Ionic Air Purifier Technologies – Scientific Fact or Science Fiction?

Initiation

Ionic air purifiers hold the promise of clean air, purified of all known harmful contaminants that threaten our health. These harmful contaminants are not noticeable to our naked eyes. Invisible ions battling invisible contaminants appears to make perfect sense. Intuitively, the logic appeals to me. But these days, finding a simple and quick solution is rare. Googling the theme unearths a ton of controversy. Observably, I must resist the urge to go by intuition and grab the first ionic air cleanser that I lay hands on. Product safety must take precedence over effectiveness in choosing an ionic air cleanser.

The recent China melamine saga that killed infants also serves as a reminder to us that in buying into any technology or any product, all claims by manufacturers and distributors must be examined to the fullest extent that our resources permit. Where the reactive agent is invisible, it becomes even more vital to focus on it. Investigating ionic air cleanser technologies falls within this ambit as the reactive agents are invisible ions.

In this condition, I am laying out the roadmap as I look into the existing ionic air cleanser technologies in the global marketplace. My back-to-basics approach is an attempt, as a amateur, to know the knowledge behind the technology. A dominant contemporary trend appears to be the foundation of an invisible but potent defence shield against above ground molecular contaminants. The predominant above ground threat being monitored by scientists the world over is the avian flu virus.

Types of Ionic Air Cleanser Technologies

Broadly speaking, air refining technologies can be deployed in either passive or active modes. Passive typically means that impure air is drawn into the air cleanser for the reactive agents to work on before re-emerging as cleaned air into the background. In active mode, the reactive agents are pushed into the background with the impure air. Fascinatingly, marketeers betray their lack of confidence in their own ionic air cleanser technologies by combining both passive and active modes.

In the global market today, ionic air cleanser technologies contain the following categories:

(A) Ion generator – clear and negative ions
(B) Ion generator – negative ions only
(C) Photocatalytic Oxidation (POC)
(D) Electrostatic filter
(E) Combos

Ion Generator – Clear and Negative Ions

This amalgamation of clear and negative ions appears to show the most promise for the future of ionic air cleanser technology. Pioneered by the Japanese corporate giant, Sharp Corporation, they are known as plasmacluster ions.

Sharp Corporation’s marketing efforts focus on the skill of plasmacluster ions to surround and cling on to harmful above ground bacteria and viruses. When this happens, hydroxyl is bent. Hydroxyl, also known as nature’s detergent, is a commanding reactive species that plucks out hydrogen molecules from the organic structure of these above ground particulates so destroying them. The by-products of this chemical result, mainly water, are undisruptive.

A differential ion generator is used in this technology, comprising a clear and a negative ion generator which can be powered in every second cycles to hegemony the type of ions generated.

Advocates of the clear and negative ions amalgamation claim that a balance of both these ion types is to be found in places like waterfalls and pristine forests, i.e. this is the actual state in nature. Proponents of negative ions believe that negative ions dominate the background in these untreated habitats and even insist that clear ions are harmful. Thus far, I have not found any independent scientific studies to help the opposing claims of the two technologies.

Ion Generator – Negative Ions

The habitual ionic air cleanser produces only negative ions. Apparently, negative ions technology dominates the ionic air cleanser market at the moment but Sharp’s plamascluster technology is increasingly proving to be a serious alternative.

It is claimed that nearly all harmful above ground particulates like dust, smoke and bacteria etc have a clear charge. Negatively charged ions are naturally attracted to these particulates until they sink to the ground by sheer weight. Thereafter, simple vacuuming removes these impurities. Detractors of negative ion technology believe that the “overweight” particulates on the ground are not ruined and that the mere act of on foot on them re-contaminates the air.

There appears to be several methods of producing negative ions. This has significance as the various methods result in different by-products, some of which are harmful. These methods contain:

(1) Water method – this employs what is known as the waterfall or Lenard Effect. Onto a metal plate that is electrically-charged, water droplets are splashed. The charge splits the water droplets resulting in the production of a large number of negative ions. No harmful by-products result from using the water method to yield ions.

(2) Electron radiation method – this is based on a single negative discharge electrode needle. Negatively-charged electrons are bent by the millions when a high voltage pulse is applied to the electrode. This process does not generate any ozone. It is claimed that this is since a “less vital” energy pulse is applied.

(3) Corona discharge method – this is based on a dual electrode model, a sharp metal electrode and a flat electrode. A very high voltage is applied between the two electrodes. The movement of electrons between the electrodes ionises the air in that same space. A criticism of this method is the production of harmful by-products like ozone and nitride oxide.

Photocatalytic Oxidation (POC)

This technology is commonly applied in a passive mode. In POC, the commanding reactive agent hydroxyl is also the key to the purifying process.

Germicidal ultraviolet (UV) light is commonly shone on a catalyst (usually titanium oxide) to yield hydroxyl, oxygen and blanch, all of which are potent oxidising agents that are very effective at destroying the organic structure of micro-organisms and gaseous volatile organic compounds.

Comprehensive defence is the key strength of POC technology. Proponents of this technology claim that POC inactivates ALL categories of indoor pollution, including:

(1) above ground particulates i.e. dust, pet dander, plant pollen, sea salts, tobacco smoke, industrial and car pollution, etc

(2) bioaerosols i.e. communicable biological compounds (e.g. pathogenic bacteria and viruses) or non-contagious and non-communicable (e.g. non-pathogenic bacteria, molds, cell debris)

(3) volatile organic compounds (VOCs) i.e. gaseous chemicals or odours – benzene, toluene, chloroform, ethanol, formaldehyde, etc, all common emissions from everyday products of our modern home.

Detractors of POC technology are wary of the incapacity of hydroxyl to characterize between the organic structures of molecular contaminants and that of our nose membrane, lung tissue and eye cornea.

Electrostatic Filter

This technology appears to have originated in heavy industries which bent abundant pollutants. The predictable electrostatic filter ionic air cleanser includes two electrodes sandwiching a porous dielectric material. The dielectric material impedes electrical conductivity whilst the electrodes efficiently conduct electricity.

Impure air is drawn into the electrostatic puriifer and made to pass over the dielectric material which acts like a sieve. The electrostatic field made between the electrodes causes above ground particulates i.e.smoke contaminants, dust, etc, to adhere to the dielectric go up. From the other end of the cleanser, purified air emerges.

An ion source is often placed before the electrostatic filter to impart an gripping charge to the above ground particulates. These impurities, so charged, stick more successfully to the dielectric material.

Criticism of electrostatic filter technology focuses on ozone as a by-product, commonly assumed to be bent in all ionisation processes.

Combo Ionic Air Purifiers

To cater to the various adherents and critics of the diverse technologies, combos incorporate all or some of the above types of technologies. Combos may contain:

(1) adsorptive materials such as activated carbon or oxygenated charcoal (known for its extremely porous large go up area) are added to POC technology to enhance the removal of VOCs;

(2) oxidizing catalysts like titanium oxide are coated on various gears of all types of air purifiers to enhance VOC elimination;

(3) reducing catalysts such as manganese dioxide are coated near the exit outlets of many air purifiers to reduce reactive species like ozone and nitric oxide which may be harmful;

(4) generating ions by differing methods such as using microwave, UV light, radio frequency waves, and direct contemporary;

(5) tweaking the specifications of any ionic air cleanser technology so as to attain the well-known HEPA status lacking really using HEPA filters.

Observably, the process of selecting the most well-methodical and effective ionic air cleanser involves analysing a deluge of information. And I have not even touched on the safety aspects of each technology. I have also not considered in detail the claims of each technology. So before you place your money down for any air cleanser in your homes, offices, schools, etc, check back here for updates as I take up again my quest for the ideal ionic air cleanser.

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