Air Purification Systems
The two most common types of air cleaners available for in home use are the particulate filtration system and the electrostatic precipitator system. There are several different brands of each type available. The filtration systems include HEPA (High Efficiency Particulate Air) filters and Electret Systems. According to Consumer Reports Magazine, the HEPA types are very efficient, as they remove up to 99.97% of particles as small as 0.3 microns (a micron is about 1/25,000 of an inch; we can see dust particles in the air down to about 10 microns). Their downside is that their filters (which are fairly expensive) require frequent replacement, and they have a high energy cost due to their powerful fans. The Electret Systems feature fairly low energy costs and are relatively efficient when new. Their downsides are their high maintenance costs, and the fact that their efficiency decreases as they are used. Both electrostatic precipitators and negative ionizers utilize pre-filters to catch the larger particles, followed by electric charges to trap smaller particles. They both feature low energy costs and little or no filter replacement costs. The electrostatic precipitator does require periodic cleaning to remain at highest efficiency level, while the negative ionizer can cause charged particles to stick to and soil walls and furniture. Also, they both can produce low levels of ozone during their operation.
One type of air purification system that has received negative recommendations from many experts is an Ozone Generator. These systems move air across a high-voltage plate, thus initiating the formation of ozone molecules. While the odor of ozone does give the impression of clean smelling air, ozone is a widely recognized respiratory irritant that can bother your nose, throat, lungs, and eyes. Many commercially available ozone generators can produce ozone levels that are well above those recommended by both OSHA (the Occupational Safety and Health Administration), and the FDA (Food and Drug Association).
When shopping for air purification systems, portable units can be compared using several yardsticks. These would include the efficiency rating (how well they collect pollutants from indoor air, expressed as a percentage), the total air flow rate (how much air it draws through the filtering or cleaning element, usually measured in cubic feet per minute), and the clean air delivery rate (known as the CADR: the number of cubic feet of clean air that the unit delivers per minute). In addition to the above mentioned portable units, larger units that are designed to fit into the ductwork for central heating and air conditioning systems are also available. These are designed to address air quality issues that involve the entire house. They do, however, also feature a higher price tag. Thus, if you only need to clean the air in a few rooms, a portable model is often preferred.
Several consumer advocates, in fact, recommend saving hundreds of dollars by just opening a few windows, and using the kitchen exhaust vent. No matter what, a little fresh air can go a long way toward improving the air quality within your home!