Fiberglass vs. Pleated Filters: Which Type of Air Filter is the Best?

It can be difficult when it comes to replacing your air filter because these days there are so many different options and categories from which to choose. FIberglass and pleated filters have become increasingly popular, however, for their simple disposable operation and promise of better air quality in the home.

What’s the difference between the two, though, and which one is right for your home? This article breaks down everything you need to know about fiberglass and pleated filters.

Fiberglass vs. Pleated Filters

Fiberglass Filters

Fiberglass filters are popular because, by and large, they are made with the most affordable materials and will cost homeowners less, even though you’ll need to replace them more often than with pleated or other types of filters.

Fiberglass filters are made from spun glass encased around a simple cardboard frame. The idea is that air will be pushed through these spun glass layers to force debris to stay on the filter while the clean air passes through. Fiberglass filters provide the least amount of air resistance to an HVAC system, which also means that their MERV ratings are very low, about 2-3. For those unfamiliar, MERV, or minimum efficiency reporting value, is a rating from 1-20 that quickly informs homeowners of the quality and efficiency of their air filters. Most of the time, any product from around 8-13 is going to be best for the home.

Accordingly, fiberglass filters have an innate weakness towards smaller dust and microbes, as the spun glass is not woven tight enough to stop them. In addition, since fiberglass filters catch most of their debris on their flat surface, removing a fiberglass filter is a tricky process. Too much agitation and the filter will release the debris back into the air before you can dispose of the filter. Fiberglass filters are often used in homes with low irritants, such as single-person homes or homes without pets. Their weakness in this department makes them more suitable for the budget-seeker rather than someone looking for the cleanest air possible.

Pleated Filters

Pleated filters, also known as paper filters or corrugated filters, are often sought out for their filter efficiency while still utilizing a disposable design. As the name implies, pleated filters are designed to resemble the folds of an accordion with several layers of fabric, often made of polyester or cotton, to filter out both small and large particles of dust and debris. This is because the increased surface area will have a large impact on dust control without decreasing HVAC efficiency. Most pleated air filters have a MERV rating of 6-13. The higher the MERV rating you choose, the more small irritants and allergens will be removed from the air.

Pleated filters are more effective, certainly, but that effectiveness will come at a higher price.Some HVAC systems will experience reduced output, however, by the strain of forcing air through the filter if too high of a MERV rating is used. In some cases, this can shorten the lifespan of the unit, which can mean increased expenses and wasted energy. Still, pleated filters appeal to homeowners with pets, kids, or specific allergy-based needs. When compared to fiberglass filters, there is no question that air quality will be better.

Quick Guide

Still not sure whether the fiberglass or pleated filter design is best for you? Consider the following pros and cons to both to help narrow down your choice:

Fiberglass Filters
ProsCons
  • Highly affordable
  • Less strain on the HVAC unit
  • Best for smaller homes with few allergens
  • Ineffective on small debris
  • Must be replaced monthly
  • Messy filter replacement
  • Low MERV rating
Pleated Filters
ProsCons
  • More effective filtration
  • Can come with electrostatic built-in
  • Last longers (3 months)
  • Great for pets/allergies
  • Higher MERV ratings
  • More expensive
  • Can put a strain on HVAC units

Final Thoughts

So, which is better: fiberglass or pleated filters? If we’re discussing the quality of air filtration, then there is no comparison: pleated filters are better. They offer more of a range in MERV ratings, help filter smaller debris that’s responsible for allergies and poor air quality, and perhaps most importantly pick up more dirt from the air. Fiberglass filters cannot compete.

That’s not to say, however, you need to rule out fiberglass filters entirely. If you’re on a budget and live by yourself or with one or two other people, you may not need the efficiency of a pleated filter. Still, pleated filters should be the default for many. Regardless of which filter you use, we hope that our guide can lead you to the filter (and the air quality) that you seek.

Further Reading