What Kind of Filters Are Required for an Air Purifier to Work Efficiently?
Air purifiers are becoming increasingly common in India due to the rising levels of air pollution in major cities. Also, people have become more aware of the health issues caused by indoor and outdoor pollution, and are opting for home air filtration products. If you are also looking for an indoor air filtration system, there are a few basic things you must know about these products. Here is our guide for buying an indoor air filter and purifier for your home or office.
Air Filtration Technology
There are two types of air purifiers, Active and Passive. Active air purifiers use ionisation for cleaning the air. Which means they release negatively charged ions in the ambient air, causing pollutants to stick to surfaces. While they do get the job done, there is a downside to their functioning – they may release Ozone as a by-product. Passive air purification units on the other hand use air filters to remove pollutants. They are more efficient since all dust and particulate matter is permanently removed from the air and collected in the filters.
Read More: Technology Behind Honeywell’s HiSiv Filter
Types and Function of Air Filters
To be effective, air purifiers need a multi-stage air filtration system. A multi-stage air filtration product generally has three types of filters.
The pre filter acts as the first line of defence and removes PM10 pollutants such as dust, smoke, hair, pet dander, large pollens etc. The pre filter also helps in increasing the life of the secondary filter by not letting it choke sooner. Due to the difference in the kind of pollution and the difference in it, pre-filter is not seen in the air purifiers in the United States and Europe; however, it becomes of paramount importance in countries such as India and China.
The High Efficiency Particulate Air Filter traps PM2.5 pollutants which are too fine to be stopped by the Pre Filter. They can filter particles of up to 0.3 microns in size. HEPA filters are considered as the industry standard for air filtration products. These filters can remove up to 99.97% of pollutants from the air.
This filter is used for removing volatile organic compounds (VOCs), gaseous substances and odours from the air. Some brands use their own patented filters in place of these filters, such as the HiSiv filter used by Honeywell air purifiers.
Filters in Car Air Purifiers
Cars usually have a pre-filter installed in their fan unit (blower), so Car Air Purifiers can make do with just HEPA and Carbon filters.