In order to find an air purifier that will work for you, first you have to know what pollutants are in your air.  There are the obvious indoor offenders like dust, dust mites and dander—but what about the fumes from cleaning products or the effects of airborne bacteria?  These common, yet usually overlooked air contaminants have just as much impact on your health as airborne allergens—and many times are a contributing factor to allergic reactions and asthma attacks.

Microbes

These are the germs, viruses, bacteria and mold spores that can cause illness or infection in individuals with allergies or asthma, because their immune systems are constantly expending themselves on allergens.  Yet, even a completely healthy individual is susceptible to viruses like flu and streptococcus—by using the correct air purifier, these can be eliminated from the air.

Odors

Smells can have an effect on your overall well-being—many people experience headaches because of certain odors from smoking, cooking, pets, etc.

Gases and Chemical Fumes

These are also called “volatile organic compounds” (VOC’s) that are found in everyday cleaners, aerosol sprays, cigarette smoke, adhesives used to make furniture and cabinetry, nail products, etc.

Particulates

Allergens are usually large enough to be considered particles, but still are small enough to thousands one the period at the end of this sentence.  Another common source of particles is the visible cloud of smoke from cigarettes, cigars and pipes.

There are several different technologies utilized by air cleaners and air purifiers

HEPA air filters

High efficiency particulate air filters remove at least 99.97% of particles 0.3 micrometers in diameter.  The filters are comprised of randomly arranged fibers that collect particles in air that passes through it.  Air cleaners with HEPA filters usually will need to have the filter replaced every year or so.  This type of air cleaner is very effective for those with allergies and asthma (and is indorsed by the American Academy of Allergy Asthma and Immunology) and are safe for individuals suffering from different lung conditions.  HEPA is also able to remove the visible clouds of smoke from the air, though it does not address the fumes or odors (usually HEPA is part of a two step technology to remove smoke).

Ozone Makers

Ozone is a reactive oxidant that is able to neutralize different chemicals and bacteria in the air and is very effective at eliminating odors.  These machines rely on ozone to clean the air.  It is often suggested to keep these sorts of machines running on their lowest setting because too much ozone can irritate delicate lungs—if needed, you can turn up an ozone making air purifier to remove strong odors or heavy smoke smells while people are out of the house.  These machine sare not recommended for inviduals with asthma, COPD or any other condition that effects the lungs.

Carbon Air Purifiers

Because of the porous nature of carbon, it is one of the most effective methods of capturing fumes and chemicals.  Impurities are passed through pores in the carbon, where they are adsorbed and actually bond with the carbon.  Most carbon filters, like Dynamic, will also have a HEPA filter, giving a complete and highly effective air cleaning system.  At some point the carbon will have adsorbed enough to become saturated and needs to be replaced.  Depending on the amount of carbon used, the life-span of the filter will vary.  Dynamic filters typically need to be replaced every 3 months on average—when used to remove smoke from an office or other room, it is recommended that they be changed every 1-2 months, depending on the heaviness of pollution.  (Dynamic filters also use ionization—described below– to give maximum results.)

Ionizers

The filters do not have a cloth filter, but create a positive or negative charge to “ionize” contaminants in the air so that they will be attracted to collection grids.  This charge also causes individual particles to cling to one another, forming larger particles that are easily caught on a second pass through the machine if they were too small to be collected on the first.  Some ionizers do not have collection plates, but create a charge so that smaller particles will attach to each other until they are large enough to fall out of the air altogether.

Ultraviolet Light

Ultraviolet (UV) light sterilizes the air, eliminating microorganisms like bacteria, viruses, germs and mold.  After passing through this type of filter and being exposed to UV light, these microbes can no longer reproduce or grow.  It is important that the right amount of UV be used, and that each contaminate has a sufficient amount of UV exposure time (a fan that pushes air through to quickly will not be the most efficient at sterilizing the air).

Hydroxyl Radicals

These cleansing agents naturally occur in the Earth’s atmosphere are capable of neutralizing mold, bacteria and viruses very effectively.  When oxygen atoms pull a hydrogen atom from water vapor, this radical is produced.  Hydroxyl radicals are 1,000,000 times more potent at destroying airborne pollutants that ozone.  When used in conjunction with ionizers or ultra violet, it is able to neutralize all categories of indoor pollution except particulate (unless it also has a filter).  Biozone makes several different models of air purifiers using this technology.

So, which air cleaner should you choose?

For Allergies to Dust, Dust Mites, Animal Dander, Pollen and Cockroach:

You will need a filter such as a HEPA to remove the offensive particles from the air.  Using ozone makers or ionizers alone will not remove allergens, and the ozone can irritate the delicate lungs of asthmatics.  For example: Dynamic Air Cleaner 1" Panel

For Smoke Removal:

You will need a two-step approach to solve this problem, because smoke consists of two forms of air pollutants– particles (visible smoke) and gases (airborne chemicals and odor).  A HEPA or carbon filter will remove the particles from the air– but to eliminate the heavy scent, you may want to also use a hydroxl radical cleaner or appropriately-size UV or ozone air purifier.  For example: Dynamic Air Cleaner CT500 or Pollution Research SRS800 Smoke Eater.

For Mold, Musty Smells and Mold Allergies:

Either a UV or a hydroxl radical air purifier will neutralize the odors and sterilize spores.  If the spores are no longer active, they cannot sprout into new mold or irritate the lungs.  Over a short period of time, these air purifiers will help eliminate mold inside your house.  For example: Air Oasis 1000 Air Purifier or Biozone 1000 Air Purifier.

For Asthma or Other Lung Conditions (in children and adults):

A HEPA, Carbon or even an Ionizing air filter will give the best results without any additional lung irritation.  For example: Dynamic Air Cleaner CT100 or  the Dynamic CT500

One last tip for purchasing an air cleaner: never fall for a one-size-fits-all air cleaner!  The machine you purchase should have enough power to match the square footage of the room(s) in which it will be used.  An air puifier may work wonderfully, but if it's too small to handle the amount of contaminated air, you may not see any results.