| It has become evident in the past decade or so | | | | particles which cannot pass through or go around |
| that many people living in urban and even | | | | walls. Negative ions also cannot be channeled |
| suburban areas are increasingly experiencing | | | | through metal heating and cooling ductwork where |
| respiratory issues due to dirty air. With that | | | | they would be grounded. Standard air purifiers are |
| increase it has become increasingly more popular | | | | designed to remove particles from the air such as |
| to use some sort of air filtration to help breathe | | | | dust, pollen and pet dander, while specialized filters |
| easier. In the marketplace today, there are two | | | | can be highly effective in removing odors, gases, |
| popular methods of filtration, HEPA and ionic. | | | | chemicals and smoke. In general, air cleaners clean |
| HEPA filter technology is among the best | | | | the air in one of three ways: by collecting particles |
| technology available for air cleaners. It is a very | | | | in filters (either mechanical or electronic), by |
| effective system but the filters must be changed | | | | creating an ionic (static) charge to attract particles |
| to remain effective. HEPA filters were originally | | | | onto a collection plate, or through some |
| developed by the Atomic Energy Commission to | | | | combination of these methods. |
| protect the respiratory system from radioactive | | | | Effective portable air purifiers will eliminate at least |
| chemicals. Although costs can range up to a | | | | 99% of airborne pollutants that pass through their |
| couple of thousand dollars, it is possible to | | | | filters, capturing particles such as dust, pollen, pet |
| purchase an air purifier for about $600 that will | | | | dander, and smoke. Some air purifiers are even |
| control and remove such VOCs as mineral spirits | | | | effective at fighting germs such as bacteria, |
| and petroleum-based solvents in areas up to 1,500 | | | | viruses, mold spores and fungi. Effective air |
| square feet. HEPA filters in your home furnace | | | | purifiers, like Honeywell air purifiers, eliminate at |
| can effectively reduce irritants that may trigger | | | | least 99% of airborne pollutants that pass through |
| asthma. | | | | their filters, capturing common allergens such as |
| HEPA filters have a fine 0.3 micron mesh that can | | | | dust, pollen, pet dander and smoke. Effective and |
| filter most pollutants and allergens in the air, but | | | | relatively inexpensive, HEPA filters were first |
| are not capable of filtering out smoke, fumes and | | | | developed to remove radioactive particles from |
| odors. They are noisier but often more effective | | | | the air in nuclear facilities. The government has |
| than other air purifiers. It is a very effective air | | | | established a HEPA definition: In order for a filter |
| purifying system but the filters must be changed | | | | to be designated as HEPA, the manufacturer |
| to remain really effective. | | | | must demonstrate that it absorbs and removes |
| Standard ionic air purifiers are limited to creating | | | | at least 99.97% of 0.3 micrometer airborne |
| ions in only a single room as ions are physical | | | | particle pollutants. |