The Three Popular Types of Air Filter Materials

Dig around inside your air filter (or in your HVAC system) and you’ll find it – the air filter media. This is the little strip of material that does the filtering for the system, catching any pollutants or allergens that pass through so they’re not recycled back into the air you breathe.

You probably know that already.

But what you may not know is that air filter media comes in several materials. Read on to discover the three most common materials used in these media.

Material 1 – Fiberglass

When spun into a thin fabric, fiberglass becomes one of the most cost-effective materials for air filter media. If you’re looking at a cheap filter, the odds are high that this is the material used for the media. But don’t mistake fiberglass for being an ineffective filtration media – it’s often among the most effective materials used in filters.


Fiberglass is great at catching the larger debris in your air supply (think dust particles and pet hairs) without blocking the air flowing through the filter.

Unfortunately, there are also downsides. As great as fiberglass may be for catching large particles, it’s not so great for catching microscopic organisms, like viruses and bacteria. It’s pretty flimsy, too, requiring you to replace the filter every 30 days rather than the standard 90 for other media.

Material 2 – Plastic

Sometimes dubbed “synthetic filter media,” plastic filters are usually made using polypropylene spun into thin strands before being bundled together to create a filter.

The benefits are obvious – polypropylene is tough and washable, so a single filter media can last for months whereas others need replacing every 30-to-90 days. Though a plastic filter media may cost more, you make that money back because you buy fewer of them.

Polypropylene is also free of BPAs, which is a dangerous form of synthetic estrogen found in other plastics, so you’re safe in that respect, too. But there is a downside, at least when compared to fiberglass – synthetic media has a lower surface area per gram than fiberglass media. Two times lower, in fact, meaning polypropylene isn’t as effective at keeping contaminants out of the air as fiberglass.

Material 3 – Activated Carbon

Activated carbon may seem like a strange choice of air filter. After all, “activated carbon” is essentially a synonym for charcoal – surely the last thing you want floating around in your air supply.

And yet, it’s surprisingly effective as an air filter media. Being an exceptionally porous material, it allows air to flow through it while catching small particles. For that reason, many consider activated carbon to be the safest air filter media, especially for getting rid of toxic gases and odors.



But, as with all filter media, it isn’t perfect.

The media’s thickness determines its effectiveness, with thinner carbon filters being less effective than thicker ones. Of course, more thickness means more space required, which can be a problem for small air filters and HVAC systems. Activated carbon filters cost more than fiberglass and synthetic filters, too, so they’re not especially friendly on your budget.

Material 4 – Pleated

Pleated filters are composed of a fabric medium, typically crafted from either polyester or cotton. This material is strategically folded to create pleats, effectively expanding the filter's surface area. Consequently, filters with a greater number of pleats exhibit superior efficiency compared to those with fewer pleats.

While pleated filters come at a slightly higher cost than fiberglass filters, their heightened effectiveness against contaminants justifies the expense. They excel at capturing even minuscule airborne pollutants like pollen, pet dander, and mold spores. Pleated filters are conveniently available in both disposable and reusable variants. Air Filters Factory provides disposable pleated air filters to consumers and business all over the United States.


Choose the Right Filter Media for Your System

Three filter media, each with its own pros and cons.

You know more about each, leading you to a final question – Which is the best air filter media for your air filter or HVAC system?

The answer depends on several factors, starting with your budget. Fiberglass is the cheapest upfront, with polypropylene saving you money in the long run. You’ll pay more for activated carbon, but you’ll also get a better filter media that can last up to six months (depending on its thickness).

Then, there’s performance – what do you need the filter to catch? Polypropylene is the worst performer in this regard, as it’s only good for larger particles. Fiberglass occupies a nice middle ground, with activated carbon being better for odors, gases, and tiny particles. Pleated is the best value for every home and business in the United States!

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