Air Conditioner Filters: What Are They Made of?

The air filter in an HVAC unit plays a very integral role. However, in most cases, it is overlooked and always treated as an afterthought. 

But, this shouldn’t be the case!

The air filter’s task is to get rid of solid contaminants and promote better air quality in your house. Such contaminants include pollen, grease, dust, pollen, and even harmful bacteria and pathogens. And with all the dangers that these contaminants pose to your household, this simple component becomes quite vital.

In this review, we shall learn more about AC air filters, see what materials they are made of, and understand how they help keep your indoor air clean.  

The Air Filter Overview

Basically, an air filter refers to a device used to sieve particles from the air. Just like in any filter, an AC one has a porous structure via which harmful particles cannot gain access. This way, these dangerous particles cannot access your indoor environment.

As such, these components are important for your household’s health and overall well-being. Some of the particles that an AC’s air filter handles are; dander or dead skin, pollutants from outside, fur from pets, dust, pollen, and mold.

What are Air Filters Made Of in Ac Units?

Now, an AC air filter’s composition varies depending on the type. There are different air filter materials as highlighted below;


It is the most famous material when it comes to HVAC air filters. And just like the name suggests, it has thin strands of glass. The glass fibers are merged together to create a rectangular or square-shaped HVAC filter.

One of the main reasons behind their popularity is their excellent filtration properties. They are able to get rid of the overly stubborn pollutants from the air. That way, the air getting into your house or office is contaminant-free.

Pleated Cotton

“What are pleated air filters made of?”, someone might ask.

And the answer — pleated cotton!

Pleated cotton is the same as the one used in other daily products. The cotton is formed and pleated into a filter for air filtration purposes.

Actually, they are more effective in getting rid of the pollutants in the air than fiberglass. On the MERV (Minimum Efficiency Reporting Value) scale, they are rated at six out of thirteen, which is relatively fair.

One benefit of this material is the ability to generate static electricity. When they produce this kind of electricity, the pollutants will stick to it, therefore, not reaching your indoors.

However, the pleated cotton air filters are very expensive compared to their fiberglass counterparts. Also, they have a shorter lifespan.

Washable and Reusable Material

Some HVAC filters are made from washable and recyclable materials. The materials are cloth-like and can be washed and used again after drying up.

However, while these materials are very affordable, they are created for low-intensity use. Subsequently, they have a 1-4 MERV rating, meaning they cannot make it in high pollutant environments.

Such material needs utmost care because it can easily get damaged. Also, before using them again, they should be completely dry. If not, fungi and mold will easily grow on them.


When looking for an HVAC filter, you will realize that some of them are marked as HEPA (High-Efficiency Particulate Air). This is not a specific material for your HVAC air filter. It means that the filter has been designed to get rid of 99.97% of particulate matter and must have a diameter of 0.3 micrometers.

The HEPA filters come in various materials. Some are made of plastic fibers while others fiberglass. Nevertheless, the individual fibers and strands of the material are combined to offer a higher level of air filtration. These filters have a rating of 13-16 on the MERV scale.

How Often Should You Change Your Air Filter? 

Changing your HVAC unit’s air filters should be a routine thing whether for your home or office. It will help ensure that your indoor space has ample and clean air circulation. However, the question that is always on homeowners’ minds is – how regularly should one replace their air filter

There is no definite answer here. However, for most HVAC units, changing air filters is generally required every three months. If you regularly change your air filters, you will be saving it from all the harmful particles like pollen, dust, mold, fungi, etc.

When it is time to change your air filters, do the following;

  • Buy the right size filter; to know the size of your air filter, examine the old filter. You should print the sizes on one of the sides of the air filter. If you cannot find the size of your old filter, use a tape measure to establish its length, width, and depth.
  • Switch off your unit; turn off the thermostat to switch off your unit. Alternatively, you can completely switch it off at the circuit breaker.
  • Find the filter; the air filter is usually found in one or two places; an air handler (located in the utility closet, basement, or attic) or in a return duct.
  • Remove the cover or grille to the air filter; open the access panel if your filter is in the unit’s air handler. Get a screwdriver to get rid of the small screws around it. Flip the latches that support the grille and get rid of them if it is in the return duct.
  • Do away with the old filter and insert another one; remove the old filter and note how it looks in the grille or cover. Place the new air filter inside, ensuring that the airflow arrows point towards the unit.
  • Restore the cover and switch on your unit; switch your unit back on after changing your filters and ensure that the filter is placed correctly. If the unit does not operate smoothly, reach out to an HVAC professional for assistance.

What are Air Conditioner Filters Made Of? — Conclusion

With this information at hand, you’ll not only be able to look out for the best material for your HVAC filter but also to change them. If you are unsure, seek assistance from an HVAC professional.

Leave a Comment

Your email address will not be published. Required fields are marked *

Scroll to Top