Thursday, December 20, 2012

Air Purifier

Happy End of the World!

I bought an air purifier lately. You know, the air in Kuala Lumpur is polluted. An air purifier – sometimes called air cleaner – removes contaminants from the air, and helps boost our health.

There are many types of air purifiers in the market. If you are shopping for one, but are confused of the various technologies used, I give you some clues here…

HEPA Filter

HEPA stands for High Efficiency Particulate Air. An air cleaner using HEPA filter removes up to 99.97% of 0.3 micron particles. This is the most commonly used technology.

One drawback of this technology is that HEPA filters need to be replaced after a year or two, and they are costly.


Ionizers disperse negative ions into the air. These ions attach to airborne particulates. The electrically charged particulates in turn bond with each other and settle to the floor or wall.

Moisture discharges the ions. Therefore, this technology is less effective in humid places. In Malaysia, this essentially means ionizers only work inside air-conditioned rooms.

Another concern is that ionizers generate ozone, a lung irritant.

Water-based Air Refresher

A water-based air refresher, like the one shown above, sucks air into the water. Presumably the pollutants will dissolve in the water.

I have got one such device. I found its air flow to be quite weak, compared to a typical air purifier with HEPA filter. While I observed that the water was dirty after a day in use, it was not as effective as I wish to be.

Note that I added aromatherapy solution to the water, and the air which came out of it was very revitalizing. This device failed as an air cleaner, but it did serve other purposes.