Common Air Filtration Materials and Their Uses

1. HEPA Filters: Widely regarded as fine-dust killers, they can filter particles 0.3 micrometers and larger, including PM2.5, pollen, and dust, with an efficiency of more than 99.7%. They are a core component of household air purifiers, but must be replaced regularly or their performance will decline.

2. Activated Carbon: Its porous structure adsorbs odors and harmful gases, capturing substances such as formaldehyde, TVOCs (volatile compounds released by renovation materials), and cooking fumes. However, its adsorption capacity is limited and it saturates easily, so it must be aired out or replaced regularly; otherwise, it may release pollutants back into the air.

3. Electrostatic Electret Materials: These materials carry a static charge that attracts charged dust and bacteria. They do not require frequent replacement, create little airflow resistance, and operate quietly, making them suitable for use with HEPA filters. However, they are less effective at filtering larger particles.

4. Photocatalytic Materials: Used together with ultraviolet light, these materials can break down harmful gases such as formaldehyde and benzene into water and carbon dioxide, providing continuous purification without being consumed in the process. Because ultraviolet light can affect the human body, photocatalytic materials are normally installed inside the purifier and should not be directly exposed.

5. Antibacterial and Antiviral Materials: Silver ions, copper ions, or similar agents are generally added to the filter surface to inhibit the growth of bacteria and viruses and prevent the filter itself from becoming a source of secondary contamination. They are well suited to homes with elderly people or children and are especially useful during flu season.

These materials are often used in combination. For example, a HEPA filter, activated carbon, and an antibacterial layer can remove dust, eliminate odors, and inhibit microbes at the same time. When choosing an air purifier, check which materials it uses and select one suited to your household's needs, such as formaldehyde removal or allergy relief.