Source: Global Direct Services

You Need an Air Purifier for Allergen, Virus, Odor and Gas Control.

Your choice of air purifier depends on what you are trying to achieve. For instance, if your main
goal is to clear the air of allergens, you should choose an air purifier which would remove the large particulates such as pollen with a pre-filter, but also smaller allergens, which would be particulates from 0.3 to 5 microns in size. An air purifier with a pre-filter can remove smaller allergens which include mold, bacteria, animal dander, fumes, and house dust mite allergens. A Hepa filter air purifier would trap particulates of this size and remove them from the air in your room. However, it is important to note that more than 90% of all particulates are 0.3 of a micron and smaller in size.

These are known as lung penetrating particles and are the ones most dangerous to your health.
Particulates of this smaller size, include viruses, some bacteria and germs, some house dust mite allergens, cat allergens, smoke, soot, fumes, and smog.

Since most standard Hepa filters (and there are some Hepa filters with enhanced filtration capabilities such as IQAir) would not be able to trap most of these smaller particles, there are also some machines that utilize ultraviolet light in combination or as a standard alone machine, where the rays will breakdown the DNA and RNA of the microorganism, and while not “killing”, they will sterilize those microorganisms, thus preventing them from being able to reproduce and grow. An excellent example of the this would be the Clarifier Air Defense System air purifier. A word of caution; all ultra violet machines are not equal and their quality and effectiveness varies enormously. The most important factor in determining the effectiveness of ultra violet light is whether the rays are strong enough in the first place, which is referred to as its dosage. Also, the rays need to expose the microorganism to the light for a long enough time in order for the DNA and the RNA to be altered.
Even if the ultra violet light is not completely effective, having one is better than nothing, because some of the micro organisms will be sterilized by the rays when they collide with the light or “bump around” with a side to side movement, so as not to move through the UV chamber too fast.

If you need an air purifier primarily for odor and gas control, you would want an air purifier that will first remove the majority of the particulates in a pre-filter and then have the gases and odors removed by the gas filter. Gas molecules are very small so they cannot be removed by even the finest Hepa filter. They are 0.001 and smaller. Therefore, they need to be physically removed by a substance that will trap them in their many micro pores. A good substance commonly used is activated carbon where it is super heated and steamed resulting in millions of tiny pores. Each one of these pores will be able to adsorb the gas molecules.

Global Direct Services provides access to free resources and information about Air Purifiers.