As humanity enters the 21^st century, and embraces new and innovative technologies, we do not always stop to think about the potential cost of modern conveniences. Our lifestyle brings many disadvantages, and one of these environmental costs is an increase in the level of pollutants in the atmosphere, both inside and outside our homes. Pollutants, such as vehicle exhaust gas, tobacco smoke and animal hair, are the underlying reason for an increase in the number of people suffering from allergies and asthma.

Central heating and air conditioning make life bearable, and many families would be lost without these modern technologies. This comfort does carry a cost and, as people seal themselves indoors, atmospheric pollutants circulate, aggravating allergies and contributing to the increase in cases of respitory illness. Recent studies, performed by the EPA, showed that air inside buildings contains 2 to 5 times the pollutant load of exterior air, a frightening statistic.

One way to fight this pollution, and improve health, is to invest in an air purifier.  However, there are many different types, and each carries its own unique advantages and disadvantages. Before trying to select the best air purifier for your home, it is wise to seek medical advice and ensure that you are aware of the pollutants responsible for your particular allergy.

The HEPA air purifier is a readily available air purifier, and is the best option for general use. HEPA filters use a fabric filter to extract 99% of the larger particles from the atmosphere, vastly improving air quality. HEPA air purifiers come in many sizes, from the small tabletop units used to clear a small room, to larger models used to purify an entire house or workplace.

The Advantages of HEPA Air Purifiers

• Small HEPA air purifiers are easy to find, and are available in most major electrical retailers.
• HEPA air purifiers are the best solution for filtering out pollen, dust and animal hair.
• The HEPA purifier removes particles efficiently and permanently, and is a great help to asthma sufferers.

The Disadvantages of HEPA air purifiers

• Cheaper HEPA air purifiers are obtrusive, ugly and noisy, and good quality, larger models are often expensive.
• HEPA air purifiers do have their limits, and cannot filter particles smaller than 0.3 microns. They are not the answer for every particular situation.
• HEPA purifiers do not remove odors, bacteria or chemical pollutants
• The fabric filter eventually wears out and needs periodic replacement.

Germicidal air purifiers are the perfect solution for removing biological pollutants from the atmosphere, including bacteria and mold spores. The vast majority of germicidal air purifiers incorporate a HEPA filter, to remove large particles and bacteria. A UV lamp then sterilizes and destroys smaller organisms, ensuring that germicidal air purifiers remove up to 80% of the biological pollutants from the atmosphere.

The Advantages of Germicidal Air Purifiers

• The strong UV light kills bacteria, mold spores and viruses, so germicidal air purifiers are the best solution for air-conditioned buildings, which recycle stale, germ-laden air and spread disease.
• The inbuilt HEPA filter removes dust and pollen from the atmosphere, giving the germicidal air purifier the same advantages as the HEPA air purifier.

The Disadvantages of Germicidal Air Purifiers

• The units are expensive when compared to HEPA filters. They also possess all the disadvantages of the HEPA air purifier.
• They are ineffective at removing odors and gaseous contaminants, such as paint fumes.

Ionic air purifiers are one of the filterless air purifier types, unobtrusively and efficiently removing allergens from the atmosphere. Ionic air purifiers operate on the principle that most airborne contaminants are positively charged. Natural air contains an abundance of negatively charged ions, which are attracted to contaminants, and cause them to form heavy clumps that fall to the ground. Inside buildings, there are few negative ions, and ionic air purifiers seek to re-establish the balance, causing pollutants to aggregate and fall.

The Advantages of Ionic Air Purifiers

• The negative ions remove even small particles from the air.
• Ionic air purifiers are effective at removing bacteria, viruses and fungal spores.
• Ionic air purifiers are extremely quiet and unobtrusive.

The Disadvantages of Ionic Air Purifiers

• Ionic air purifiers have a very limited range, so an individual unit is required in every room.
• Ionic purifiers do not kill germs or fungi; merely remove them from the air. If they fall onto a kitchen worktop, for example, there is still a chance of spreading disease.
• Ionic air purifiers do not remove odors or fumes from the atmosphere.

The Ozone Air Purifier generates ozone, a powerful gas that removes pollutants and foul odors from the atmosphere. As a word of warning, high concentrations of ozone can be extremely toxic, so ozone air purifiers should be used with caution, in unoccupied or well-ventilated rooms. They are often used to remove mold spores from old buildings.

The Advantages of Ozone Air Purifiers

• Ozone air purifiers are the best choice for removing foul odors from the atmospheres.
• Ozone air purifiers are adept at removing certain chemicals and bacteria from the air.

The Disadvantages of Ozone Air Purifiers

• Ozone is not very efficient at removing particulate allergens, and is limited in the types of bacteria and chemicals that it can neutralize.
• Ozone is a toxic substance, and you are strongly advised to seek a professional opinion before installing an ozone air purifier.

This carbon filter air purifier uses an activated charcoal filter to remove a wide range of contaminants. The activated carbon particles contain microscopic pores, which trap gases and micro-particles, in the same way as the familiar gas-mask filter. Most carbon filter air purifiers pre-filter the air with a HEPA filter, to remove larger particles that will quickly clog the micro-pores.

The Advantages of Carbon Filter Air Purifiers

• Carbon filter air purifiers fitted incorporating HEPA filters are extremely efficient, and remove a wide range of pollutants from the atmosphere.
• Carbon filter air purifiers are the best option for alleviating most allergies.

The Disadvantages of Carbon Filter Air Purifiers

• Carbon filter air purifiers are not perfect, and some viruses and small mold spores can persist in the atmosphere.
• The HEPA and carbon filters need to be replaced regularly, adding to the cost.
• Carbon filter air purifiers are one of the most expensive types to buy, and the HEPA incorporated purifiers are often noisy.

Summary - Finding the Best Air Purifier for your Needs

Before investing in an air purifier, you need to be fully aware of exactly which allergens and pollutants you need to filter from the air. For example, a person with asthma may need to remove pollen and animal dander from the air, whilst a business might want to remove germ-causing microbes from the office.

All of the air purifiers have their own specific advantages and disadvantages, so many manufacturers offer hybrid air purifiers that incorporate two or more of the above methods. Whilst this increases efficiency, it does push up the price, yet another factor in choosing the best air purifier for the job.