Choosing the right air purifier can be an important decision but a hard one too. Though there are a number of air purifiers designed to remove different kinds of pollutants and air borne particles, still deciding on the best air purifier is a tough choice, as people might be allergic to different particles and the needs might vary accordingly. Here are a few comparisons between some popular air purifiers, which may help you in deciding on the best air purifier for you.

Air Purifiers with High Energy Particle Arresting (HEPA) filters were initially designed for the Atomic Energy Commission and are normally used for the commercial cleaning rooms to eliminate the dust and other air-borne pollutants. These filters are in the form of paperpolymer sheets consisting of tiny holes, just sufficient enough for the air to pass through. In fact they are so small, that a large surface area is required for a substantial amount of air to flow through the sheet. Owing to this cause, the filters are designed in a zigzag or accordion pattern to provide a large surface area to a considerably smaller area.
Another version of this technology utilized by a few manufacturers is increasing the hole sizes to let air pass through, but it is charged with electrostatic wands, resulting in restriction of the smaller particles to pass through, which are trapped. The HEPA filters have proved to be successful in the home segment. The drawback with these filters ids that they need to be replaced every 6 months, or in a few years (up to 5 years), depending on the manufacturer. Prior to  finalizing and making a purchase, other factors like the noise created by the fan, amount of air-pass-through, the filter’s life span, and the cost of the replacement filter and the complete cost of the system. These are normally the points and factors considered while reviewing the HEPA filtered unit.

There are other filters on the market which use the UV technology, commonly the Ultra- Violet light, to produce air purifiers. It is a common fact that these rays are effective in eliminating the micro-organism’s DNA, which includes viruses and bacteria. The drawback with these purifiers is that they have not proved to be successful in eliminating all gas pollutants and air borne particles. Though, the UV purifiers can be clubbed together with another air purifier, to make them more efficient.

Another type of air purifiers available is Ion Generator purifiers, which emit a stream of negatively charged ions, which charge the pollutant and when they collide, the pollutants, are trapped, owing to the electronic charge. Such devices are generally used by the poultry industry and the United States Submarines to remove the feather dust.

But there are a lot of disadvantages with these types of air purifiers. It has been observed that the strains of the trapped pollutants are left behind causing a black area near the machine. Also they are only suited in localized areas because they do not have fans. The most important disadvantage is that some of these may even emit Ozone, which can be quite dangerous and are not equipped to eliminate gases.
It is clearly visible using these three examples, that there are a lot of differences in air purifiers. You may consider in-depth research and compare different models, before picking on the one, which best suits, your need. Your judgment should not be based on market promotions or hearsays; else you might end up choosing the wrong air purifier, which would be worth nothing.