Searching for an air purifier can be a very confusing task.  Air purifiers come in many different sizes and shapes, contain different technology which may or may not work, and in some cases, may cause harm.  Some “filter” the air and some actually “clean” the air by destroying the contaminants.  Let’s take a look at the options:

Ozone Generators

An Ozone Generator uses ozone as its primary source of purification.  Ozone is an unstable oxygen molecule (03) that attaches to (oxidizes) any other molecule it contacts.  If it comes in contact with an iron molecule, for example, it will create iron oxide - which is rust.  These purifiers propel the ozone with a fan, enabling the ozone to oxidize molecules it contacts.  The process works very well for removing odors, killing mold and mildew; however, it can be extremely dangerous to small animals and human beings.  An overexposure to ozone can bring on asthma symptoms and a high level of ozone can scar your lungs or even kill you.

Electronic Purifiers

Electronic air cleaners employ an electrical field to trap particles. Much like mechanical filters, electronic air cleaners can be installed as central filtration systems or purchased as portable units with a fan.  Electrostatic precipitators, the most common type of electronic air cleaners, use two stages the first stage draws air in with an electrode or wire and the second stage collects the particulates on plates.

The simplest form of the electronic air cleaner is the negative ion generator, which creates static charges to remove airborne particles. All particulates in a room become attracted to surfaces, and deposit themselves on walls, floors, table tops, curtains - even occupants!

Keep in mind that using this kind of air filtering system will cause more soiling of your furniture and walls and require consistent vacuuming and cleaning routines so that the material is removed.  More advanced units are theoretically designed to reduce soiling in a room. These filtration systems create negative ions within a space though which air flows, and then use a fan to pull back the charge particles into the cleaner.

Electronic air cleaners can produce ozone either as a byproduct or intentionally, as is the case with ozone generators. This has been a concerno recently for air quality experts since ozone can be a potent lung irritant and exposure to elevated levels can be dangerous for people with asthma and other chronic lung diseases.

The benefits of electronic air cleaners are that, unlike HEPA filters, they generally have a low energy cost. The airflow through the unit is constant, and helping lengthen the time between replacement of filters. However, the units can become less efficient with use and require frequent cleaning.

Electronic purifiers cover smaller areas such as bedrooms and small living quarters; however an increased air flow reduces the unit’s effectiveness in removing airborne particles.  Electronic units remove some dust and pet dander but are not recommended for removal of chemicals, smoke, molds, bacteria and certain smaller pollen particles.

Filter Purifiers

Air purifiers that draw air to trap particles are known as “mechanical filter” purifiers.  They use at least one of the following filter types:

HEPA Purifiers

To qualify as a true HEPA, a filtering system must allow no more than 3 particles out of 10,000 to penetrate the filter. HEPA filters can be found on standard central filtration systems and on HEPA portable units.

The filter of a HEPA air purifier is made of tiny glass fibers that produce a consistency similar to blotter paper. This means that a HEPA purifier is like a tremendous high-pressure system, with air forced through the filtration system under great pressure.  This makes HEPA filters an expensive proposition in a residence. With powerful fans and engine horsepower, HEPA in a home can be an enormous and consistent drain on electricity.

However, don't make the mistake of comparing horsepower or wattage of brands to determine performance ratings. When it comes to HEPA effectiveness, look into air displacement effectiveness. Air displacement describes the amount of air moved, measured in cubic feet per minute (CFM). Look for purifiers with high air-displacement HEPA filters for the best recovery of smaller particles such as bacteria, pharmaceutical dust, lead paint or asbestos fibers. A small room purifier may offer as little as 80 CFM displacement, while larger industry models can range on average from 500-80,000 CFM.

The problem with HEPA Purifiers is that they can not remove odors, chemicals, or gases.  Since which are molecular level substances. The 0.3-micron holes are large compared to gas molecules or viruses.  Since air must pass through the filter to be effective, it can be difficult to clean a large room with a HEPA Filter.  Long term cost of a HEPA unit can be high due to the amount of energy required to pull the air through the filter as well as the replacement costs of the filters.

Ionizers

Home air ionizers replenish a room's supply of negative ions, which are essential for clean and pure air. While a home normally possesses less than 100 negative ions per cubic centimeter, healthy outdoor air has up to 4,000. In fact, the highest levels of negative ions can be found in the pristine areas of the world - such as the Himalayas, the Alps and Antarctica!

Most floating contaminants and allergens are positively charged.  Home air ionizers improve air quality by removing dust, odors and other common pollutants through the use of negatively charged ions (an ion is any atom that has a positive or negative charge). Negative ions generated by the air cleaner literally attach themselves to microscopic particles, which then become too heavy to remain airborne and fall to the ground.

However, the problem is that these particles also stick to the walls, the ceiling, furniture or anything else they contact.  Because the particles that the negative ions attract are never destroyed or contained in a filter, they remain in the room and could become loose and able to recirculate.

American Air Scrubber technology is patent pending.