Not All Filters Are Created Equal. The HVAC Filter Hierarchy Explained

The amount of HVAC air filters on the market is downright overwhelming. They can run the gamut from the affordable—albeit ineffective—fiberglass filter, to HEPA—which are considered the Cadillacs of the HVAC air filter world. We understand how easy it is to get lost in a sea of reviews and recommendations. Therefore, we’re sharing the differences between the most common types of HVAC filters to help you navigate the dizzying field of choices.

How Many Different Types of Air Filters Are There?

There are more air types of air filters than we can list, but for the sake of brevity, we’re sharing the 7 most common air filters, they are:

• Fiberglass Filters
• Pleated Filters
• HEPA Filters
• UV Filters
• Electrostatic Filters
• Washable Filters
• Media Filters

Each of these filters does a specific job. The one you want in your home depends on the type of job you want it to do. Some households have a lot of pets and need a filter that will remove pet dander. Other homes have people who suffer from asthma and allergies and would pick a filter based on that criteria.

The air filters we’re talking about are all made from different materials. Almost all of them, except a HEPA filter, have a MERV rating as well. MERV stands for Minimum Efficient Reporting Value and scores filters from 1 to 16 based on how well they can trap indoor air pollutants. The higher the MERV rating, the more airborne contaminates it will catch. For example,

• Filters with a MERV rating between 1 and 4 will catch things like pollen, dust mites, and carpet fibers.
• Filters rated between 5 and 8 will catch everything listed above, as well as mold spores and indoor air contaminates from things like fabric protector and hair spray.
• Any filters with a MERV rating between 9 and 12 can catch everything listed between ratings 1 through 8, and lead dust, humidifier dust, and pollution from auto emissions.
• And finally, filters with a rating of 13 to 16 will filter bacteria, tobacco smoke, sneeze particles and everything else listed above.

Fiberglass Filters

The first filter on our list is the most used air filter on the market. Fiberglass filters are popular because of their price-point and availability. These filters can be found at any hardware or home improvement store and are even sold for less than a dollar. However, when it comes to filters you get what you pay for.

Fiberglass air filters have a MERV rating that falls between 2 and 4. This means fiberglass air filters are not great at catching things like dust, dander, and any other allergens. Another downside to fiberglass air filters is that they need to be changed more often than other types of filters. They have a small surface area and are unable to hold a large amount of particles. This issue offsets the low cost. You’re paying less for an air filter, but it needs to be replaced more often.

Pleated Filters

After fiberglass filters, the most common filter on the market is a pleated filter. These filters are made with sheets of cotton, paper, or polyester. The sheets are folded into pleats so they have a larger surface area and can effectively snare more air contaminates and particles.

Another perk of pleated filters is that they do not need to be changed as often as fiberglass filters. Though they may cost slightly more than fiberglass, they hold more value because they last longer. Pleated filters have different MERV ratings. There is no blanket rating. The assigned rating is based on the material and construction. For example, a pleated filter rated an 8 on the MERV scale can block pollen, dust, and pet dander. Whereas a pleated filter with an 11 rating can block pollen, dust, pet dander, mold spores, smog and car fumes.

HEPA Filters

One of the most interesting things about HEPA (High-Efficiency Particulate Air) filters is that they do not have a MERV rating. HEPA filters are so strong they’re in a category all their own. Made from multiple layers of tightly wound fiberglass strands, HEPA filters can catch 99.9% of indoor air contaminates. In fact, HEPA filters are so strong they’re used in hospitals and heath care facilities.

A home with people who deal with allergies and asthma would greatly benefit from a HEPA filter. Despite this, a strong air filter isn’t the end all be all for keeping allergies at bay. In addition to a strong air filter, homeowners should frequently vacuum and dust and routinely change bedding to help combat allergens.

One drawback of HEPA filters is that not all HVAC systems can fit a HEPA filter. Sometimes these filters are larger than traditional filters and won’t work with conventional HVAC systems. Because of this be sure to ask your HVAC tech which filter is best for your current system.

UV Filters

When we say UV filter, we really mean a UV purification system with an additional air filter. The idea of only a UV light being able to clear the air is nice. It unfortunately doesn’t work that way. The UV purifications systems used in HVAC target viruses, bacteria, and other microscopic organisms that make you sick. What they don’t target is dust, dander, pollen and larger particles.

UV lights for HVAC are interesting. They’re usually placed right above the air filter and act as an extra layer of protection for everyone in your home. When a harmful particle passes by the UV light, rays target and almost “zap” the particle, causing it to fall out of the atmosphere.

We recommend a traditional pleated filter with a UV purifier for the most optimal HVAC setup. A pleated filter will catch larger particles like pollen, dust, and dander, while the UV purifier will kill any viral or bacterial air contaminates.

Electrostatic Filters

You know how static can make things cling to your clothes? Now think of that, but with dust and indoor air contaminates. Electrostatic filters use static as a magnet to pull particles from the air. An electrostatic filter is best suited to a home with small children or pets.

Electrostatic filters can be disposable or washable, it all depends on the type you buy. The MERV rating also depends on the individual filter. Like everything else, not all electrostatic filters are created equal. Some can have a lower or higher MERV rating, it all depends on the material.

Washable Filters

Sustainability is something we hear more of our clients asking about. Some are unhappy they need to change out and ostensibly waste materials when they could have a more sustainable option. While washable filters have a lot of pros, they also have significant drawbacks.

The best thing about washable filters is that they keep more stuff from ending up in a landfill. The upfront cost for a washable filter may come as a shock to some, but over time a reusable air filter will pay for itself. A washable filter is not the best option for anyone wo suffers from asthma or allergies. The materials washable filters are made of cannot effectively trap things like pet dander or pollen.

Another thing to keep in mind is that you need to let a washable filter completely dry before putting it back in your HVAC unit. Putting in an air filter that’s still moist could lead to mold growth; no one wants to be breathing that in.

Media Filters

A majority of the filters we included here are only an inch thick. On the other hand, a media filter is around eight inches thick, which means you’re getting seven more inches of protection for your indoor air.  Because of their heft, media filters can provide you with the same quality air as a high-MERV filter, but without some of the drawbacks like reduced air flow or static pressure.

The larger surface area of media filters means they prevent static pressure, dirt, dander, and other debris from entering your home. A complaint we hear though is that a professional must install this filter. Because of their size, media filters are best left to someone who knows how exactly to install them.

The only other complaint people have about media filters is that they don’t filter smells like smoke or cooking odors.

Want to Learn More about HVAC Filters? Speak with the Experts at Service Champions

Do you want to elevate your indoor air quality? If so, schedule an appointment with an HVAC expert from Service Champions. Our technicians receive yearly training to ensure they are up to date with the latest HVAC innovations. We are the only Diamond Certified plumbing and HVAC company in Southern California and proudly serve areas of Los Angeles, Riverside, Orange, and San Bernardino county. Call the number at the top of the screen or click here to book an appointment online.