The first rule to improve your indoor air quality is to ventilate in order to recycle the fresh air. But what if the outdoor air is really bad? Or the climate extreme ? If you live in cold Norway, hot and humid Singapore or foggy Beijing, you may be considering to buy an air cleaner (also called air purifier). In Asia, air cleaners are becoming a common home appliance that people buy, like they would buy vacuum cleaners. Many technical words are used to describe working processes of air cleaners: electrostatic precipitators, HEPA filters, ionizers, sorbents, plasma, UVPCO, etc.
This post is aimed at helping you to see clearer and understanding the basic principles of these different technologies, as well as their potential risks. Be aware that there is no proper certification for air cleaners. So consumers are left with no choice but to believe the claims of air cleaner manufacturers. Indoor air pollution is not visible, which make it easy for companies to claim efficiency, even when the device provides no significant improvement. Finally, there is no requirement to test side-effects, such as ozone emissions. So consumers need to check the technical parameters to ensure a safety.
Most air cleaners combine different technologies. There are three major technologies commonly used to remove particles:
- Mechanical filters
- Electrostatic precipitators
and three main technologies targeting gas pollutants
- Plasma System
A good start to get a basic understanding of air cleaning technologies is the EPA summary on Residential Air Cleaners.