So, you want to buy an airpurifier in India? (2/2)

General tips for getting the right air purifier

At the minimum, go for a model that has a pre-filter and the HEPA filter. The pre-filter will be the first line of defense and will filter out the large particles and most of the dust. The HEPA will filter out the finer dust particles (and sometimes the viruses etc.)

• Pre-filter : This is mandatory for a country like India, where the dust particles in the air is quite a bit. The degree of pollution will typically require you to change the filter every 3 months. 
• You would rather this be the pre-filter than the HEPA filter (which is typically more expensive)

NOTE: A word about other purifiers that uses ionization / plasma technology. These are known to produce low amounts of Ozone (that are under the acceptable Ozone exposure at lower altitudes). Ozone is known to be harmful for the lungs. So, please do your research to determine if the features / functionalities and safety options provided these purifiers compensate for the potential risk.

SIZE

• Choosing the right "size" / "capacity: This is done based on "CADR rating" of the purifier. This signifies the volume of air that the purifier gets to push through it's systems and clean it. CADR ratings are stated for dust, pollen and smoke.

• In general, it is recommended to buy a slightly larger device than what your room needs so that it can work effectively even at low speed (might result in lesser sound and power consumption). Also, given that it's a one time investment for some time, don't be restricted by just today's needs alone.

Other potentially useful features you can look out for

• A device that indicates the air quality (with a light such as Green, Yellow, Red will be useful). This is not mandatory of course but is preferred.
• You can look for a filter that has a timer (auto-start?) so that you can program it to turn on automatically about an hour before you get home.
• Wall mounting options will be terrific.
• Most models are mobile and are designed to be kept on the floor (and can be moved around easily). 
• However, if you plan on keeping the purifier in a static location in the room, then look for wall mountable options (which will result in saving of some space on the floor).