The key component of the air purifier is the strainer. After a period of time, the filter needs to be replaced, otherwise it will not only purify the air, but also become an indoor air pollution source. It is important to change the screen regularly. The service life of different filters is different, short 1-2 months, depending on the use of environmental pollution, the life of the screen will be different. Most purifiers have filter replacement reminders to remind users to replace the filter in a timely manner. Depending on the material and structure of the filter, the price difference is large, ranging from hundreds of to thousands of yuan Air purifier in the purification of air at the same time, its own will also produce some harmful substances, such as ozone, ultraviolet, TVOC, PM10 and so on.