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What makes up your homes AC filter and why does it matter

There is one important piece of information that (hopefully) everyone knows about HVAC filters —They need to be changed regularly. But outside of that, there is very little that most homeowners know about their home’s A/C filter. That seemingly inconsequential rectangle is actually an exceptionally important piece within the air conditioner. After all, all of the air that the A/C circulates throughout a home is first passed through those filters. So, it stands to question, what materials go into a home’s A/C filter? While it may not feel like much, there are actually several different materials that can be used for an A/C filter, and each one serves a different purpose.

MERV Ratings

Short for Minimum Efficiency Reporting Value, the MERV scale determines the basic effectiveness of any filter, ranking it on a scale from 1–20. Lower rated filters tend to filter out less, but also tend to be cheaper, with higher-rated filters filtering out much smaller particles, and costing much more. The basic breakdown is as such:

  • MERV 1–4: These filters are the most common and lowest cost filters, which filter out the most basic of substances.
  • MERV 6–8: These filters offer a greater level of filtration, and are the most common filters used in residential areas. These are where the pleated options begin to appear.
  • MERV 9–12: Going up the scale, this is the official “mid-range” filter, with high-quality materials able to filter out materials of 1 micron or larger.
  • MERV 13–16+: The most expensive, and most dense, filters available, these filters can filter out materials of 0.3 microns.

While it would seem most logical to always seek out the filter with the highest MERV grade, it’s important to verify that it will fit and function within a home’s HVAC system beforehand. Using a filter that doesn’t align with the A/C could make the system run inefficiently, or potentially work harder for lower air circulation, putting the whole system under greater wear and tear.


The filters in the MERV 1–4 range are made up of basic fiberglass material. They capture roughly 15% of overall filterable material and need to be replaced more often than other, higher-rated filters as they tend to wear out faster.

Pleated Filters

These filters have the wavy appearance of corrugated cardboard and tend to be made of polyester or cotton. Better than their basic fiberglass brethren, these filters tend to fall within the MERV 6–13 range, with cotton filters falling slightly higher on average than polyester. Pleated filters are able to stop up to about 45% of pollutants, come in the same size as fiberglass filters, and tend to need to be replaced every 1–3 months.

HEPA Filter

The highest-grade filters available, typically in the MERV scale range of 17–20, HEPA filters are capable of trapping 95% of airborne particles. While the most effective filter available, they are also the most expensive and can be impractical for some residential applications, as there are some residential HVAC systems that they will not fit with.

Washable Fabric

Some varieties of filters come in a washable fabric format, which can be much more convenient than the replaceable filters in some aspects. For instance, these filters tend to last for a number of years rather than a number of months. Conversely, homeowners have also expressed issues with these filters not typically seen in disposable or replaceable filters, such as mold and mildew growth over time.

Choosing the exact right filter for your home’s A/C can be a very involved choice — much more involved than more homeowners realize. At the end of the day, it’s most important to weigh the needs of the occupants with what filters can reasonably be used with your home’s system. If the option seems unclear, or if there is any question about which filter will match up with your home’s A/C system, consider reaching out to the licensed experts at Duane Blanton Family Home Services. Knowledgeable and experienced, the technicians at Duane Blanton will be able to help guide you toward the right filter for your home and system. To get in touch, give the technicians at Duane Blanton Family Services a call today, at (815) 781-2567, or check out their online scheduling portal from the convenience of your laptop or mobile browser.

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