Fiberglass Filters vs Pleated Air Filters


What Are Fiberglass Air Filters?

Fiberglass air filters seem to offer a cheap solution when it’s time to replace your home furnace filters. I get it, sometimes you can find them in your local hardware store for less than $3 bucks a piece. That seems like a great deal but the problem is, those types of air filters aren’t very efficient. Their ability to trap a lot of the finer particles that plague your house is very poor. Due to their spun-fiberglass construction, particles like bacteria, viruses, and other allergens that are circulating through your home go right through these filters.

With a MERV rating of 1-4, fiberglass air filters can usually remove the largest of particles from the air like maybe some pet hair, dust bunnies, and cheerios but they are terrible at stopping the harmful particles from infiltrating your furnace and lungs. In households where someone has serious asthma or allergies, they’re almost the equivalent of not using a filter at all. 

When you look closely at a fiberglass filter, you can see huge spaces between the fibers. Particles smaller than those gaps will go right through this filter and clog up your HVAC system. Not only do the particles build up inside your furnace requiring extra cleanings, the toxins aren’t being removed from the air you breathe. 

Did you know that fiberglass air filters can get more efficient the longer they are installed in your system? Ironically enough, even though they still tout the same 30-90 day replacement recommendation printed on the filter or packaging as a pleated MERV 8 filter does, they can actually get better at trapping finer particles with time. But to start off, they let most of the lung-damaging particles right through.

Think about it, they are so bad at stopping dust from going through them the first time they actually become better air filters the more they load up with debris. The layers become more dense thus filtering more effectively.

Now, I would never recommend someone leave an air filter in their system for 6-12+ months just to become as efficient as say, a MERV 8 air filter. Any air filter can get pretty disgusting after some time. I mean, what you see collected in its fibers is going to be made up of mostly dead dust mites, dust mite poop, your own dead skin cells and body hairs just to name a few things.

At a minimum, for your health and the health of your HVAC system, it’s best to always use an air filter rated MERV 8 or higher. When you compare a MERV 4 vs MERV 8 filter side by side you will find a tremendous difference in particle trapping. This does mean that an air filter with a MERV rating of 8 or higher can get dirtier quicker but it also means spending less money on cleaning your furnace, less time dusting your furniture and less doctor visits if someone in your household is affected by allergies.

Which Furnace Filters Contain Fiberglass?

We can’t speak for all high MERV air filters but our furnace filters do not have any fiberglass in them. Our filters are hand made in the USA and are made of the highest quality. The filter material is made up of a mixture of cotton and polyester fibers surrounded by a heavy duty- moisture, mold and mildew resistant cardboard frame.

All of our air filters are rated MERV 8 or higher while filters containing fiberglass are usually rated MERV 4 and lower. This doesn’t mean that all MERV 8 and up pleated filters are fiberglass free. You should always ask the manufacturer if you have questions about the specific materials used in production if your health depends on it.


What is a MERV rating?


MERV stands for Minimum Efficiency Reporting Value and is a standard of measuring how much air filters can catch and trap fine airborne particles. The smaller particles you may see floating in your air are the usually the allergens, virus carriers and lung-damaging particles that set off sinusitis and respiratory illnesses. These particles are floating in your air because they are positively charged- and so are you walls, your ceiling and your floor. So there they stay, suspended like a mini solar system sometimes dancing when the air gets disrupted. Eventually movement in the air will cause these particles to circulate through your HVAC system. As they do, they will pass through your air filter(s) removing smaller and smaller particles depending on how high the MERV rating is.

Air filters are ranked on a MERV scale of 1-20, the higher the number meaning the finer the particles it is able to filter from the air. While a hospital or surgery room may need MERV 20 rated air filters to maintain a healthy environment, usually MERV 13 is the highest grade air filter recommended for residential home furnaces and HVAC systems. Finding the right MERV rating means finding the right balance between a filter that can remove the most allergens without sacrificing air flow.

What is MERV 8?

MERV 8 filters are pretty much the standard for homes that care about air quality and the life of their HVAC system. When you step up to a MERV 8 rated air filter you are now able to filter out most pollen, dust and lint, dust mites and their harmful poop, and most pet dander. In fact our MERV 8 air filters are up to 20 times more effective at catching these finer particles than fiberglass filters are. For ususally just a few dollars more you can do yourself a much better service by investing in a finer filter for your lings and the internal components of your HVAC system.

MERV 8 vs MERV 11

MERV 11 air filters can remove even finer particles that include bacteria sized particles along with mold spores and car fumes. We recommend MERV 11 filters if you have allergies to normal household dust and pollutants. When you shop our MERV 11 filters, you will find that they are up to 30 times more effective at trapping lung damaging dust than fiberglass air filters.

MERV 11 vs MERV 13

This is where it usually gets tricky. MERV 13 is the highest recommended MERV rating for home furnaces, heat pumps and HVAC systems. Not only can it help new buildings qualify for LEED certification, it is recommended for homes with babies, elderly, severe allergy sufferers and smokers due to the amount of damaging particles it can remove from your air. Our MERV 13 air filters are more than 30 times more effective at trapping micro-particles than fiberglass air filters and maintains the same airflow as our MERV 11 filters. To learn more, check out our MERV rating chart here

Why Paying Less Isn’t Saving You Money

Paying less for low-quality air filters isn’t a good money saving option in the long run. You’ll pay for that mistake elsewhere, whether it’s on your utility bill, in HVAC system repairs, or even health care costs. explains that heating and cooling takes up more than half of a typical electricity bill and says average homeowner uses up 54% of their total electricity on heating and cooling a home. That’s why it’s important to regularly change your air filters in order to keep your system working at peak efficiency. Using high-quality air filters, a programmable thermostat and making sure air flow isn’t being blocked by furniture or drapes are important steps to take toward reducing your energy bills. 


High-Quality Filters are Safer

High-quality air filters provide several things cheap fiberglass filters just can’t. The higher MERV rating means that smaller particles are being trapped instead of being in free flow circulation. Fiberglass filters can get rid of dust and debris, but they can’t trap mold particulates and other small particles that are prone to trigger asthma and allergy attacks. People can literally breathe easier in homes that use air filters with higher ratings because MERV 8 rated filters can remove smaller particles like hairspray, MERV 11 can remove auto emissions and lead dust, and MERV 13 can remove all types of bacteria and most tobacco smoke.
When you’re shopping for air filters and you see incredibly cheap prices on those fiberglass air filters, remember that you’re getting what you pay for—next to nothing. Those filters provide minimal filtration when they’re brand new, and once they’ve collected any amount of dust, their efficiency is even further reduced. Choosing high-quality filters is always the healthier and most economical choice in the long run. Click here to shop our filters and add a better filter to your HVAC system with cheaper than box store prices.


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