4 Types of Whole House Air Filters (2023)

When it comes to air pollution, there’s no place like home. Today’s tighter houses keep the weather outside, but they also keep contaminants inside. According to the Environmental Protection Agency, the air indoors where we spend as much as 90 percent of our time can be more polluted than even city smog.

And dirt you can see is just the beginning. That dust collecting on end tables and bookshelves is only a fraction of what’s actually swimming around in the air: an invisible mix of dust mites, pollen, dander, mold, and smoke that can be annoying to breathe and hazardous to your health.

The first line of defense against airborne contaminants is to keep a house clean and well ventilated. But for some sensitive people that may not be enough. That’s where air filters come in.

How Do House Air Filters Work?

Household air filters are available in two basic types: media filters, which create a physical barrier that traps minute particles, and electronic filters, which use a high-voltage charge to attract and capture contaminants.

A few air filters are hybrids that combine both methods, and some include activated carbon elements to combat odor. Learn about the types of air purifiers below.

Typically, air filters are either built into the heating and cooling system (whole house filters) or are freestanding units that can be placed in individual rooms (portable filters with self-contained fans).

4 Types of Whole House Air Purifiers

Whole house filters, like the extended media filter shown here, must be professionally installed in return-air ductwork. Photo by Keller & Keller

The most efficient way to filter household air is through your home’s forced-air heating or central air-conditioning system. The filters are built into the return-air ductwork, trapping particles as air passes through.

Such systems are passive; as long as the fan is running, they are constantly filtering all the air in your house. Whole-house purifiers come in four main types.

1. Flat Filters

4 Types of Whole House Air Filters (1) Photo Darrin Haddad

If you have a forced-air furnace, you’ve already got a rudimentary air-filtration system: That matted-fiberglass filter that should be changed once a month. “You can’t change it often enough,” says This Old House plumbing and heating expert Richard Trethewey.

When it clogs with dust, it stops working and overworks the furnace. In fact, those filters are designed to protect your furnace from large particles of dust, and while they might keep surfaces in your house a bit cleaner, they won’t block the microscopic particles that are most irritating to lung tissue.

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Pleated filters, which pack more material in the same amount of space, cost a few bucks more and do a slightly better job. By far the best-pleated filters are electrostatically charged to attract allergens like pollen and pet dander. They cost around $15 and should be changed every two to three months.

2. Extended Media Filters

4 Types of Whole House Air Filters (2) Photo Darrin Haddad

Picture a stack of furnace filters about 8 inches thick and you get the idea of an extended media filter. These boxy units contain an accordionlike pile of filtration media, which makes them more effective than regular fiberglass filters.

They require professional installation because the large filter holder must be plumbed into the ductwork. The price, including installation, ranges from $400 to $600; you’ll need to replace the $40-to-$60 filters every year.

3. Electronic filters

4 Types of Whole House Air Filters (3) Photo by Darrin Haddad

These high-tech units, sometimes called electrostatic precipitators, are also incorporated into the ductwork. As air passes through, a high-voltage current puts an electrical charge on particles. At the other end of the unit, oppositely charged collector plates grab the particles like a magnet.

Electronic filters work especially well on smoke particles too small to be trapped in media filters. One independent test found such filters worked about 30 times as well as regular fiberglass filters. (There is no industry yardstick for measuring the effectiveness of whole house units because performance is affected by a home’s blower and ductwork.)

Unlike media filters, electronic filters never need replacing, but the aluminum collector plates must be cleaned in soapy water every few months. The process of charging particles, called ionization, may produce trace amounts of ozone, a lung irritant. Electronic filters cost $600 to $1,000 installed and require a 120-volt electrical outlet.

4. Ultraviolet Filters

4 Types of Whole House Air Filters (4) Photo Darrin Haddad

People worried primarily about germs can consider an ultraviolet filter. Typically, UV filters are built-in components, sold as add-ons to a whole-house electronic precipitator (as in, add on $400 to $800).

The ultraviolet light zaps airborne bacteria and viruses into oblivion, which is why hospitals use UV air filters in tuberculosis wards. Of course, the bug has to reach the filter before it can be zapped; if someone sneezes in your face, UV technology won’t help.

Portable Room Air Filters

4 Types of Whole House Air Filters (5) Photo Darrin Haddad

If your house has no central air-conditioning or heating, portable room air filters are the most practical choice. Freestanding whole house units exist, but they typically require attic installation and ducting to individual rooms.

Most portables employ highly effective HEPA filters, which are not generally used in whole-house systems because they need more-powerful fans than furnaces can provide.

Some portable units, called ion air cleaners, use electrostatic precipitator technology. Ion units, which don’t require fans, are typically quieter than HEPA models and cost less to operate because there are no filters to replace. But these units may produce trace amounts of the lung irritant ozone as a by-product of the ionization process

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Portable units range in price from $150 to as much as $1,500, and there are ongoing costs. HEPA filters, which must be replaced annually, cost from $40 to more than $100.

Portables can also be noisy because it takes a lot of wind to push air through such a fine filter. Some manufacturers are addressing the noise issue with so-called smart filters that employ an optical sensor to judge when the air is relatively clean, then switch to a lower fan setting. Another strategy is to run a portable filter on high during the day, then turn it to low at night.

Portables powered by fans are rated by “clean-air delivery rate” (CADR), which measures both air movement and gunk-trapping effectiveness. It’s important to buy a filter that’s big enough. Manufacturers recommend that the CADR be at least two-thirds the room’s area in square feet — so a 15-by-20-foot room (300 square feet) would need a filter with a CADR rating of 200. (The calculation assumes 8-foot ceilings.)

Portable Ion Units

Portable ion units are similar to whole-house electronic filters in that they both put an electrical charge on particles.

In a whole-house system, the particles of dust and pollen are charged as they pass through the unit, then captured on an oppositely charged collector plate. Portable ion filters, which operate without fans, send streams of negative ions directly into the air.

Charged airborne particles are then attracted to a collection rod in the unit (which needs occasional cleaning), or with some models allowed to land on surfaces in the house (where dusting removes them from the room).

Pro2ProTip: Ion air filters should not be confused with ozone generators, a different type of air filter that relies on ozone to clean the air and is not recommended by the EPA or the American Lung Association.)

As a by-product of the ionization process, these types of units may produce trace amounts of ozone, a lung irritant.

Ion filters are considered safe if they release less than 50 parts per billion of ozone, the government’s threshold. But even smaller amounts could bother people with asthma or other breathing disorders.

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If you’re considering a whole house or portable electronic filter, check the product specifications to make sure it does not exceed safe levels for ozone emission.

Getting Hep to HEPA

High-efficiency particulate air (HEPA) filters were invented during World War II as a way to prevent radioactive particles from escaping laboratories.

The filters are made of various synthetic fibers; there is no construction standard because the term merely designates an efficiency rating: the ability to block 99.97 percent of all particles 0.3 micron or larger.

Note: A micron is a millionth of a meter, or .000039 inch; the naked eye can’t see anything smaller than about 25 microns.

That rating is for laboratory conditions, however. Experts say that at home you can realistically expect a HEPA filter to grab about 80 percent of such particles.

A new filter technology for the home, called ULPA (ultra-low penetration air), has raised the stakes. ULPA filters block 99.99 percent of particles measuring 0.12 micron, quite a bit smaller than the HEPA threshold. But ULPA filters restrict so much airflow that in practice they are able to clean less air than HEPA filters. For best performance, look for those labeled “true HEPA.”

But Do They Really Make You Feel Better?

Air filters, in general, do a good job of clearing the air. But do they actually make you feel better? The medical verdict is still out.

According to Andrew Filderman, M.D., a pulmonary specialist in Rockport, Maine, no controlled studies have been done on the subject. “We know these things filter the stuff, but we don’t know if it helps,” he says. “It’s difficult to prove because there are so many provocative things in the air, and you don’t always know what’s causing the problem.”

Dr. Filderman adds that while some allergic or asthmatic patients report benefits from air filters, the evidence remains anecdotal. “If source control and ventilation don’t help,” he says, “it’s not unreasonable to try a filter.”

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Where To Find It

Flat Furnace Filter

Fiberglass-mesh and standard pleated
Chicago, IL

Extended Media Filter

Model# 2200

Electronic Purifier

Enviracaire Elite F300E
Morristown, NJ

UV Filter

PureAir Air Purification System
Richardson, TX

Portable Air Purifiers

Blueair 501
Blueair, Inc.
Provided by Pure n Natural Systems, Inc.
Morton Grove, IL

Whispure Model# AP25030H

(Video) Types Of Air Filters: How To Choose The Best Air Filter For Your Home


What are the four types of air filters? ›

Air Filter Types

Fiberglass, polyester, washable, pleated and electrostatic filters each offer different air filtering capabilities. Electrostatic filters provide the highest level of filtration for small particles. Tip: While most filters are disposable, some may be cleaned with water or by vacuum.

What are the different types of home filters? ›

High-efficiency particulate air (HEPA) filters are recommended by the U.S. Department of Health because they are able to remove at least 99.97% of airborne allergens and pollutants — including mold spores and dust that are as small as 0.3 microns.

How many types of air filters are there? ›

7 Main Air Filter Types. The primary difference between air filter types is their ability to filter various air-borne pollutants present in your home.

What are the 5 types of filters? ›

There are many different types of filters used in electronics. These filter types include low-pass, high-pass, band-pass, band-stop (band-rejection; notch), or all-pass. They are either active or passive.

What are the types of air filters in HVAC system? ›

Different Types Of HVAC Filters Explained
  • Fiberglass Air Filters. Disposable, most affordable yet with the lowest straining ability of all the types are fiberglass air filters. ...
  • Pleated filters. ...
  • Washable Air Filters. ...
  • Electrostatic Air Filters. ...
  • HEPA Filters. ...
  • UV Filters.
28 Sept 2017

What kind of whole house filter do I need? ›

A large filter is the best, as it means increased water supply and longer service interval. You also need to check the port size of the filter since it impacts the gallons per minute and the pressure of water that flows into your house. For an average home, the ideal size of a whole house filter should be 4.5″x 20″.

How often should a whole house filter be changed? ›

Though it costs more to install a whole house water filter, you won't have to think twice about the water quality throughout your home. A whole house water filter should be changed every three to six months. Learn more about when to change your whole house water filter.

How long do whole house filters last? ›

On average, whole house water filters will last for the following lengths of time: Pre-Filter: Three- to Six Months. Carbon Filter: 12 Months. Post-Filter: Up to One Year.

How many air filters does a house have? ›

How Many Air Filters Does a House Have? Typically, a house will have 2 air filters in their intake vents. In some cases, there can be more or fewer depending on the square footage of the home or apartment and the number of floors that need to be supported by the central air system.

Are whole house air filters worth it? ›

For those with allergies, asthma and other respiratory conditions, a whole house air purifier is undoubtedly worth the money. The system helps reduce symptoms by removing antagonistic air pollutants. This results in less frequent and less intense allergy and/or asthma attacks.

What is the most common type of air filter? ›

Fiberglass air filters are the most common type of air filter. These are disposable and are extremely affordable. Originally, fiberglass air filters were developed to protect your HVAC system, not to trap dirt and other contaminants.

Which is the most powerful type of air filter? ›

Air purifiers employing HEPA filters -- defined by the US Department of Energy as high-efficiency particulate air filters that are capable of removing at least 99.97% of airborne particles with a size of 0.3 microns -- are the most numerous and most highly rated type available.

Which filters are most commonly used? ›

1) UV Filters

Today, UV is the most widely commonly used filter, but now its role is different. It serves mainly to protect a lens from scratching and damage. Every photographer who cares about their equipment should use a UV filter.

What are the types of HEPA filters? ›

According to the Institute of Environmental Science and Technology, (IEST) with regard to performance, there are 6 types – A, B, C, D, E & F. Each has its own distinct characteristics as shown by chart 1 below.

What are 7 common types of filters in communication? ›

What are Some Common Types of Filters in Communication?
  • Distractions.
  • Emotional states.
  • Beliefs and expectations.
  • Differences in style.
  • Self-protection.
23 Sept 2021

What are the different types of filtration systems? ›

The 5 Types of Filters
  • Mechanical Filters.
  • Absorption Filters.
  • Sequestration Filters.
  • Ion Exchange Filters.
  • Reverse Osmosis Filters.

What filters do HVAC techs recommend? ›

HEPA Filter — HVAC replacement companies typically recommend HEPA filters because they can provide the highest protection level when it comes to airborne particles. This filter is capable of capturing small microns, and has a MERV rating between 17 and 20, meaning it can trap tobacco smoke and bacteria.

What is the most efficient HVAC filter? ›

Pleated: MERV 10-13

Made from cotton or polyester, pleated filters are one the most popular and efficient filter choices. Their effectiveness, however, varies upon pleats per foot. For a pleated filter to have an efficiency rating of 10 to 13, it should have at least 18 pleats per foot.

What is the most common furnace filter? ›

Here are some of the most common furnace and AC filter sizes:
  • 10 X 20 X 1''
  • 14 X 20 X 1''
  • 16 X 24 X 1''
  • 18 X 30 X 1”
  • 20 x 20 x 1.
  • 16 x 25 x 1.
  • 20 x 25 x 1.
  • 20 x 25 x 4.
16 Feb 2022

What Merv is best for home? ›

In general, the best MERV rating for a home is somewhere between 8-10. These filters will capture a large portion of the airborne particles and improve indoor air quality without making your energy costs rise significantly.

Are whole house carbon filters worth it? ›

Whole-house systems with carbon filters are the most economical option, and they also require the least maintenance. These filters generally don't need to be replaced for at least three years, and they remove one of the most common contaminants: chlorine, which reduces the chance of poor-tasting water.

Do I need a whole house UV filter? ›

Whole House UV systems are highly recommended to homeowners who may suspect E. coli, cryptosporidium, giardia or any other types of bacteria and viruses in the water. Ultraviolet (UV) technology is more effective than chemicals in destroying certain waterborne contaminants and is safe and chemical free.

What is the average cost of a whole house water filter? ›

According to Angi and HomeAdvisor, a home water filtration system costs between $1,000 to $4,000, with a national average of $2,078.

Why does my whole house water filter get dirty so fast? ›

It's possible that you're simply dealing with water that's too dirty by default. In this case, it will cause additional wear on whole house filters and decrease their lifetime faster than intended. There's not much you can do here, other than to take note and make sure to replace your filters more often in the future.

Why do my house filters get dirty so fast? ›

When the thermostat's fan setting is set to “ON” the indoor blower will run 24/7, constantly circulating air over the air filter. So now the filter is constantly catching airborne contaminants, causing it to quickly get dirty.

Can I run my HVAC without a filter for one day? ›

The short answer: You can get away with running your AC without a filter for a short period of time. However, doing so for longer than 6-8 hours can hurt your system and decrease your home's indoor air quality.

Can you clean whole house filters? ›

For the whole house filter, you'll want to empty the mineral bed. Clean the entirety of the unit with a combination of water and bleach. Always use proper precautions when cleaning with bleach.

What happens if you don't change filter in house? ›

A dirty filter reduces the airflow to your HVAC system and causes it to work harder. It uses more energy, which costs you more money. It also might not be able to keep your home at the proper temperature. This means it may have to run for longer periods, which strains the system.

What filters in a house need to be changed? ›

In general, replace HEPA filters every 12 to 18 months, carbon filters every three to six months, wick filters every two months, and mineral absorption pads every two to three weeks.

How many years does an air filter last? ›

As a rule of thumb, most average drivers should be able to go one to two years before needing a new air filter. A word of warning: Any mechanic who recommends a new engine air filter every time you bring your vehicle in for an oil change (i.e., every 3,000-5,000 miles) is a red flag.

What happens if air filter is backwards? ›

By installing your filter backwards, air will have a harder time flowing through the filter and your air handler will have to work harder to make up for the loss of airflow. This could lead to higher utility bills and possibly damage your furnace or air conditioner.

Do higher quality air filters make a difference? ›

A high-quality air filter that costs a few more dollars can help keep the dust and other contaminants out of your lungs while also helping reduce allergens in the home. A cheap air filter may come with fewer pleats (sometimes called fold) which reduces the surface area to trap contaminants in the air.

Do more expensive air filters make a difference? ›

Yes, in general, the more expensive air filters are more effective, but a single person with no pets and allergies might not need as much filtration as a family of five with three pets and a child with asthma. Also, consider how long your air filter will last.

Do I need filters in my return vents? ›

In general, it is recommended to have an air filter in every return vent (as long as you choose the one of the right size and thickness). The filters will improve the air quality in your house and will protect the HVAC equipment from dust, pollen, pet dander, and hair.

What filter is better than HEPA? ›

ULPA filters trap more and smaller particulate matter than HEPA filters. ULPA filters are 99.999% effective at removing submicron particulate matter of 0.12-micron diameter or larger, while HEPA filters are 99.97% effective for eliminating particulate matter of 0.3-micron diameter or larger.

Is a carbon or HEPA filter better? ›

Which Is Better, Carbon or HEPA Filters? Both HEPA filters and carbon filters do things that each other can't. HEPA filters are better at removing bigger, physical particles like pollen, dust mites, mold, and other allergens. Carbon filters are better at removing odors, smoke, and other gaseous particles.

What is best filter to use? ›

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14 Aug 2022

Are 4 air filters better? ›

1” versus 4” Media Air Filters: Service Life

With more surface area to trap airborne contaminants, a 4” media air filter offers a longer service life than a 1” media air filter does. 4” filters last longer because they do not become clogged as quickly. Less filter changes means less money spent, and convenience.

Do thicker air filters restrict airflow? ›

A thicker filter (4-5 inches) has more surface area and therefore allows more room for air to pass through. Thick filters, due to their increased surface area, also have other benefits like: Higher dust-holding ability (meaning it can catch a lot without blocking airflow)

Does it matter what kind of air filter I use? ›

The short answer is, no, they're not all the same. In fact, there are many different types of air filters available and choosing the right one can make a real difference in the lifespan of your HVAC system. To understand the differences in the filters available, there's a couple of things you need to know.

What is that filter that everyone is using? ›

Surprisingly, the most popular filter on TikTok right now actually originated on Snapchat. TikTokkers have been using the "crying" Snapchat filter and posting it on their TikToks to make everyone look like they're at their emotional breaking point. The effect transforms even the most composed faces into hysterics.

What are the three types of air filters? ›

Several types of air filters are common in commercial HVAC systems:
  • Fiberglass filter. This throwaway air filter is the most common type. ...
  • Polyester and pleated filters. ...
  • High efficiency particulate arrestance (HEPA) filters. ...
  • Washable air filters.
7 Oct 2009

What MERV is too much? ›

Filters within a MERV rating of 17-20 are almost never necessary in a residential home. A MERV rating of 13-16 is considered hospital level air quality, so it is unlikely your home needs any more than that.

Can an air filter be too strong? ›

There's also a rise in pressure throughout the ventilation system that can create air leaks in the ducts and lead to issues with the AC such as frozen coils. An air filter that's too strong is all-around bad news for an air conditioner.

What is the most common air filter? ›

What is the most common size furnace filter? Currently, the most common size furnace filters are 10x20. But should your system need custom sized air filters, note that we offer custom sizing ranging from 8 x 24 x 1 to 25 x 30 x 1.

What is the difference between HEPA and HEPA type filters? ›

A True HEPA filtration device or filter is the only type of HEPA filter that truly conforms to the DOE standard for HEPA filtration, has the highest efficiency, and hits the 99.97% threshold. If the HEPA filter does not meet the DOE's standards for HEPA filtration, then it is not considered True HEPA.

How long do 4 inch HVAC filters last? ›

A three to four-inch filter can last for six to nine months. If you have a thick five to six-inch filter, it can last from nine to twelve months. By making sure that your filters are changed when they need to be, you can enjoy having a heating and cooling system that will work its best.

Does an expensive air filter make a difference? ›

More expensive air filters such as Pleated Residential filters will filter out dust mites, pollen, pet dander, mold, and even bacteria, which can be worth the extra money, especially for those with severe allergies.

Is there a big difference in home air filters? ›

The short answer is, no, they're not all the same. In fact, there are many different types of air filters available and choosing the right one can make a real difference in the lifespan of your HVAC system.

What MERV number do I need? ›

According to the ASHRAE, the best rating for residential HVAC systems is MERV 13. But before you upgrade your filter, make sure your specific system can accommodate that rating. A higher MERV rating often means lower airflow, which can cause the system to work harder—use more energy—to do its job.

Why are HEPA filters rarely used in homes? ›

Won't remove every particle: Unfortunately, HEPA filters will not remove pollutants from the air that are smaller than 0.3 microns, including viruses, some bacteria, and volatile organic compounds (VOCs). VOCs are household items like hairspray and ammonia that are too small for a HEPA filter to eliminate.

Which is better carbon filter or HEPA filter? ›

Which Is Better, Carbon or HEPA Filters? Both HEPA filters and carbon filters do things that each other can't. HEPA filters are better at removing bigger, physical particles like pollen, dust mites, mold, and other allergens. Carbon filters are better at removing odors, smoke, and other gaseous particles.

Is HEPA or HEPA 13 better? ›

A MERV 13 filter is a step in the right direction and captures more particles than a typical MERV 8 filter. However, it is not as good at capturing small virus sized particles like a HEPA can. A MERV 13 will trap less than 75% of air particles that are 0.3-1.0 micron in size (the coronavirus is 0.1 microns).


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