Last Updated on January 28, 2021 by HVAC

Fiberglass Air Filters VS Pleated Furnace Filters

As the best furnace filters continue to advance, many people still choose to stick with their traditional disposable fiberglass filters. However, this no longer makes sense. Here is a quick overview of why you should throw away your fiberglass filter for the last time and pick up a new pleated filter.

Fiberglass Filters

1. Fiberglass Filtration Efficiency

Throwaway fiberglass filters have been proven to only hold a maximum filtration efficiency of 8%. This makes that useless for more than pre-filtering air or screening out the largest of airborne particulates. Within the industry, they are known as the “bugs and birds” filter. In fact, with their specific composition and spacing, they are not even technically classifiable as filters, but rather particle impingement devices.

With impingement, dirt and dust can only be caught if they directly strike or attach to a fiberglass fiber. A common demonstration that you can do in your own home is pour a packet of sugar over a fiberglass filter. The sugar will pass right through it.

And as you know, sugar isn’t even that small. It won’t “float in the air” as dust and other particles do. So how much do you really think is being filtered?

2. Maximum Capture Limit

Once dirt is captured at the front side of your fiberglass filter, the filter will eventually reach its maximum limit. At this point, additional particulate will then dislodge the already filtered dirt and carry it through the filter. In extreme cases, the filters themselves have actually collapsed and then the fiberglass particles are disbursed through the furnace or air conditioner and spread throughout the entire house.

Furthermore, even a brand new air filter will disperse some of its particles into the air says Champion Fiberglass. This is a major concern for those that have respiratory problems like asthma.

3. Don’t Touch the Fiberglass

Disposable fiberglass filters are notorious for dumping a ton of dirt and dust as soon as you touch it. If the filter is disturbed in any way, dirt will fly off of it (you have probably noticed this when replacing your filter). Just think about how much dirt you are putting back into the air, every time you change your fiberglass filter.

4. Mold and Bacteria

Recently, concerns have been raised because the adhesive that is used to bond the fiberglass to the frame of filter. The adhesive has been proven to be a very good place for mold and bacteria to attach and grow. This means that your filter is actually creating some of the most dangerous airborne particulate in the house.

Pleated Furnace Filters

1. Increased Filtration Efficiency

While fiberglass filters have proven to be at best 8% effective at filtration, pleated filters have an average efficiency of 25%-30%. Some have even been shown to have 45%-50%. That’s a HUGE difference!

2. Increased Air Flow

With increased efficiency comes increased air flow. Initially, this created a unique problem that lead to their current efficiency. To make the filters more sturdy, they use V shape pleating that increases the total square footage of the filter within the same frame size. This means that it is much more durable than a fiberglass filter and can filter out much smaller and much more particulate.

So if you do have any breathing problems, my personal recommendation is to find yourself a good pleated filter and get rid of your fiberglass one immediately.

3. The Rundown

The increased filtration leads to a serious of cause and effect benefits including:

Increased filtration efficiency leads to…

1. Increased Energy Efficiency because cleaner coils lead to more efficient heat transfer.
2. Decreased Housekeeping Costs – The house is cleaner, thus is cleaned less often.
3. Better Air Quality because it can filter out more pollutants as well as much smaller pollutants.
4. Less Maintenance because the HVAC system is kept much cleaner and consistently operates at maximum efficiency thus minimizing break downs.
5. Cost Savings – Electrical bills are decreased, plus you spend less on the filters themselves because they need replaced much less often.
6. Environmentally Friendly – Less filter changes means less production of filters and fewer filters making it to landfills and oceans.

There are many more advantages than these to choosing pleated furnace filters over their disposable fiberglass counterparts as well. It only takes a moment to realize which is the best choice.