The 10 Best AC Filters

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This wiki has been updated 29 times since it was first published in October of 2015. One of the easiest ways to save money on your energy bills and prolong the life of your furnace or AC unit is to keep them clean and free-flowing with regular filter changes. Made mostly of polyester, cotton, and metal media, our list includes options from the inexpensive to the hypoallergenic that are capable of trapping pollen, dust, pet dander, and even bacteria and viruses. When users buy our independently chosen editorial recommendations, we may earn commissions to help fund the Wiki.

1. 3M Filtrete Elite Allergen

2. Nordic Pure Pleated

3. 3M Filtrete Odor Reduction

Editor's Notes

January 30, 2021:

After fit, one of the most important factors when considering which filter to buy for your home is the MERV rating. Essentially, the MERV rating tells you how small of particles a particular filter can catch, with the higher the number, the smaller the contaminants it catches. Another thing to be aware of though, is that the higher the MERV rating, the more a filter will restrict airflow. For most home AC systems, something between 8 and 13 will be ideal, which is mostly what we have included here. The 3M Filtrete Ultrafine and Lennox X6675 are the two exceptions, with the the former rated at 14, and the latter at 16. These are only suitable for high-airflow systems that can handle the restriction they inevitably cause. On the opposite end of the spectrum, we have options like the NaturalAire Eliminator and Crisp MPR 600, both of which have a very low 8 MERV rating. These are a smart choice for those with older AC units that could potentially breakdown if their airflow is hindered, and for people who don't have any specific sensitivities that require them to filter out bacteria, smoke, and other microscopic particulate.

January 07, 2020:

Having to remember to change out an air filter every two to three months can be frustrating and expensive over time, but the benefits of doing so far outweigh the costs. This is especially true if you have allergies or immune sensitivities, or seniors or young children are living in your home. Dust, pollen, dirt, and other hazards are typically caught in a clean and well-functioning filter, sparing your loved ones from coughing, sneezing, headaches, dizziness, fatigue, sore throat, and other symptoms. This is true even of the smaller window and wall AC units you find in apartments, although many of these models use filters that can be rinsed out with water when they get dirty and can be replaced less often.

We wanted this list to provide a variety of filters with different capabilities in a range of price points and available sizes. That being said, we felt that most homeowners' needs merit filters with higher MERV ratings, and so no item on this list has a rating lower than 8. This should be sufficient for cleaning indoor air to most people's standards, although it's best to ensure a higher-rated filter won't strain your equipment before using one for months and shortening the life of your blower.

Today we said goodbye to the Water Filter Tree due to availability concerns and added the reliable NaturalAire Eliminator, which not only offers a great value for money, but is economically-priced while still being on par with more expensive units.

Special Honors

Air Filters Incorporated Activated Carbon Those looking for industrial-grade carbon filters for contaminant and odor removal should consider the selection at Air Filters Incorporated. They offer exclusive Astro-Sorb carbon pleated filters that provide superior odor and particulate capture by using activated carbon combined with non-woven polyester media. Astro-Sorb is designed with residential and commercial HVAC industries in mind, with features including low-pressure drop, high dust holding capacity, and odor adsorption. These filters are suitable for removing VOCs, vapors, and gases from a manufacturing process or petrochemical application, and custom units are also available.

4. Honeywell FC100A

5. NaturalAire Eliminator

6. 3M Filtrete Ultrafine

7. Crisp MPR 600

8. Lennox X6675

9. Aerostar Pleated

10. CAS MaxMerv 9

The Dangers Of Indoor Air Pollution

Regardless, indoor air should be circulated and also filtered.

It may come as something of a surprise to many to learn that often the air inside your home is much more polluted than the air outside. This can be true even if you live in a crowded city or in an industrial area. Without proper ventilation, circulation, and purification, indoor air can be quite unclean and even unhealthy to breathe.

Indoor air quality, commonly abbreviated as IAQ, is a concern for all of us, but it is a matter of significant importance for the estimated 40 million Americans afflicted with allergies. Indoor air quality is also an issue of heightened sensitivity for the elderly, the very young, or anyone with an immune system compromised by an illness or condition. According to the World Health Organization, as many as 4.3 million people around the world pass away prematurely from exposure to household pollution. It's not a matter to be taken lightly.

The most common indoor air pollutants include microbial contaminants like bacterias and molds, smoke either from tobacco use or from cooking, radon, pet dander, and pollen blown in from the outdoors. It's important to be proactive in both preventing and mitigating indoor pollution problems.

This can be accomplished by regularly cleaning carpets and upholstery that can hold many contaminants easily stirred up into the air. It involves proper ventilation during cooking. When possible, smoking should be avoided indoors (or altogether) and any use of flame, as in a fireplace or wood burning stove, must see smoke sent up a chimney and away from living areas.

Ventilation is important, with exposure to fresh outdoor air ideal if you live in a region with clean air. Regardless, indoor air should be circulated and also filtered. If your home has an air conditioning system, it's imperative that you regularly clean and/or replace the AC filters. A clean filter is the difference between you and your family breathing clean air or breathing dirty air that just happens to be a bit cooler.

Choosing The Right AC Filter

When considering the right filter for your home or business's air conditioning system, first decide whether you want to use disposable or washable air filters. There are, as is to be expected, benefits and drawbacks to both options.

If you are willing to spend the few minutes to wash your reusable air filter regularly, you will enjoy the cleanest indoor air in this manner.

A disposable air filter tends to provide the best possible quality of air flow and filtration when it is first installed. Being brand new and in factory perfect shape, it will permit high volumes of air to pass with ease, meaning minimal strain on your HVAC system and great output from the vents. A brand new disposable filter also catches even the finest particles of mold, dander, pollen, and more. But many disposable filters tend to become laden with contaminants rather quickly. As a filter loads up with the matter it was designed to catch, airflow becomes less and less efficient, and eventually the air passing through the filter can be dirtied by exposure to the buildup there. At this point, the filter must be discarded.

Washable air filters will only provide the same high level of air filtration as a brand new disposable air filter at the first use. Thereafter, it will work well each time it is cleaned and put back in place, but it won't provide quite the same level of filtering quality. But a reusable filter can be rinsed off as often as you would like, thus achieving its relatively pristine state over and over. If you are willing to spend the few minutes to wash your reusable air filter regularly, you will enjoy the cleanest indoor air in this manner. Just make sure you follow the cleaning instructions that accompanied your reusable filter carefully so you preserve its proper function, and make sure to replace these reusable units at least annually.

Proper AC Filter Use And Maintenance

It's imperative that you select an air filter that fits your air return intake area perfectly. All HVAC systems installed in the past several decades should have one of a handful of opening sizes; take careful measurements and then determine the size of the opening. (It will likely be approximately 20 inches by 30 inches in an average sized residence, for reference.) A filter that does not fit snugly will allow air to pass by it freely, thus defeating the purpose of filtration in the first place.

The other approach is to opt for cheaper filters and replace them more regularly.

Most filters are designed with an intended airflow direction, so make sure to install the filter properly so it can function correctly. In most homes, replacing the air filter every two to three months is adequate, but take the time to visually inspect your air filter regularly until you have established your own residential (or business) needs.

Also take into consideration two different schools of thought. The first approach to air filter use is to choose a top quality filter that costs more but will last longer, performing well for the duration of its use. The other approach is to opt for cheaper filters and replace them more regularly. This second approach is often the better move for homes with multiple pets, because even a high quality filter that catches all sorts of minute particulate pollution can't do its job well when it is loaded up with hair or fur.

Brett Dvoretz
Last updated by Brett Dvoretz

A wandering writer who spends as much time on the road as in front of a laptop screen, Brett can either be found hacking away furiously at the keyboard or, perhaps, enjoying a whiskey and coke on some exotic beach, sometimes both simultaneously, usually with a four-legged companion by his side. He has been a professional chef, a dog trainer, and a travel correspondent for a well-known Southeast Asian guidebook. He also holds a business degree and has spent more time than he cares to admit in boring office jobs. He has an odd obsession for playing with the latest gadgets and working on motorcycles and old Jeeps. His expertise, honed over years of experience, is in the areas of computers, electronics, travel gear, pet products, and kitchen, office and automotive equipment.

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