With this knowledge, you’ll be able to select the right purifier for your home or office. Let's start with the most popular filtration methods and how they work.
Air Purifiers: The Current Technology
HEPA FiltersOf all the various technologies used in air purifiers, HEPA filters are probably the most common and widespread. HEPA stands for High Efficiency Particulate Air, and it’s a filter that uses a variety of materials to achieve a large rate of airborne particle removal.
The defining factor for HEPA filters is not the specific material being used, but the level of efficiency in particle removal they can achieve. In order to be called a HEPA filter, it needs to remove 99.97% of all particles that have a size of .3 microns and larger. (A micron, or “micrometer,” is equal to one thousandth of a millimeter.)
Our EJ and ERIK filters perform better than the HEPA standard.
HEPA filters have been around for decades, and they are used in many different countries. While they have been revised and improved, the basic concept has been used since the 1940’s. In fact, it’s believed that the first HEPA filters were designed to remove radioactive elements during the Manhattan Project, the scientific mission that created the atomic bomb. After the war, HEPA filters found use in commercial settings and were especially popular in hospitals and clinics. Eventually, they became useful in homes and general businesses throughout the country.
HEPA filters are typically made of a mat of fibers, usually fiberglass. This media, however, does not lay flay, but is instead folded into multiple V shapes. These V shapes increase the surface space of the filter, thereby increasing overall performance.
The fiber mat found inside a HEPA filter allows air to pass through with relative ease. As the air passes through the extremely small gaps between the fibers, particles in the air, such as dust, mold spores, pet dander, and pollen, are trapped. While the technology is decades old, it is still the best for allergy sufferers.
One of the main benefits of using air cleaners with HEPA filter technology is that you know what you are getting, at least from a performance standpoint. In order to have the label of HEPA, a purifier has to meet specific standards set by the United States Department of Energy. So while the materials being used inside the HEPA filter can vary, the overall minimal performance will remain the same, giving consumers a consistent reference point.
HEPA filters are extremely useful for filtering out particles from the air, but they tend to be less effective when it comes to removing gases, chemicals and VOC's (volatile organic compounds). In this case, activated carbon, which we will turn to now, is often the ideal air filtration technology.
Activated CarbonMost people would not think of charcoal as a material that can be use for cleaning, but, when properly modified, this is actually one of the most important filtration materials that has ever been invented.
Activated carbon, also known as activated charcoal, has an extremely high surface space. This large surface space allows the material to capture an unprecedented level of airborne substances, including some of the most microscopic particles found in the air, such as chemicals and odors.
Using coal for cleaning and filtration goes back centuries. One of the early uses of the material was actually ingesting it for cleansing and purifying purposes. The material had been well established for it’s ability to capture pollutants, and scientist began experimenting with activated charcoal as a medication, the thought being that when someone consumed the material, it would sit in the stomach and absorb harmful chemicals, removing them when the charcoal is passed. There is documentation that activated carbon was actually used as an anti-poison medication as far back as the 1700s, and experiments with the material were performed in the early 1800s.
Activated carbon is often used for water filtration as well, and one of its most important uses is in air purification. When built into a filter, activated charcoal is able to capture some of the most microscopic particles found in the air. This includes particles that create odor, as well as the smells of cigarette smoke. It can also be used to remove harmful chemicals and VOCs.
To make activated carbon, manufacturers take a raw carbon material, such as wood, nutshells, coal and peat. They then remove all the organic matter in the material, leaving tiny spores throughout the carbon. Through various chemical and scientific processes, the material is then activated, which allows it to grab and hold the airborne contaminants.
When it is finally ready for use, a typical 50 grams of activated carbon will have the same surface space of roughly 10 football fields. This extremely high level of surface space, as well as the extremely small pores, allows the material to grab and hold microscopic particles, increasing the cleanliness of the air in a home or office.
UV LightUltraviolet light, typically called UV light, has been used to clean and sanitize water, air, and even hard surfaces. Unlike the air purification technologies we discussed above, UV light does not trap and hold particles, but instead disables organic matter, such as bacteria.
UV light is a short-wave form of light that can deactivate mold spores, bacteria, and viruses by altering DNA. Because all of these airborne particles are living organisms, they have DNA, just like you, me, your dog, and all other living beings. By disrupting or destroying the organism’s DNA, the particles are rendered useless.
While the uses of UV light, especially its effectiveness for bacteria and viral removal, still need to be studied, there is mounting evidence for this technology. A study published in Applied and Environmental Microbiology found that UV radiation could be an effective form or germicide to reduce fungal growth. After a complex study, the researchers found that “concentrations of fungi were significantly lower when UV lamps were in use,” although there were indications that not all forms of fungus that were studied were susceptible to the UV-C light.
UV air purifiers use the technology in a rather simple process. Basically, they pull in air using a fan then, depending on the purifier, pass the air through a pre-filter to remove many of the larger particles. The air then goes through an area, usually a self-contained chamber, that exposes the air to UV light. When the air meets the UV light, mold spores and other organic matter are harmed, disabled, or destroyed, reducing the chances that they can become a health hazard.
Ozone GeneratorsAnother technology that is used for cleaning and purifying air is ozone generation. An ozone generator is a tool that is advertised as an effective means to control air pollution, especially smoke and odors, but there is a large body of evidence that claims these machines should not be used by homeowners. First, let’s explore how these machines operate…
As the name implies, ozone generators create ozone, which is the combination of three oxygen molecules. These machines make ozone through a variety of means, including an electrical discharge or through the use of ultraviolet radiation. The result, however, is essentially the same: the release of ozone.
Ozone is a highly reactive chemical. Made of three oxygen molecules, ozone is able to interact with other substances because the third oxygen molecule can easily detach and reattach itself to other substances, altering the molecular chemistry of the new substance. This is the process that makes it useful for the removal of odors. When ozone is released, it can attach itself to the molecules that create odor and destroy them, thereby destroying the odor itself. The same process helps ozone destroy gases, making it an effective tool for air purifying; unfortunately, it’s also a dangerous tool.
This means that ozone can interact with the cells in our body and, when inhaled, the cells in our windpipes and lungs. At low amounts, ozone can cause chest pain, coughing, and throat irritation, and it can worsen chronic diseases.
While effective, most experts do not recommend using an ozone generator for your home. This is because of the significant health concerns associated with releasing ozone directly into your living space. If you have serious odor issues in your home, such as rampant cigarette smoke, or significant mold growth, you may hire an expert to come in and use an ozone generator.
Ionizing Purifiers, aka Electrostatic PurifiersOne of the most unique technologies in air purification, ionizing air purifiers, sometimes called electrostatic air purifiers, use an electric charge to trap particles against a component inside the air purifier.
The purifiers create an electric charge that negatively charges particles in the air. The negative ions are then exposed to a positively charged surface, which holds them tight, similar to a magnetic pull. The pull traps the particles, removing them from the air.
Through ionization, ozone is formed and released into the surrounding air, which is one of the most significant drawbacks of ionizers. When selecting these machines, you need to be extremely careful to avoid any appliances that may release ozone. For this reason, ionizers are generally used for industrial purposes, and are rarely put to use in the home.
Adsorbent MaterialsAdsorbent air purifiers (yes, adsorbent, not absorbent) are effective machines for removing chemicals and extremely small particles from the air, including VOCs. These purifiers use a material called an adsorbent, which acts like a sponge, collecting odors and chemicals from the air. Adsorption is the process of a substance sticking to another substance.
Essentially, the chemicals inside the adsorbent air purifier grabs the particles from the air and traps them, keeping them from becoming air pollution. The carbon in the EJ120 and ERIK air purifiers use coconut shell based activated carbon.
A Look to the FutureAir purifier technology is always in the process of development, and while the current technology is extremely effective, you can expect even greater advancements in the future. Which ones become the most popular has yet to be seen, but these are a few of the innovations you might see in your home over the next few decades…
One innovation that could become popular is wearable air purifiers. With increasing advancements in the efficiency of air purification, manufacturers will likely start developing products that users can wear on their heads to purify the air they breath. In a way, it would be a type of breathing mask, but it would be much smaller, looking more like a thin headset as opposed to a large gas mask.
The visual appearance of air purifiers will likely change. With new advancements, manufacturers will be able to squeeze air purifiers into smaller shapes and unique sizes, perhaps giving the machines a decorative look, which could increase their adoption rate. Under the same principle, you may see air purifiers built into typical household items. For example, someone’s kitchen table could also function as an air purifier.
In the future, we may see a variety of new materials being implemented in air purifiers, most of which will be used in the filtration of air. Wool, for example, could become an increasingly useful material for air purifiers. Filters made from wool could be an effective way to remove dust, allergens, and other particles from the air, although more studies and developments are required to fully understand how useful wool can be, and what types of air pollution it might best remove. Nanofibers could also become a popular material for air filtration. Various organizations are developing extremely-fine nanofibers that could increase the filtration potential of air purifiers all across the globe.
From massive air purifiers for colossal buildings, to extremely small purifiers that are barely noticeable, air purifier technology is changing rapidly. Look for new developments to help you maintain clean air in your home with less pollution and dust.