Best Air Filters for Your Furnace and Central AC
Protect your HVAC system and clean the air in your home with one of these filters from CR’s tests
Hidden away in your basement or attic, the air filter in your HVAC system is something you probably don’t think about much. But a good air filter keeps your furnace and central air conditioner humming along by protecting the mechanicals from dust and debris. And the best filters trap indoor pollutants such as dust, pet dander, and pollen, helping to clean the air in your home.
That’s important because the concentration of air pollutants inside your home can be two to five times higher than concentrations typically found outdoors, according to the Environmental Protection Agency.
Below are the top air filters from CR’s tests (grouped by their thickness and listed in alphabetical order). We gauge how well an air filter removes dust, pollen, and smoke from the air, and see how freely air flows through the filter at any fan speed. We also calculate the annual costs of replacement filters, based on the manufacturer's recommendation for when to change them (keep in mind: prices may vary by retailer; also, it may be cheaper if you buy filters in bulk).
“Thicker filters perform better in our tests and we found that you don’t have to replace them as often,” says Dave Trezza, who oversees CR’s air filter tests. But not every HVAC system can accommodate a thicker filter—the most common size is 1 inch thick—though you can retrofit the ductwork of some systems to accept thicker filters.
Something else to keep in mind as you shop is the filtering grade given by the manufacturer. The most commonly used system applies a MERV number (minimum efficiency reporting value) to each filter, which was developed by ASHRAE (formerly the American Society of Heating, Refrigerating and Air-Conditioning Engineers). But 3M and Home Depot have each developed their own classification systems called MPR (microparticle performance rating) and FPR (filter performance rating) respectively. "No matter the grading system, the higher the number, the better the filter is at getting rid of air pollutants," says Trezza.
For more information on air filters, including some models to avoid, see our full air filter ratings and air filter buying guide.
CR’s take: The Filtrete 1900 Maximum Allergen Reduction filter is impressive at removing dust, pollen, and smoke from the air when the HVAC system is running on its highest fan speed, earning an Excellent rating in that test. But at the lowest speed, the filter is only average at removing those same airborne particles. Airflow through the filter remains strong in both instances. Filtrete recommends that you replace this filter four times a year, so, though the price is only $20 per filter, the annual cost is $80.
CR’s take: The Filtrete Ultra Allergen Reduction 1500 MPR filter earns a Very Good rating for removing smoke, dust, and pollen from the air with the system running on a high fan speed, but is only average when running on its lowest speed. In both cases, air flow through the filter is strong. Filtrete recommends changing this filter four times a year for an annual cost of $68.
CR’s take: The 4-inch-thick Aprilaire Healthy Home 213 MERV 13 earns an Excellent rating for removing dust, smoke, and pollen when the HVAC system is running on its highest fan speed. It does almost as well when running on its lowest fan speed, and air flows freely through the filter. Annual cost is $41 per year based on Aprilaire's recommendation to replace the filter once.
We also test the 4-inch Aprilaire Allergy & Asthma 216 filter, which earns similar scores. But you’ll pay $184 in annual costs because the filter costs more and Aprilaire recommends replacing it twice a year.
CR’s take: The 5-inch-thick Carrier EZ Flex Filter Cabinet with a filtering rating of MERV10 earns a Very Good rating for removing dust, pollen, and smoke from the air when a system is running on its highest fan speed, but it earns only a so-so rating of Good with the HVAC running on the lowest speed. It has no problem maintaining air flow in either scenario. Carrier recommends replacing this filter twice a year, which translates to an annual cost of $128.
CR’s take: Another good performer, the 4-inch-thick Filtrete Healthy Living Ultra Allergen 4 MPR1550 capably removes dust, pollen, and smoke with the HVAC system running on both its highest and lowest fan speeds, earning Very Good ratings. This filter provides nearly unrestricted airflow. Filtrete recommends that you replace this filter once a year, and at $29 per filter, that makes it one of the more economical filters in our tests.
CR’s take: The 5-inch-thick Lennox Healthy Climate CarbonClean 16 effectively filters dust, smoke, and pollen when the system is operating at both its highest and lowest fan speeds, with little noticeable restriction of airflow through the forced-air system. The list price for this filter is $100, although we’ve seen it selling for less. Lennox recommends that you replace it once a year.