Understanding Air Purifier Technology
By Becky Dotson
5 min read
If you’ve done any shopping for an air purifier, then you know there are plenty of brands, options and features available. Narrowing down the list to find the one that’s right for you can seem a little overwhelming. In this article, we help you understand the different types of air purifier technology so you can make the best choice for your needs.
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The purpose of an air purifier is to rid the air in your home of particles, contaminants and other irritants that can cause breathing troubles. So, it’s important to know the best performing air purifiers feature more than one filter technology. And you will discover an air purifier that uses HEPA-style filtration is the key to optimal results.
Types of Air Purifiers
HEPA Air Purifiers (recommended)
HEPA (high efficiency particulate air) technology was developed in the 1940’s during the Manhattan project. During World War II, scientists in the U.S. were working to develop nuclear weapons. In the process, they realized they needed to contain the spread of radioactive material in the air to protect themselves and because of this, developed HEPA filter technology.
The filters were eventually introduced for commercial use and made popular in medical cleanrooms – which are areas where pollutants are filtered out to create the cleanest space possible for medical and research purposes. HEPA is still the most reliable and effective filter technology in use.
Air purifiers equipped with a HEPA filter absorb up to 99.97% of all particles, like allergens, pollen, dust, dander, and other contaminants that are 0.3 microns and larger in size. A micron is one-millionth of a meter. Humans can’t see anything smaller than 10 microns with the naked eye, so 0.3 microns is very small. Harmful indoor air particles that cause allergy and asthma symptoms are measured to be about 0.3 microns or larger.
HEPA filters will capture pollen, dust, pet dander and many other airborne allergy and asthma triggers. But they won’t rid your home of bacteria, odors or smoke. That’s why you will find many air purifiers combining HEPA filter technology with another form of particle removal.
Pros: Most effective technology for air purifiers, and removes up to 99.97% of airborne particles
Cons: Filters must be replaced regularly
Electrostatic Air Purifiers (not recommended)
Some air purifiers use electrostatic technology which generates electric fields to trap airborne irritants. In very simple terms, electrostatic air purifiers work like magnets to pull dust, pollen and other particles out of the air. Electrostatic air purifiers give particles an electrical charge as they pass through the unit. Metal plates within the purifier are given the opposite charge – causing particles to stick to them, reducing the pollution in the air inside your home.
You don’t have to replace the filter of an electrostatic air purifier; you just rinse out the internal filtration system every few weeks to clean it. But electrostatic air purifiers generally don’t work as well at removing airborne contaminants as purifiers that work with filters, and often the smallest particles will stay stuck in the system decreasing the effectiveness of the overall unit.
Pros: No filter replacement needed
Cons: Not as effective in particle elimination as HEPA filters, and smaller contaminants can get trapped inside, making the unit less efficient
Ozone Generators (not recommended)
Ozone generator air purifiers are marketed as a way to eliminate strong odors and other airborne chemicals in your home. But they are not safe for you and your family to use. Ozone is a lung irritant and ozone generators can trigger asthma symptoms and attacks, and cause coughing, shortness of breath, chest pains and throat irritation. It can also make things much worse for someone already suffering from a respiratory disease.
In 2009, the state of California actually banned the sale of ozone generator air purifiers for home use because they’re so dangerous and unhealthy.
Pros: Can remove strong odors
Cons: Dangerous to use, and State of California has banned the sale of ozone generator air purifiers
Technologies That Complement HEPA Style Filtration
The best technology to pair with HEPA style filtration in air purifiers really depends on your need or concern. There are many different technologies that are used in air purifiers with HEPA filtration, such as activated carbon, pre-filters, and ultraviolet light. Choosing the best air purifier for you and your family can be time-consuming, but research and comparison shopping will pay off. During your search, be aware that the technology used is the most important factor you should consider.
Some air purifiers will incorporate a pre-filter as the first stage of filtration. Pre-filters are designed to catch the larger airborne particles, like hair or dust. A pre-filter doesn’t increase the effectiveness of the HEPA filter, it just extends the life of it. Pre-filters are generally easier to clean and maintain. Many of them can be vacuumed or washed.
Pros: Extends life of main filter, and can be cleaned and reused
Cons: Doesn’t increase air purifier effectiveness
Activated carbon is an absorbent filter that captures and neutralizes odors, smoke and some gases in the air. It can’t work alone, because it doesn’t trap airborne particles like HEPA filters do. Activated carbon filters have to be replaced more frequently because they become saturated faster.
Pros: Absorbs and neutralizes odors
Cons: Must be replaced more often
Ultraviolet C Light
Ultraviolet light (UVC) has been used for more than 100 years to disinfect hospitals, labs, kitchens and meat-processing plants. Now, it’s become a popular term and option in air purifier technology. It works in conjunction with other filters. Mold, mildew, viruses and bacteria will pass through the filters and then be neutralized and killed by the UVC light inside the purifier, before clean air is sent back out.
UVC light doesn’t come without its drawbacks. The Environmental Protection Agency (EPA) warns that UVC light used with HEPA filters can emit ozone – which is harmful to humans.
Pros: Can kill mold, mildew, viruses and bacteria
Cons: Can emit ozone
Bipolar Ionization is relatively new to the air purifier market, so the EPA says there isn’t much research yet of how effective it is. It works by generating positive and negative charged particles to help remove viruses out of the air.