Best Air Conditioner Filters: All Sizes Reviewed & Compared

Air conditioner filters are a crucial part of your HVAC system. Not only will a filter help clean and purify the air moving around your home, but it will also prevent contamination of the HVAC system.

Like almost everything else in life, you have a choice when it comes to the type and brand of your air conditioner filters. This article will examine the various types of filters and their specific abilities to help you decide which air conditioner filter you should purchase.

How AC Filter WorksAir filters have a seemingly simple job; filter the air passing through them. However, the tasks within the job are more involved. First, as the name and job imply, the filter does purify the passing air.

Various types of filters (discussed further below) will take on this job in a myriad of ways. The better the filter, the more particles it will collect.

The main focus though is to keep dirt, dust, and allergens out of the HVAC system. Not only will it help the cooler air being pushed around your home become cleaner, but it will also prevent build-up on the coils and inner workings of the system.

If dirt and dust are allowed to build-up on your evaporator coils or blower fans, air quality will dwindle.

You will also notice that a dirty system will produce foul odors, can clog the drainage pipes resulting in leaks, and can alter the perceived temperature making the system run more than it should.

Quick Guide – Our Top Picks

3 Benefits of HVAC Air Filters

Why should you invest time and effort into selecting the proper air conditioner filter? Here are three reasons to consider.

  1. Purify the air, reducing air born particles and can lower the number of allergens in your home.
  2. Protection for your HVAC system to keep it running properly, longer.
  3. Filters are a reasonable monthly expense that can reduce overall maintenance costs for your entire system.

Air Conditioner Filter Buying Guide

Know exactly what to look for in your next air filter purchase by following the advice in this buying guide.

Filter Size

The size of the filter must be such that it fits snugly in the filter receptacle. Most residential filters will be 1-inch thick but can vary in length and width from eight inches up to 48 inches (or more) and every number in between. There isn’t a one-size-fits-all filter size (exceptions made for customized filter frames), so you will need to measure or refer to your HVAC owner’s manual for the proper size.

Filter Type

Before you make a purchase, you will need to know what type of filter you are going to buy. From the list above, you also have to choose between filter materials. These are things like fiberglass, pleated paper, HEPA, washable electrostatic materials, or even filters containing activated charcoal.

Once you know the type, your air conditioner requires you can narrow down your choices. From there, you will want to look at the filter rating and filtration properties (see below).

Filter Rating

The filter rating is a system that tries to show you a numerical (or colored) value based on how long the filter will last and how many particles it will capture. There are three filter rating systems available: MERV, MPR, and FPR.

The FPR system was developed by Home Depot and is only available on filters they sell in-store. The Micro-Particle Performance Rating (MPR) was developed by 3M to enhance the MERV scale and rates HEPA quality filters (Filtrete and 3M Brands only) that claim to capture in-home allergens down to 1 micron in size.

The Minimum Efficiency Rating Value (MERV) is the original rating system and rates a filter’s ability to capture particles and hold on to them. In all three rating systems, the higher the number, the better the filter material.

Filtration Properties

When you look at the filter’s abilities, the filtration properties are the things you want or need the filter to collect. This can be things like mold and mildew spores, or pet dander, smoke or even odors.

Once you know what particles the filter should prioritize, you can adjust your purchase options. For instance, if no one in the house smokes, there is no need to pay for a filter that will filter out cigarette smoke.


Where budget is a concern, filtration of your air conditioner shouldn’t matter a whole lot. When you spend more, you get more. In most cases, the higher-rated, “better” filters will cost you significantly more than a thin, paper filter designed to fill a hole. However, the price will last you at least 90 days, spreading the cost out over three months instead of every four weeks.

8 Best AC Filters Reviewed

Here is our list of the best Air Conditioner filters reviewed so you can make a more informed purchasing decision.

1. Filtrete – Most Popular AC Filter

Filtrete is a 3M brand that is known all over the country for their dependable filters and high-quality materials. As an inexpensive disposable filter, Filtrete is one of the best. With an MPR (Filtrete/3M only) rating of 1100, the allergen-reducing filter will help purify your air.

The filter material is not washable and will last up to 90 days. For those in climates or regions with more smoke or smog in the air, you may want to replace the filters every 60 days instead.

2. Nordic Pure – Best Central Air Conditioner Filter

The pleated filters from Nordic Pure are the best option for disposable filters on the market. The MERV score of 12 means that the allergens in your home’s air will be captured, including pet dander, mold, mildew spores, and even pollen.

The cost-effective packs will allow you to have a year’s worth of filtration for the cost of 180 days worth from other brands. If you are looking for the best on a budget, Nordic Pure has you covered.

3. FilterBuy – Top Made in U.S.A. Filter

AC filter made in the usaFor homes that don’t have to worry too much about pollutants such as smoke or smog, the MERV 8 disposable filters from FilterBuy are an exceptional deal. The air will be filtered to keep the return clean as well as prevent dust build-up in the evaporator unit.

These filters are designed to be used with central and split AC systems as well as furnaces. Homes in regions with high pollen counts, or require filtration of cigarette smoke will need a higher quality filter.

4. AIRx Allergy – Best Air Conditioner Filter for Allergen Reduction

If you or anyone in your home suffers allergies, has asthma, or other breathing conditions, your home HVAC filter should be a top priority. Currently, there is none better than the AIRx ALLERGY filter. The AIRx filters are pleated with more surface area than most other pleated brands.

They also have an MPR rating equivalent to Filtrete’s 1200. This will capture smoke, smog, pollen, pet dander and a host of other allergy-inducing pollutants.

5. Honeywell (FC100A1029) – Best Pleated Replacement Filter

For those that have a customized filter or are looking for replacement material for an existing filter, Honeywell is the go-to brand. Not only will the material filter the air for your home and HVAC system, but it is also designed to be replaced in minutes so you can get back to having the air running.

The material is also pleated for a high surface area coverage in a smaller space. When purchasing, ensure your filter area can be covered with the correct amount of material.

6. Trophy Air Electrostatic – Best Washable Filter

If you are looking for a more permanent filter, Trophy Air is the way to go. The electrostatic filter is 100% washable and will dry quickly. You also don’t have to worry about airflow direction as this filter is bi-directional. Once you wash it and let it dry, you can put it back in place in any direction. The electrostatic filtration is completely porous so you won’t block airflow with a reverse installation.

Maintenance is simple, and Trophy Air has updated their sizing availability to ensure you get the perfect fit every time.

7. RV Air (AC 101G) – Best RV Air Filter

RV Filter vs Other FiltersWhen you are on the go in your RV, you don’t need to worry about air quality. The best RV air filter is the RV Air replacement material. It literally takes seconds to replace and will fit most RV air intakes. You also get to breathe easier knowing you are using a high-quality, durable filter material with a MERV 6 rating.

This filter material is ideal for a small space, even if you bring your pets with you. Pollen, pet dander and other larger particles are no match for the RV Air filter material and will not clog your airflow ducting.

8. EPAuto (CP285) – Best Automotive Cabin Air Filter

Most people are unaware that there is a small filter responsible for the air conditioning in their car. Aside from the air and oil filters in your engine compartment, you should also replace your cabin air filter.

The EPAuto filter is ideal for most applications and will provide clog-free airflow while capturing pollutants both internal and external to the car cabin.

Types of Air Conditioner Filters

Filters are an ever-evolving material. There are four major types of filters for air conditioners on the market today. Let’s take a look at them now.


Disposable filters are among the most common. They are inexpensive, easy to install or remove, and quick to change out. The disposable filters have varying amounts of filter material and can be effective for 30, 60, or 90 days, with some models even lasting up to six months.


Washable filters have stronger filter material and are more expensive than disposable types. However, they will last longer per filter. The main issue found with washable filters is the drying time. Since you should never run your air conditioner without a filter, we recommend buying two. Waiting until your filter is completely dry can cause problems.

Related ArticleCleaning AC Filters


Unfortunately, not all HVAC systems use the same size filter. Customizable filters fit the bill by allowing you to select the proper size with an adjustable frame. You then cut-to-fit the filter material, replacing as needed.

Deep Pleat

The more filter surface you can have, the longer the filter will last. It will also allow more airflow and clean more particles. Deep pleat filters maximize filter surface area without sacrificing thickness to allow you to double the filter size using the same space.

Filter Ratings Explained in Detail

The filter ratings will depend on the type and style of filter you purchase. All filters are required to use the MERV rating. However, 3M and Filtrete filters will also have the MPR rating, and Home Depot filters will be labeled with the FPR system.

As we mentioned, all systems use a numbering categorization where higher is better. The MERV system rates filters on a scale of 1 to 16. The higher the number, the more particles (and smaller the particle) the filter collects. Keep in mind that higher MERV numbers mean a denser filter material, which will become clogged with debris a lot faster. You will need to change out higher MERV rated filters more often than lower ones.

The scale doesn’t report on how well a filter performs but instead is the lowest number the filter receives in the worst-case scenario. What that means in laymen’s terms is that the number you see is the worst score possible for that filter, although in practice it will most likely perform better.

Furnace Filter vs. AC Filters: Are They the Same?

The short answer is yes, the furnace and air conditioner will use the same filter. They will at least use the same type of filter. In most cases, a residential system is set up as a central heating and air (HVAC) system.

In these cases, the air return duct is shared by a single unit, and there will be an individual filter. In split systems where the heating furnace is separated from the air conditioner, they will still use the same air inlet ducting, and thus the same filter.

The difference comes in when the systems are stand-alone. In this case, the furnace will use a different filter (two filters total) instead of a shared filter with the AC. However, the filters you purchase for the two units can be the same style and type, although they may not be the same size.

Washable vs. Disposable Filters

Should you go with a disposable, one-time-use filter or a washable one? This really is a personal preference, though your budget may have a say.

Washable filters are more expensive up front, but will generally last longer. While the initial investment could be quite high (depending on how many you need, the long term investment will save you a little bit of money.

The other factor to consider is the maintenance. With a disposable filter, you simply replace it with a new one. A washable filter will take time to clean, dry, and reuse. While it won’t take away your dinner plans, it is another chore that needs to be done.

One isn’t better than the other in terms of performance, only in personal preference. For those looking to lower their carbon footprint or reduce waste for the planet, a reusable filter is a good start. For convenience and affordability, disposable filters are the go-to option.

How to Change Your AC Air Filter

Once you locate the filter grate that houses the filter, changing it out is simple. Open the grating (usually a few push or pull tabs or even a set screw to remove) pull out the old filter and install the new one.

You should make sure the arrow on the filter frame points towards the HVAC system and not into the room. If you need more guidance on replacing your air conditioner filter, check out this short video.

Related ArticleChanging AC Filters Manually

People Also Ask (FAQs)

Have a question about air conditioner filters? We have the answers for you here.

What happens if the air filter is installed backwards?

Filters have a porous and non-porous side. You should take care to install so that the porous side faces the furnace or AC. Each filter will have a directional arrow for the airflow. Point the arrow toward the blower. If it is installed backward, the fan will have to work harder to create airflow which will, in turn, raise your energy costs and make the system more inefficient.

Where is the air filter in my AC unit located?

Air filter locations will vary from home to home. You should look for an air inlet grate in your walls or ceilings. In most cases, the grate will be near the furnace or AC itself. For a closet system, the grate is usually on the wall about knee-high. For attic installed systems the grate is generally in the ceiling in a hallway or bedroom.

Are there drawbacks to using AC filters with activated carbon?

The main drawbacks to activated carbon are replacement time and costs as well as the inability to filter some materials. Activated carbon filters don’t show signs of debris collection, so you have to keep track of installation date and replace based on the manufacturer’s suggestion. Carbon filters will not collect pollutants such as smoke, smog, pollen, or some other in-home air-borne allergens, which may be a concern for some homeowners.

Installing Filtrete FilterHow often should I change my AC air filter?

The time frame to change your air filter is determined by the type and style of the filter itself. Most disposable filters will range from 30 to 90 days. Washable filters are generally in need of a clean after 30 days and should be replaced every six months to a year.

How much does it cost to get my AC serviced?

While we won’t be able to tell you exactly how much an AC service repair cost will be, the national average, as reported by Home Advisor, is about $356. The overall price is based on the type of service needed, the amount for labor, materials, and unexpected findings. You should get at least three quotes from licensed repair or service centers before making a decision.

How much does a replacement air filter normally cost?

Again, the exact cost will vary from location to location and will have a number of determining factors such as filter brand, type, replacement interval, and where you shop. For a disposable filter, the average cost is between $10 and $30 per filter for a standard 90-day, paper filter.

Where are some good places to get these filters?

You can get air filters at almost any store that has a home improvement section. This includes local hardware stores as well as shopping online, you can find great online deals on air filters through:


Whether you need to replace your home, RV, or automotive air filter, you have choices. The most cost-effective filter is a pleated, disposable filter such as the Filtrete model mentioned above. A high MERV/MPR/FPR rating is essential to capture pollutants and protect your HVAC system.

Spending a little more on the filter will save you money on energy costs and expensive repair bills later on down the road. Take the time now to make the right decision for your home air quality and pick the filter that will work best for your home, your personal needs, and your budget.

Related ArticleHow To Clean Window AC Filter

Related ArticleHow To Clean RV AC Filter

Josh Mitchell

Josh Mitchell

My name is Josh and I am obsessed with DIY and improving my family home. HVAC topics can be tricky for homeowners so I decided to share my knowledge on the subject. When I am not working on DIY projects, you can find me at the beach or my local coffee shop.