1. Metal filter: filter larger solid particles (mainly used in R22 and the use of mineral oil and other small and medium systems that are not sensitive to moisture).
2. Polyester filter: filter tiny particles.
3. Glass wool: filter tiny particles.
4. Molecular sieve: filter large solid impurities, mainly to absorb water, which is 3-4 times that of other substances, and can also absorb nearby acidic substances.
5. Activated alumina: absorbs water, mainly acidic substances.
6. Activated carbon: absorbs paraffin, but because the refrigerating oil only precipitates paraffin when the temperature is lower than -35 degrees, it is not necessary to use it in the system operating at medium and high temperature.
