Air filters transform the HVAC system, furnace, or air conditioning system into an air cleaner for fresh, healthy air, free of pollutants and allergens. When top air filters trap dust, pet dander, mold, pollen, and small particles, it prevents the system from clogging, ensuring optimal operating efficiency. The best furnace filters capture particles improving the indoor air quality.
We researched for days creating a shortlist of the best furnace filters from the vast selection of types, sizes, thicknesses, and MERV ratings. We’ve selected the top furnace filters for allergies, pet owners, odor-resistant, and household dust, mites, and other fine particles that cause allergies.
If the different ratings also confuse you, then read on. We explain MERV ratings and compare furnace filters with FPR or MRV ratings with the MERV rating.
Here’s The Top HVAC and Furnace Filters We Would Buy in 2021
What Is The Best MERV Rating For Furnace Filters?
MERV (Minimum Efficiency Reporting Value) measures how well a filter removes airborne particles and debris from the air. MERV ratings range from 1 to 20, and the higher the number, the smaller the particles, like smoke and pollen, the filter traps. MERV measures particles from 0.3, the smallest to 10 microns, the largest and easiest to filter. MERV 8-13 filter ratings (medium-efficiency) remove about 90 percent of the airborne particles and are the most commonly used in homes.
MERV Rating Categories
- MERV 1 to MERV 4 filters are the most basic MERV-rated filters and often the cheapest. These filters improve the running efficiency and prolong equipment life by catching particles larger than 10 microns in size. Carpet fibers, pet hair, and heavy dust can clog the heating-cooling coils and ducts in the HVAC system.
- MERV 5 to MERV 7 filters traps midsize particles, like mold spores and pollen that causes mold growth on the coils, ranging in size from 3 to 10 microns.
- MERV 8 to MERV 13 filters are the most commonly used for indoor air quality. The higher-end filters in this group can remove more than 50 percent of 0,3 to 1-micron particulates. These filters also capture the larger particles with lower MERV numbers and smaller particles 0.3 to 3 microns in diameter like bacteria, smoke, and exhaust particles to ease respiratory ailments and reduce indoor fine-particulate pollution.
Pollutant And Common Type Of Allergen Sizes
The chart indicates micron sizes of particles to help you decide the best furnace filter you need.
- 0.1-.0.2 microns – smoke
- 0.2-0.3 microns – bacteria
- 0.5-10 microns – pet dander, household dust, dust mite debris
- 10-30 microns – mold spores
- 15-200 microns – pollen
- 60-80 microns – human hair, pet fur
- 100+ microns – dust mites
- Pressure Drop And MERV Furnace Filters
It may seem obvious to buy the highest rating MERV furnace filter, but it depends on the standard sizes for the equipment. The higher MERV filter will block airflow more than the lower MERV filters causing back-pressure in the HVAC system; the more significant drop in air pressure could decrease system efficiency.
In a worst-case scenario, you can damage your furnace if the pressure drops too much. Ensure you know how much pressure drop the HVAC system has and how much it can handle, or you could shorten its life by purchasing the wrong air filters.
Types Of Filters
HEPA (High-Efficiency Particulate Air) filters are excellent all-around furnaces filters for a heating unit and the best furnace filters for people with allergens, household dust particles, and dust mite debris sensitivities. HEPA filters catch 95 percent airborne particles 0.1 microns in size and 99.97% of all airborne particles 0.3 microns and larger.
HEPA Filters catch dust, mite debris, pollen, mold, bacteria, viruses, and pet dander but not gases, smoke, chemicals, and odors; you need an activated carbon filter for that, which works with the furnace filter. Although trapped, the microorganisms can still breed and reproduce.
Activated Carbon Filters
The active carbon filter is used with an additional filter, like the HEPA filter, to trap a more comprehensive selection of pollutants and prevent pollutants from becoming airborne. Activated carbon filters have absorbent pores that chemically react to pollutants—the carbon bonds with smoke, chemicals, gasses, odors, dirt, and debris. Although an older type of filter, these filters are excellent if odors are an issue.
The two types of pleated filters are high-efficiency pleated filters and disposable pleated filters.
Disposable Pleated Air Filter
Pleated disposable filters are for those who aren’t allergen sensitive but want to improve the indoor air quality. Replace disposable filters every 30 days. To avoid the heating unit working overtime or restricted airflow, ensure you change the filters always at the same time of the month. These filters are inexpensive, readily available, and generally, work better than disposable fiberglass filters.
High-Efficiency Pleated Air Filter
The high-efficiency pleated filter is an ideal type of furnace filter to help prevent the spreading of diseases. These filters function efficiently in large workspaces, homes for large families, and people with upper respiratory issues. The thicker design doesn’t fit in all furnaces, and the high efficiency makes it a more expensive option.
Disposable Fiberglass Filters
Disposable fiberglass filters capture larger-sized particles and also require replacement every 30 days like the disposable pleated filters. Make sure you change the filters according to schedule because they clog quickly, resulting in the cooling system or heating system working harder and more energy usage.
Electrostatic filters are constructed with cotton fibers or self-charging paper that produces a positive charge that attracts smaller particles. These filters are excellent for homes with pets, people with allergies, smokers, and young kids. The filters can be costly, but the washable filters have a longer lifespan than permanent filters.
How To Determine Air Filter Size, Thickness, And MERV
When purchasing a new furnace filter, there are certain things to consider. These features will help you select the best furnace filter and the correct filter for your furnace, air conditioner, or heating system.
Air Filters Thickness
The filter thickness determines the filter’s ability to remove particles and its efficiency. One inch is the standard thickness; some brands also have thicknesses varying from 2-inch to 6-inches. Make sure the heating system can accommodate a thicker furnace filter before purchasing it.
Air Filters Sizes
Filters have two measurements, the actual size, and the nominal size. For example, a 20 x 20 x 1-inch furnace filter’s actual size is usually 19.75 x 10.75 x .75 inches. Make sure you buy the correct filter size for the heating unit; the filter will stay in place and be easier to slide in. You will find the correct filter size printed on the existing furnace filter or use a standard measuring tape to measure the current furnace filter’s length, width, and thickness.
MERV, MPR, And FPR Ratings Compared
The ASHRAE (American Society of Heating, Refrigerating, and Air Conditioning Engineers) created the MERV rating (Minimum Efficiency Reporting Value) to help improve interior air quality. However, not all brands use the MERV rating; 3M Filtrete and Honeywell use a different performance rating. 3M Filtrete uses MPR (Microparticle Performance Rating), and Honeywell uses FPR (Filter Performance Rating). Here is how the most common filter ratings compare:
- MERV 8 compares to FPR 5 and MPR 600
- MERV 10 compares to FPR 6 and MPR 1000
- MERV 11 compares to FPR 7 and MPR 1200
- MERV 12 compares to FPR 8 or 9 and MPR 1500
- MERV 13 compares to FPR 10 and MPR 1900
- MERV 14 compares to MPR 2800
Best Furnace Filters For HVAC Systems, Furnace, And Air Conditioning Units
We’ve listed below our choices for the best filters for your furnace this year. Because there are literally hundreds of different sizes of filters to fit all the different size furnaces in existence, we’ve decided to provide you with a link to a page where you can choose the size that fits your own needs.
Don’t be overwhelmed – as long as you know what the dimensions are on the filter you currently have in your HVAC system, it’s easy to choose the right replacement.
Best Furnace Filters For Pet Owners: Filterbuy Air Filter Pleated HVAC AC Furnace Filters MERV 8
The Filterbuy Pleated Air Filter is the best HVAC, AC, furnace air filter for circulating clean air in homes with pets. It’s what I use in my house to keep our dog dander down.
The quality furnace filter helps protect against 90 percent of airborne particles, including dust mites particles, lint, mold, pet dander, and pollen, without impacting airflow.
Made from recyclable materials, the eco-friendly electrostatically charged design features12 pleats per foot offers a larger surface area to capture more particles and prolongs the filter’s lifespan. The air filter’s frame supports heat up to 200 F, and the industrial-grade beverage board frame with a dual wire backing for structural integrity withstands exposure to moisture.
Arrows on the frame show the direction of airflow for easy installation in the correct direction. The 20 x 20 x 1inches furnace filter’s actual size is 19.5 x 19.5 x 0.75 inches.
Rating: MERV 8, FPR 5, MPR 6000
Replacement Time: 3 months
Thickness Range: 1-inch, 2-inch, 4-inch
Compatible Devices: HVAC system, air conditioner, air cleaner, furnace
Package: 2 pack, 4 pack
Sizes: Wide range of sizes in MERV rating 8, 11, and 13
Best Furnace Filters For Household Dust: Aerostar Pleated Air Filter, AC Furnace Air Filter MERV 11
The Aerostar Pleated Air Filter is another excellent furnace filter for those worried about dust and dander. It was a close runner up for being recommended for pet owners – we . Designed to trap cough-sneeze debris, household dust, lint, dust mites, mold, smog, smoke, pet dander, and pollen, the filter medium is suitable as furnace filters, air conditioner filters, and HVAC systems.
Electrostatic technology charges the synthetic material attracting and trapping common particles and airborne contaminants 0.3-1 micron in size that causes allergies. The zig-zag pleated pattern fits in a solid criss-cross metal frame and is made for high efficiency and low airflow resistance.
The manufacturer recommends changing the current filter every two to three months and every 30 days during peak summer and winter. Made in the USA, these affordable filters will keep your indoor airflow clean and healthy. Some reviewers mentioned that the actual size is about 0.25 inches shorter than expected.
Rating: MERV 11, FPR 7, MPR 1000-1200
Replacement Time: 2-3 months, 30 days peak months
Thickness Range: 1-inch
Compatible Devices: Furnace, air conditioner unit
Package: 6 pack
Sizes: Wide range of sizes in MERV rating 8, 11, and 13
Best Furnace Filters With Smart App: Filtrete Smart Replenishable AC Furnace Air Filter MERV 12
The Smart Replenishable AC Furnace Air Filter is a Bluetooth-enabled HVAC filter that tracks the filter life based on usage and airflow. These are the best furnace filters for homeowners who forget to replace their furnace filters; the smart app reminds you. The Bluetooth-enabled sensors track air filter life, and when it’s time for a replacement, you will get a reminder.
A proprietary 3M algorithm determines the filter life of Filtrete Smart Air filters. The Smart App recognizes the air pressure changes and calculates the particle capture efficiency for optimal airflow for your system. With the Dash Replacement enabled, the Smart App automatically orders replacement filters when it is time for replacing the furnace filters. Homeowners save 15% when signing up for the Amazon Dash Replacement feature.
With a MERV rating of 12, Filtrete’s 3-in-1 technology, the furnace filters attract a wide range of airborne pollutants, including mold spores, dust, soot, lint, pollen, and pet dander. It also traps bacteria, viruses, dust mite debris, cough, sneeze debris, smoke, and other microscopic particles creating a healthier and fresher airflow. Certified asthma and allergy-friendly furnace filters are excellent to improve indoor air quality for people with allergies.
When outside, the Filtrete Smart App can display the outdoor air quality for multiple locations. The app gives tips on how to help improve your home’s air quality and keeps track of the type and size filter for easy reordering. Download the Filtrete Smart App, pair it with the Smart Air Filter, and receive notifications on iOS and Android devices.
The furnace filters come in various sizes. The actual size of the 20 x 20 x 1 air filter is 19.719 x 19.719 x 0.78 inches.
Rating: MERV 12, MPR 1500
Replacement Time: Smart App reminds or automatically reorders
Thickness Range: 1-inch
Compatible Devices: Furnace, HVAC system
Package: 2 pack, 6 pack
Sizes: Wide range of sizes in MERV rating 12 and 13
Best Furnace Filters For Allergies: Nordic Pure AC Furnace Air Filters MERV 13
Having trouble with seasonal sniffing and tearing? The Nordic Pure Honeywell Furnace Filters are great furnace filters for knocking down hay fever and other annoyances. The electrostatic furnace filter is thicker than the standard size and captures more airborne particles and microscopic allergens, perfect for cleaner air and people suffering from allergies. With its high MERV rating, the finer filter removes more air pollutants and harmful particles, doing a better job at air filtration than furnace filters with lower MERV ratings.
Environmental-friendly, the air filter frames are constructed from heavy-duty moisture-resistant beverage board paper. The material is electrostatically charged, drawing unwanted particles and airborne allergens that cause allergy symptoms. The pleated thicker filters protect you from fine dust, cooking smoke, bacteria, airborne plant spores, tobacco smoke particles, pollen, and pet dander. The non-woven synthetic filter media deters any growth of mold spores or bacterial on the air filters.
The manufacturer recommends the regular replacement of dirty filters and suggests changing filters more frequently for pet allergies and other allergies caused by airborne contaminants. Homeowners should replace 5-inch furnace filters every 3-6 months. Made in the USA, the company also manufactures Pleated Plus Carbon air filters for cleaning the air from lingering odors caused by cooking, laundry, heat, and pets.
Rating: MERV 13, FPR 10, MPR 2200-2400
Thickness Range: 0,5-inch, 1-inch 2-inch, 4,-inch, 5-inch, and 6-inch
Replacement Time: 1-6 months based on the filter thickness
Compatible Devices: Furnace, HVAC system
Package: 2 pack, 4 pack, 6 pack
Sizes And MERV Ratings: Wide range of sizes in MERV rating from 8 to 15; Carbon Air Filters