What are the considerations for and against buying a charged media electrostatic air purifier? In just one minute, let me reveal the most important ones.
A charged media filter is one that collects particles by static charge. Using this technology it is possible to collect particles as small as 0.1 micron.
An example would be the 3M Filtrete media many people use in their furnace and HVAC systems. The Ultra Clean 3M air purifier uses this same media and is a good example of a relatively inexpensive but highly effective electrostatic air purifier.
These filters start with an efficiency as high as 90 percent. But as the surface becomes clogged with particles efficiency decreases. The greatest efficiency loss is in the smallest particle sizes since the electrostatic charge is used up with each particle capture.
These filters do not work like HEPA filters and cannot remove microscopic particles mechanically since the media is not as fine. It will continue to filter larger particles better than an ionic air cleaner because the media is small enough to not need the attraction of opposite charges used for smaller particles.
The main advantage is that you can clean a very large volume of air quickly with low air resistance. This means you don't need as powerful a fan and there will be much less noise produced. The Ultra Clean 3M air purifier mentioned earlier can be very quiet while still having a clean air delivery rate 13 times greater than the more expensive Sharper Image Ionic Breeze.
The main disadvantage to this type of electrostatic air purifier is the cost of filter replacement, typically recommended every 90 days. And of course the gradual efficiency drop as the filter becomes dirty means that your air is a little less clean with each passing day. But for many people they do provide good allergy relief.