Primary (pre) air filters G1-G4 protect downstream stages and cut cost. Compare panel, pocket, roll and washable types, with specs and a practical selection checklist.
1차 vs 중효율 vs 고효율 필터: 나란히 비교
A one-page comparison of primary (G1-G4), medium (F5-F9) and HEPA/ULPA (H10-H14) air filters-efficiency, pressure drop, life, cost and where each belongs.