How does Ionic Air Purifier Technology Work?
Most people are unaware that there are at least 4 different types of ionic air purifier in use today. Ionizers have been around for many years.
How effective are they?
Definition of an ion - an atom or molecule, electrically charged, which has lost or gained one or more electrons, making it positively or negatively charged.
A simplified explanation of the process: The ionic air purifier produces ions. The ions attach themselves to particles (opposite charges attract). The particles attach themselves to other particles or collection devices or charged surfaces and are removed from the air. The details depend on the type of ionic air purifier used.
Ionization and ions are produced and are present in the air we breathe outside. Ions are measured by how many are present in a cubic centimeter or cm3. "Typical" clean air outside contains 3000 positive(+) and 4000 negative(-) ions per cm3. This amount can be influenced by a myriad of factors and is constantly changing and constantly replenished by sun, wind, and storms.
After detailed research it is my conclusion that the natural balance of ions outdoors is generally better than our indoor environments.
Have you ever felt like getting outside to get a breath of fresh air? Interestingly enough, some scientists point to +/- ions as part of the reason for outside air "feeling right".
Now, unfortunately indoor air does presents a problem for ions. In most cases the number of ions is drastically reduced compared to outside air.
Sometimes there are too many positive ions and an imbalance occurs. Generally the imbalance leans towards the positive, but another problem could occur if too many negative ions are present. A balance is best, just like outside.
Ok, you say, what about cleaning the air?
The information presented thus far will help you make more sense of the different ionic air purifier technologies used to clean the air:
1) Electrostatic precipitators and charged media filters - Mainly a passive technology; most ionization occurs inside the air purifier. For details, refer to the page on this technology in the "passive" section.
2) Single charge ionizers (+ or -) - an active technology generally emitting just negative ions. This technology has some possible benefits as well as a host of possible negatives. Benefits: does remove particles and some research has shown health benefits of more negative ions. Negatives: particles tend to stick to other particles, walls, tables, everywhere ... and too many negative ions could upset the optimum balance
desired between positive and negative ions in the air. Many indoor environments have a surplus of positive ions ... this may be why some have reported great results with the added negative ions. Common sense points to an unbalance developing when you keep adding the negative ions either in the short or long run.
You may have also heard of "black wall syndrome". This is where many particles are negatively (-) charged by ions and then are attracted and "cemented" to a positively (+) charged wall. Interesting interior decorating for sure.
3) Double charge ionizers (+ and -) - an active technology emitting both positive and negative ions. This technology is very effective and minimizes on both the "black wall syndrome". It also keeps a better balance of negative and positive ions. Particles will be attracted to each other again and again, forming larger particles too heavy for the air. They are eventually vacuumed or dusted up.
4) RCI (radiant catalytic ionization) - an active technology that is currently available in an ionic air purifier with just a handful of companies. It is a combination of technologies wrapped in one air purifier. Technologies include UV and RF pulse ionization (+ and -) as well as a few other proprietary ones described as ActivePure (RCI) cell. The documented results are impressive.
Wikipedia has general background
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Do your homework.
Because there are several versions of this technology, it can be hard to select the right one. I would stay away from single charge ionizers all-together. Even within the other technology types you need to search diligently for a quality ionic air purifier. Realize that there are really only a handful of companies with a "trust factor" track record. Be wary of the others as marketing hype as well as copy cats and small time vendors exist.
Lastly, the RCI version has a replaceable UV lamp or RCI cell that will need to be replaced every few years. Know and calculate the ongoing cost before purchasing.
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