5 Air Filters and Why You Need Them

Like the mythical bogeymen, the irritants in our air are mostly unseen, but their damaging effect starts from our nasal passageways, seeps into our lungs and permeates right into our most crucial bodily functioning. Unlike nameless goblins, however, these irritants have names– dust mites, pollen, airborne bacteria, tobacco smoke and formaldehyde, to name a few. In this article, we will understand the physical composition of these allergen and toxic particles, and explain which types of air filters are most equipped to trap or eliminate them.

Know Your Airborne Irritant

The biggest factor in trapping airborne irritants is knowing their size. Certain filters are only equipped to trap bigger particles, while specialized filters can trap microscopic particles. However, there are still many toxic substances that aren’t solid particles at all, but are gases. For example, aerosol pesticides. These need an entirely alternate method of filtration to prevent them from invading your living spaces. That’s why a comprehensive air purifier needs an arsenal of filtration systems.

Pre-Filters: The First Line of Defense

Pre-filters trap larger particles, and their purpose is to increase the lifespan of finer filters like the HEPA. They are perfect for capturing pet hair, large dust particles, and even pieces of dead skin. Because pre-filters act as the first line of defense against air pollutants, they typically need to be replaced more often than HPEA or carbon filters.

HEPA Filters: The Power Trapper

High-Efficiency Particulate Air (HEPA) filters are composed of a mat of randomly arranged fibers. The classification of a True HEPA filter is one that can remove 99.97 percent of particles that are at least 0.3 micrometers large from the air. To give you a concrete understanding of what these figures imply, consider that a human hair has a diameter of 30 microns while a pollen particle is as small as 10 microns!

The ability of True HEPA filters to remove pollen, hair, dust, mold spores, and other air pollutants makes them great for allergy relief, asthma support, and all-around healthier living. True HEPA filters have already established their place in hospitals, food manufacturing facilities, or the microelectronics industry, and they can be tremendously useful at home.

That said, even True HEPA filters do not filter out gasses and odor molecules, which is why they are often combined with activated carbon filters to provide filtration of volatile organic compounds (VOCs), chemical vapors, cigarette smoke, and household odors.

Activated Carbon Filters: The Odor Destroyer

Carbon (or charcoal) filters excel at odor and chemical removal – much more so than many other filter including the HEPA. Charcoal is an extremely porous element – it has a large surface area with many nooks and crannies. Activated carbon has been chemically treated to increase the surface area and to cause a bonding reaction with the pollutants that pass through it. The pollutants stick inside the nooks and crannies and are, quite literally, captured. Carbon filters adsorb chemicals and gases from the air, including volatile organic compounds (VOCs), formaldehyde, paint fumes, tobacco smoke, or simply unpleasant odors such as burnt food.

Cold Catalyst Filters: The Atom Attacker

The newest breakthrough in air filters are those that target impurities on the Nano level. As its name implies, a cold catalyst filter causes a catalyst – or a chain reaction – within the atomic composition of these harmful gasses or microscopic particles. Using an ultra violet light, the cold catalyst filter causes the electrons in the atoms to break apart their chemical bonds—essentially decomposing them. This process completely transforms the behavior and composition of these polluting particles and renders them harmless.

Ionic Filters

A basic law of physics is that opposites attract. Ionizers emit a negative charge to particles, making them electrically-static. These negatively charged particles stick to the positively-charged filter plate, collecting them in one convenient location rather than floating in your atmosphere. Ionic filters are effective against dust, smoke particles, tiny contaminants as small as 0.1 microns, and are generally effective at deodorizing your air.


Which Air Filters do I Need?
Large Particles Small Particles Chemicals & Odors Microorganisms
Pre-Filter X
HEPA Filter X X X
Active Carbon Filter X
UV Filter X
Ionic Filter X X X


A quality home air purifier should be equipped with a range of filters to trap the spectrum of contaminants in your air, from dust mites to diisodecyl phthalate (an odorless compound found in plastics). Check out our Bluemyst air purifier. Its detailed five stage filtration gives you deeply cleansed and breathable air.