Different Types of Air Purifiers Explained
There’s a lot of information available regarding outdoor pollution, but did you know that out of many types of air purifiers there are 5 Most Common Air Purifiers on the Market?
Ongoing exposure to unclean air can lead to respiratory disorders, heart diseases, and cancer. An alarming statistic is that 3.8 million people die from indoor air pollution every year. Don’t become part of the statistics.
Indoor air pollution is caused by radon¹, tobacco smoke, mold, gasses from cleaning products, perfumes, and carbon monoxide. Another source is heating, ventilation, and air conditioning (HVAC) systems.
Studies have shown that these systems actually contribute to the issue because of poor installation or maintenance. This is a big problem, as 60% of US homes come pre-installed with at least one of these systems.
But where to start?
Through this article, you’ll discover:
Our editorial team has done extensive research and evaluation on this topic, to make sure that you get the best information about the different air purifiers.
How Air Purifiers Can Help
Air purifiers can help keep indoor air in tip-top shape. Clean air is vital for you and your family’s lungs, blood circulation, hearts, and other health systems. Air purifiers are also great for anyone struggling with allergies.
The Most Common Types of Air Purifiers
The most common types of air purifiers are:
- HEPA² Air Purifiers
- Activated Carbon or Adsorbent Air Purifiers
- UV (Ultraviolet) Air Purifiers
- Ionic Air Purifiers or Ionizers
- Ozone Air Purifiers
Air purifiers come in many shapes, sizes, and colors. Every air purifier uses a slightly different type of technology to cleanse the air.
Before choosing an air purifier for your home, it’s a good idea to understand how each one works.
Let’s look at the 5 most common types of air purifiers:
HEPA Air Purifiers
HEPA (high-efficiency particulate air) air purifiers use a type of filtration designed to strain out microscopic particles.
This technology has been around since World War II and remains a very popular method for purifying indoor air.
How Do HEPA Air Purifiers Work?
HEPA air purifiers work using a fan to draw polluted air into the device.
The air then passes through a filter (usually made of fiberglass). Airborne particles become trapped in a tangle of fibers.
The fibers then either intercept (when the particles stick to the fibers), get impacted (when the particles become embedded in the fibers), or get diffused (when the particles are bounced around by other airborne particles or gas molecules).
Diffusion is vital for trapping particles smaller than 0.1 μm (micrometers).
The air is pumped back into the room after the air passes through the filter. After that, the purifier draws in more polluted air to cleanse. The HEPA purifier drastically decreases the level of particulate matter.
The pros of HEPA air purifiers are that they are very efficient in preventing particle pollution with no harmful byproducts and can combine the filtration technology with other forms of purification for added benefits.
Some HEPA air purifiers come equipped with a UV pre-filter, which kills microbes removed by the HEPA filter, for example.
The cons of HEPA air purifiers are that they require a lot of maintenance, and the filters need to be replaced regularly. This leads to extra cost and effort.
HEPA filters can also create additional energy costs by restricting airflow through the unit, with stationary filters in central air conditioning or ventilation systems.
Lastly, HEPA air purifiers can’t completely remove odors or microbes.
Activated Carbon or Adsorbent Air Purifiers
Activated carbon purifiers work with a very absorbent type of activated carbon, either made in granular form or as a powdered block. Because of its porous nature, a little goes a long way to cover an extensive surface area.
And another thing
The activated carbon filter can absorb vast quantities of contaminants. This type of air purifier dates back to the early 1900s, when it was first sold and used to purify water and to take the color out of sugar.
How Do Activated Carbon Air Purifiers Work?
Activated carbon air purifiers work through a chemical reaction between the organic compounds and the activated carbon, which leads to the compounds sticking. This process is called adsorption.
The pros of activated carbon air purifiers are that they can be used alongside HEPA air purifiers, as well as that they are especially good at removing strong odors like smoke.
When used in conjunction with HEPA air purifiers, carbon air purifiers can trap and remove many pollutants, dust, and smoke.
Carbon air purifiers are also helpful to people with Multiple Chemical Sensitivity (MCS) or people suffering from asthma, because the air purifiers absorb formaldehyde³ (found in carpet, wood paneling, and furniture upholstery), making the air in the environment much more breathable.
The cons of activated carbon air purifiers are that they have a lower efficiency level in removing airborne particles and allergens, and there are also limitations in eliminating contaminants that are far away.
When contaminants are far away, they can’t be forced through the filter and can’t be completely eliminated.
For complete elimination, it’s best to consider high caliber room air purifiers, which offer outstanding particulate, odor, and chemical removal.
UV (Ultraviolet) Air Purifiers
UV (Ultraviolet) Air Purifiers protect the inside of our homes from the sun. In the same way that ultraviolet light from the sun harms the DNA and RNA within your skin cells, which increases your risk of developing skin cancer, we also need protection inside our houses.
How Do UV (Ultraviolet) Air Purifiers Work?
UV (Ultraviolet) air purifiers work with a UV lamp installation.
When microorganisms pass by, the UV rays radiate from the lamp, and microorganisms get demolished as cellular or genetic damage occurs.
This air purifier can turn molecules of oxygen and water found in your air into ozone and hydroxyl.
The process entails active molecules reacting with the air pollutants and destroying them into benign components like water and carbon dioxide.
The pros of UV air purifiers are that they are excellent tools in medical settings, especially as a method of antibacterial and antiviral disinfectant.
The reason is that they target airborne microorganisms and not nonliving particulates.
It’s also a good idea to use UV air purifiers as an addition to HEPA air purifiers to neutralise any microbes picked up by the HEPA filter.
The cons of UV air purifiers include that there’s a byproduct created when used, namely ozone, which can be very harmful. That’s why the effectiveness of UV purifiers is still being debated.
When air gets exposed to UV light, the same energy used to break the bonds of DNA in microorganisms can also split oxygen (O₂), which can reform into ozone (O₃).
Ozone is beneficial while high in the atmosphere, but is dangerous pollution inside our homes.
If the UV air purifiers only use “safe” wavelengths, we can avoid this from happening.
Also note that although UV technology can kill viruses and bacteria, it’s best used with a filter system ahead of the lamps. Without it, microorganisms can get shaded from the light by particulates.
Therefore, most air purifiers that work with UV technology start by filtering the air with HEPA and activated carbon and use the UV in the final stage of the filtration process.
Ionic Air Purifiers or Ionizers
Ionic air purifiers or ionizers use chemical injections to cleanse the air. An ion is basically a natural particle with either a positive or negative charge, and they get this charge by either gaining or losing an electron.
This type of air purifier was especially popular in the 1990s and early 2000s, offering a filterless alternative to HEPA air purifiers.
How Do Ionic Air Purifiers or Ionizers Work?
Ionic air purifiers or ionizers work with technology which magnetically attracts airborne particles, such as pollen and dust.
The particle then becomes too heavy to remain in air and drops and attaches itself to another solid item in the room, such as a window or a wall.
From there, it’s easy to wipe down these fallen particles.
The pros of ionic air purifiers or ionizers are that they are filterless and costs for replacements and upkeep are drastically less.
In addition, these types of air purifiers is much quieter compared to HEPA air purifiers, for example.
The cons of ionic air purifiers or ionizers are that they produce ozone and are less effective than other air purifiers.
These air purifiers don’t thoroughly cleanse the air but just mask it and don’t have the means to absorb and eliminate all the contaminants in the air.
As the particles fall onto surfaces, there is also a chance to re-circulate back in the air before being wiped away.
Ozone Air Purifiers
Ozone air purifiers produce the gas ozone (O₃), intentionally.
How Do Ozone Purifiers Work?
Ozone air purifiers work by using one of two methods: a corona discharge or UV light.
Both methods break apart oxygen molecules into two oxygen atoms. They then recombine into a new molecule of three oxygen atoms called ozone.
The pros of ozone air purifiers are that they can disinfect the air and kill microbes⁴. This is especially the case in industrial settings and settings without occupants.
Ozone levels must be high (5 to 10 times the public health limit) to eliminate biological contaminants, so that is why no human beings may be closeby.
The cons of ozone air purifiers are that they aren’t safe for public use and no federal government agency has approved these devices.
The main reason is that exposure to ozone may make asthma symptoms more prevalent. A high enough level of ozone can even scar the lungs permanently.
Ozone only masks the air and doesn’t cleanse it thoroughly, leaving particles in the air.
Last, ozone takes months to react with chemicals in the air and often leaves byproducts that could be even worse than the original chemicals.
Other Purifier Types to Consider
Although there are 5 main types of air purifiers, other options are available on the market. These include:
- Humidifier & Purifier Combos
- Electronic Air Purifiers
- UV Germicidal Irradiation (UVGI) Air Purifiers
- Photocatalytic Oxidation⁵ Air Purifiers
- Titanium Dioxide (TiO2) Filtration Air Purifiers
- Portable Air Purifiers or Room Air Purifiers
Humidifier & Air Purifier Combos
Humidifier & purifier combos can be a brilliant investment. There isn’t a lot of moisture in cold air, leading to a dry nose and cracked skin, especially in winter.
On the flip side
A humidifier causes increased humidity in your home and can become a breeding ground for molds and bacteria.
However, a humidifier and air purifier combo can eliminate these challenges and cleanse the air while holding on to the moisture.
Electronic Air Purifiers
Electronic air purifiers use technology that can charge particles in the air through a magnetic-like attraction.
The particles will then stick to plates on the machine or on to nearby surfaces.
These purifiers aren’t recommended, as they produce ozone, which is harmless, as discussed above.
UV Germicidal Irradiation (UVGI) Air Purifiers
UV germicidal irradiation (UVGI) air purifiers aren’t able to eliminate all viruses and bacteria, as some bacteria and mold are resistant to UV radiation.
To actually work exposure must last long enough, i.e. up to a few hours and not just a few seconds, typical of most UVGI air purifiers.
Photocatalytic Oxidation Air Purifiers
Photocatalytic oxidation air purifiers make use of ultraviolet radiation and a photocatalyst (such as titanium dioxide), to generate hydroxyl radicals that oxidize gaseous pollutants.
However, this reaction can produce harmful byproducts, such as nitrogen dioxide, carbon monoxide, ozone and formaldehyde.
Studies have reported these devices cannot effectively remove any of the compounds typically found in indoor air.
Titanium dioxide (TiO2) Filtration Air Purifiers
Titanium dioxide (TiO2) filtration air purifiers use the same chemical compound used as a pigment in most white paints.
However, it’s used completely differently for air purification.
Many hospital grade filtration systems use this system, which is great for cleansing the air from germs, smoke and unpleasant odors.
Portable Air Purifiers or Room Air Purifiers
Portable air purifiers or room air purifiers are suitable for cleaning a single room or an enclosed space.
These air purifiers are cost-effective, come in different sizes, are easy to carry around, and weigh less than 20 pounds.
They help clear harmful airborne particles, such as dander, pollen and smoke.
Is an Air Purifier the Same as a Filter?
No, an air purifier is not the same as a filter.
An air filter is built into your heating, ventilation, and air conditioning (HVAC) system.
An air purifier is a stand-alone appliance designed to purify the air, removing fumes and particles that a filter can’t remove.
What’s the Difference Between a Hepa Filter & an Air Purifier?
The Difference between a HEPA filter and an air purifier is that air purifiers are quiet, cost efficient, and don’t have filters.
HEPA filters are more effective at removing odors and removing the smallest particles of dust and pollutants.
All things considered, using either a HEPA filter or an air purifier will result in cleaner, fresher air.
What’s the Most Effective Air Purifier on the Market?
Is a Carbon or a HEPA Filter Better?
A carbon and a HEPA filter are equally good, as each one has a strength the other doesn’t.
HEPA filters are good at removing bigger particles such as dust mites, mold, pollen, and other allergens.
Carbon filters are good at removing gaseous particles, such as smoke and odors.
What’s Better Between a Hepa Filter or an Ionizer?
A HEPA air purifier is better than an ionizer, as it can remove pollutants from the air.
An ionizer doesn’t remove the contaminants but causes them to drop out of the air you breathe.
What’s the Difference Between a Hepa Filter & a Charcoal Filter?
The difference between a HEPA filter and a charcoal filter is that a HEPA filter’s fiber catches, intercepts and traps air particles that move through the filter, and there’s no trapping in Charcoal filters.
Carbon removes smoke, gas and foul odor and then the output is clean air.
Is an Ionizer & a Purifier the Same Thing?
No, an ionizer and a purifier aren’t the same thing. Ionizers and air purifiers cleanse the air using different technology.
Ionizers make particles heavy enough to fall to the ground, while air purifiers remove particles from circulation by trapping them.
As a result, particles must still be cleaned up with ionizers, and can therefore easily be reintroduced into the air.
Are Negative Ion Air Purifiers Safe?
Yes, most negative ion air purifiers (ionizers) are totally safe and do not pose health risks.
Although they release negative ions into the air to clean it, this is harmless. Ion air purifiers and ozone generators are often confused. The latter releases high levels of ozone that may have health risks.
There are many different types of air purifiers on the market today.
Each one has something about it that makes it stand out from the rest in terms of effectiveness at removing specific allergens like pollen, pet dander, or smoke particles from your home’s environment, while also neutralizing other things found inside, such as mold spores, bacteria, and viruses.
So make sure you do some research on the different types of air purifiers before making your purchase decision because not all systems are created equal.