It is important for us to know how things we use operate.  This is not only for the sole sake of knowledge, but being informed helps us make better decisions that make things better for us in the long run.  Since air purifiers can be expensive, you want your purchase to go as far as it can, just like with a car.

The basic premise of an air purifier is that it sucks in air, removes all or most of the contaminants, and then releases it back in to your home in a better state.  While that sounds simple, the actual process and the engineering of the device is more complex, yet still fairly easy to understand.

Air purifiers of the past picked up much less than what the quality ones of today do.  In addition to pollen, dust, smoke, and other allergens, modern air purifiers can take out bacteria and viruses as well.  The vast amount of contaminants removed from the air is extremely beneficial for those with breathing problems, and advantages are available for everyone, no matter what kind of health they have.

The most simple form of purification is a basic filter, which lets through air but traps particles that are bigger than a certain size.  For example, HEPA filters can trap nearly all particles down to a hundredth of a micrometer.  Virtually all dust and common allergens fit this profile, so HEPA filters work well for the majority of the population.  Also, they use less energy than other filters and release no contaminants of their own.

A more advanced filtration technique is that of ultraviolet germicidal irradiation.  With this technique, UV lights are placed discreetly inside the device, and they blast air coming past it with the rays.  These bursts of short-wavelength light sterilize the air by decomposing the microorganisms.

The type of purification usually found advertised the most is that of ionic purification (like the Ionic Breeze).  The machine generations gas ions, which attach to contaminants in the air, and these negative ions (anions) are filtered out.

There are several other types of interesting filtration methods, such as photocatalytic oxidation, which catalyzes the oxidation of bacteria through light (photo), in a similar manner to ultraviolet germicidal irradiation.  Being that there are so many different types of filters out there, you need to find which one would work best for your home, as certain methods have advantages over others.

Unlike man, not all air purifiers are created equal.  In an ideal world, every product that we bought would work as advertised and with the greatest effectiveness.  However, some businesses prefer to cut back on the quality of their products in order to make more money, and to compensate for the inferior specs of their devices, they simply invent clever marketing tactics to trick people in to buying what they are selling.  The case is no different when it comes to air purifiers, and there have been some controversial cases involving faulty air purifiers that have caused quite a stir within this industry.

The most controversial case regarding air purifiers was the turbulence between Consumer Reports and Sharper Image regarding the Ionic Breeze, which had several incarnations.  Consumer Reports and another similar firm tested the Ionic Breeze and found that it hardly removed any contaminants from the air at all.  If that were not bad enough, it was also found that the machine was releasing dangerous amounts of ozone, so not only was the machine not helping, but it was hurting!  People were paying hundreds of dollars to hurt themselves, and not too many people were happy about hearing such news.  Due to this and other factors, Sharper Image was driven in to bankruptcy and almost completely out of business, but it still exists today and provides several quality products.

One should not be deterred from purchasing an air purifier just because of some negative publicity in the past.  The fact remains that good air purifiers are effective and can improve the health for those who use them.  You can find an optimal air purifier by reading customer reviews of the products first, and by looking to see if any scientific testing has been done on them.  Using these resources together, you can make an informed purchasing decision, and end up with a high quality personal air purifier that will clean the air in your home for years to come.