Air Purifier Encyclopedia: Definition, Principles and Buying Guide

First paragraph: content overview
An air purifier is an electrical device that improves indoor air quality through filtration, adsorption or decomposition technology. Its core functions include removing pollutants such as particulate matter (such as PM2.5), formaldehyde, odors and bacteria.This article will start fromWorking principle,Core functions,Applicable scenariosandKey points for purchasingIt is expanded into four parts to help users fully understand its value.Among them, filter type (HEPA, activated carbon) and CADR value (clean air output rate) are the key points, while intelligent control, noise, etc. are secondary considerations.

Paragraph 2: Working Principle and Technology
Air purifiers mainly passPhysical filtering(such as HEPA filter to intercept particulate matter),chemical adsorption(Activated carbon removes formaldehyde) andIonization technology(Negative ion sterilization) three ways to purify the air.Take Philips AC3256 as an example. It uses a "multi-layer composite filter" that can filter particles above 0.3 microns, and the formaldehyde removal rate has been measured to reach 90% (data source: 2022 report of China Household Electrical Appliances Research Institute).Different technologies have their own advantages and disadvantages. For example, ionization technology may produce ozone, so you need to pay attention to national safety standards.

Paragraph 3: Core functions and performance indicators
The key to measuring purifier performance isCADR value(unit m³/h), the higher the value, the faster the purification efficiency.For example, Xiaomi Air Purifier 4 Pro has a particle CADR of 500m³/h and is suitable for a space of 35-60㎡.In addition,CCM valueReflecting the life of the filter, P4 (particulate matter) and F4 (formaldehyde) are the highest levels.According to tests by the Shanghai Environmental Protection Association, the CCM value of 352 X86C exceeds the national standard by three times, making it suitable for long-term use.

Paragraph 4: Applicable scenarios and usage suggestions
Air purifiers are especially suitable for newly renovated houses (removal of formaldehyde), areas with high incidence of haze (prevention of PM2.5) and people prone to allergies (filtration of pollen).Doors and windows should be closed during use and the filter should be replaced regularly (usually 6-12 months).Models such as the Dyson HP09 also have a heating function, but experts remind (Song Guangsheng, director of the China Indoor Environment Monitoring Working Committee): "Combined functions may distract from purification efficiency, so priority needs to be given to core performance."

Paragraph 5: Summary and purchase points
Taken together, you need to pay attention when purchasingCADR/CCM matching space size,Filter costandNoise control(recommended ≤60dB).Mainstream brands such as Blueair and IQAir focus on the high-end market, while Xiaomi and Huawei are known for their cost-effectiveness.Consumers can refer to the "New National Standard for Air Purifiers (GB/T 18801-2022)" and make choices based on their own needs. Do not blindly pursue promotional terms such as "99.9% sterilization".

Quote sources:
1. China Household Electrical Appliances Research Institute "Air Purifier Performance Test Report" (2022)
2. Public interview with Song Guangsheng, Director of China Indoor Environment Monitoring Working Committee
3. Shanghai Environmental Protection Association "CCM Value Comparison Experimental Data" (2023)
4. National standard GB/T 18801-2022 "Air Purifier"