What Are The Best Air Conditioner/Furnace Filters?

An air conditioner filter is just that, a filter for your air conditioner and sometimes your furnace as well. The goal of this filter is to provide your home with clean high quality air. Along with that, the filter also serves a purpose by keeping your air conditioner and your furnace clean. The filter traps the dust, pollen, and any other debris that would otherwise be circulated through your system and your home.

What do they do?

Not only do they keep dust out of your home but they also keep dust off of the evaporator coils. The evaporator coils is where your cold air comes from. (In most cases the evaporator coil sits directly above your furnace inside your home.) If the coils are covered in dust and grime then the performance of your system is going to go down. You may also inadvertently damage the evaporator if you operate without a filter or with a very old filter. The more dust and grime that gets on your evaporator the less capable it is at removing heat. Some folks have their evaporator coils checked and cleaned each year as well as changing their filters regularly.

Not changing the filter can have effects on the performance of your air conditioner as well as longevity of your system. In some cases a dirty air filter can take away ten to fifteen percent system efficiency. This will end up costing you more money on your energy bills and could also end up costing you a whole lot if something fails in your air conditioner due to a clogged filter. A dirty filter can also affect the air quality within your home and could lead to problems for those in your family who suffer from asthma or other allergies. My father for example has severe asthma and they have religiously changed their filter every thirty days to prevent flare ups. He is especially sensitive to pet hair and by changing the filter religiously as well as buying a higher quality filter we are able to minimize any symptoms.

Quality of Your Air Filter

To understand the varying qualities of air conditioner filters you first need to understand the ‘MERV’ scale. The MERV scale, also known as Minimum Efficiency Reporting Value, is based on the percentage of particles from 0.3 to 10 microns in size that are filtered out of your system. The higher the MERV number on your filter then the better your air quality will be. Along with the MERV rating there is another measurement known as MPR or Microparticle Performance Rating. This MPR scale measures very small particles between 0.3 and 1.0 microns. Just like with MERV, the higher the MPR number the smaller the items that are filtered.

There are a variety of MERV sized air filters. To give you an example of the range let’s take a look below:

  • MERV One Through Four Filters – These are your lower end models that you’ll find in most grocery stores. While they do provide you with a filter, it is only the bare minimum. They can trap pollen and mold spores, but not near as well as higher rated filters. They are rated to remove particles over ten microns in size.
  • MERV Five Through Eight Filters – This is the next step up and will allow you to see a noticeable difference from the previous rung. These filters will allow you to remove agitants up to three microns in size. This would cover your pollen and mold spores as well as certain types of bacteria.
  • MERV Nine Through Twelve Filters – Now we’re getting into the higher quality air filters. These filters are rated to remove particles as low as one micron in size.  This could include such things as human hair, dust, pollen, mold, and combustion particles from candles or indoor fireplaces.
  • MERV Thirteen Through Sixteen Filters – Ok, folks this is the highest of the high for residential air conditioning and heating. With this rating we can get as low as point three microns. This covers nearly everything that there is including cooking smoke, paint pigments, fungal spores, and so much more.
  • MERV Seventeen Through Twenty Filters – I mentioned that the above was the best it could get for home air conditioning. Well, that was correct. However, this MERV measurement of seventeen through twenty is the absolute best possible and is typically reserved for medical applications such as hospitals and doctor’s offices. These filters are known as HEPA filters and are rated to remove up to 99.97% of particles that are point three microns or larger. These cannot be used in a traditional home air conditioner though due to the increased strain the system would go through pushing air through the filter. In some cases HEPA filters can be used in the home but only after extensive modification to the HVAC system.

Now, after reading this you may wonder what the right filter is for you. In most cases I would recommend the MERV nine through twelve categories. This gives you a high quality filter and will provide you with clean air throughout your home. If you have a family member, or if you yourself, struggle with asthma or other allergies then you may consider the MERV thirteen through sixteen filters. In extreme cases a HEPA filter and system may be needed, but this can get quite expensive as you will have to get a non-traditional residential air conditioning system to support the HEPA filter.

Good, Better, & Best

I can remember over twelve years ago when I started my career. One of the first things I learned from my former boss was what’s known as the ‘Good, Better, Best,’ approach. It is a sales approach that has always stuck with me as it just makes a lot of sense. In today’s world when you are searching for a product, it doesn’t matter what, you will find that there are dozens if not hundreds of choices and varieties.

The sheer amount of choices can overwhelm us. If there are one-hundred similar products and they are reviewed fairly high then what one do you choose? How do you distinguish between them? This is where the ‘Good, Better, Best,’ approach comes in handy. Instead of overwhelming the customer we provide only three choices for them.

The ‘Good’ choice is just that. It is a good product and will do what it’s designed to do. It does not have extra features or benefits. It is a basic product that will do what you want it to. The ‘Good’ choice is for your price based customers who are concerned about spending too much.

The ‘Better’ approach is the middle of the road choice. You get some extra benefits from the previous ‘Good’ option but it is not a top of the line product. There is still some price point consideration here.

Finally, the ‘Best’ approach is just that. It is the best choice out there. I like to think of this as the premium product. Yes, you will be paying quite a bit more than the ‘Good’ option but you are also getting a lot more quality for your money.

So, with the three choices mentioned above I am now going to ask you, what kind of customer are you? Are you price concerned, middle of the road, or a premium guy? Keep this in mind as we go through our air conditioner filter selections below.

The Good

Filtrete Air Filter MER 5
GOOD: Filtrete Air Filter MERV 5

Our nomination in the ‘Good’ category are the filters from Filtrete. These products have a MPR rating of three-hundred, or like we discussed in our quality section above, a MERV rating of five. A five MERV rating puts you towards the bottom end of quality but still allows you to remove pollen, mold spores, and other allergens from your home.

The chances are high that this filter will fit your system as when viewing the product on Amazon you can see that it comes in a wide variety of sizes ranging from 10X20 all the way to 25X25. Rest assured, you’ll be able to find the size you need. This product also comes in a six pack so if you’re changing filters every few months then you will be covered for a year.

Along with what I mentioned above the filter is highly rated on Amazon with over eight-hundred reviews and an average rating of four and a half stars out of five. You can’t go wrong with this filter especially if you’re looking for just a basic filter and you aren’t too worried about contaminant particles.

If you’d like to purchase this product click here to be taken to our Amazon partner. If, however, you’d like to read on to see what our nominations are for ‘Better’ and ‘Best’ then read on my friend, read on.

The Better

Ok, so in our ‘Better’ category we find a balance between a premium product and a lower end product. The point with this category is to give the price conscious consumer a middle of the road choice. Maybe they want something a bit nicer then the standard air filter but they don’t want to spend the money for a premium product. Whatever the reason may be, here is our recommendation for our ‘Better’ category.

True Blue Allergen Filters
True Blue Allergen Filters

We chose the True Blue Allergen air filters. These filters are the next step up and come with a minimum MERV rating of eleven. We are now double where we were when it comes to particle collection if you compare this product to the previously mentioned Filtrete. This filter will not only help you with allergens and pollen but it will also trap human hair, dust, and many other agitants that the lower rated MERV filters would miss.

The True Blue product on Amazon has nearly three-hundred reviews with an average rating of four stars. It also comes in a variety of sizes ranging from ten inch by twenty all the way to twenty-five to twenty-five inches. Also, when purchasing you’ll see that it comes in a four pack. Most HVAC technicians recommend changing filters every one to two months but this product states that the filter has a lifespan of one-hundred and twenty days. I am a bit skeptical of this and would still probably change after a few months… but even with changing every two months you still get eight months of usage out of your four pack.

If you’d like to purchase this product from our Amazon partner please click here. If you’re still looking for more then continue reading onto our ‘Best’ category.

The Best

Onwards and upwards to our ‘Best’ category. This filter will be the absolute best you can buy and will remove all particles above 0.3 microns. This could include everything we have mentioned above as well as cooking smoke, paint pigments, fungal spores, and so much more. You should be wary though that this product will be more expensive then what you are used to paying for air filters. This is the product that I would choose if I, or a family member, was having trouble with allergies or asthma while inside the home.

Nordic Pure Air Filters
Nordic Pure Air Filters

Our pick for the ‘Best’ category is the brand known as Nordic Pure. This brand and company are dedicated to providing the highest quality air filters to it’s customers. The products that we are going to link you to below ALL have a MERV rating of fourteen. That is one of the highest MERV ratings that you are going to find for a residential air conditioner. (There are HEPA filters as well, but we’ll get into that in our next section.)

These top quality products do not sell as well as the other two products we mentioned earlier. This is because of the cost involved, but do not get sticker shock when you check the prices on Amazon. You have to realize while yes the cost may be high these products are coming in large pack quantities. In some cases you are getting twelve to a pack. If you do the math per filter you’re really not paying that much more then you would for a standard filter. (That’s the benefit of buying in bulk!)

One downside when looking for these products on Amazon is that they are not neatly grouped together like our previous products. I imagine that this is due to the number of sales. If you are interested in purchasing this filter please click here, just note that you will need to find the right sized filter for you. (They are all Noridic Pure brands, just different sizes.) Rest assured, that if you do purchase you will be receiving a quality product.

HEPA Filters Honorable Mention

Many of you may have heard the term ‘HEPA Filters’ before. Usually when you think of this you think of an air purifier like the one found here. While there are many HEPA air purifiers on the marketplace there are also HEPA air/furnace filters. They work the same as the other products that we mentioned above except they come with MERV ratings starting at seventeen and can go as high as twenty. These types of filters are normally used in laboratories, medical facilities, and hospitals. These furnaces can catch viruses and bacteria and can help stop the spreading of diseases within the facility.

The downside of a HEPA air filter is that it can put a lot of extra strain on the air conditioner/furnace itself. The machine will have to push the air through that much harder. This can result in a overload and a burn out of a standard residential system. If for, whatever reason, you need a HEPA filter for your home air conditioner then you will need to do some retrofitting before you can use the filter. Otherwise, you risk damaging your entire system and being out quite a bit of money.


Your air conditioner and your furnace are some of the most expensive appliances in your home. It only makes sense to take care of them and to ensure that they last as long as they can. In today’s world a new AC and furnace could cost anywhere between six to twelve-thousand dollars. By ensuring that your air conditioner filter is taken care of every few months you not only protect your system and investment but it also provides you clean air throughout your home. If you aren’t already, please take the time to clean or replace air filters not only for your health but also for your wallet!