable furnace filters usually have cardboard frames that can sometimes become crushed, torn, or bent during installation. One other thing to note is whether the filter material has an electrostatic charge. It uses this charge to attract particles floating in the air and draw them into the filter media. The charge also helps ensure that the particles aren’t passed through to the HVAC system as easily.
Why Trust The Spruce?
Erica Puisis researches the best home improvement and lifestyle products that make life easier and better. Her areas of expertise include home appliances and systems. For this roundup of the best disposable, washable, and permanent furnace filters, Erica considered the most popular products from leading brands such as 3M-produced Filtrete, as well as FilterBuy, AIRx, and Honeywell Home. All filters in this roundup have at least a MERV 5 rating.
As Michael Rubino, a mold and air-quality expert and founder of the non-profit organization HomeCleanse explains: “All filters are designed differently and have varying capacities for eliminating pollutants from the air. The most common way to determine the effectiveness of a filter is by using a grading system called MERV. The more effective the filters are at eliminating contaminants from the air, the higher the rating will be. For example, some are only equipped to deal with large particles like dust, while others can eliminate bacteria and allergens.”
Permanent furnace filters can last years when regularly cleaned. You need to regularly remove the filter, rinse it with water, and allow it to dry before replacing it.
If you’re looking for HEPA air filtration, Michael advises considering a whole- home air purifier. “These systems are installed at the home’s point of entry and will effectively remove contaminants from the air so that the HVAC system can run efficiently," Rubino says. Erica also interviewed Michael Rubino, a mold and air-quality expert, author of The Mold Medic, and founder of HomeCleanse, a non-profit with a mission to improve poor air quality and toxic indoor environments. He explained the difference between air-quality standards and the importance of choosing an air filter that meets your health needs and HVAC system requirements.
