G3–F9, ISO 16890 and HEPA
Why legacy grades cannot be mechanically converted to new ones and what to demand in a test report.
G3–F9, ISO 16890 and HEPA explained
- Designation
- G3, G4; ISO Coarse
- Meaning
- G3/G4 are legacy EN 779; ISO Coarse is ISO 16890
- Procurement rule
- Specify standard, airflow, initial/final ΔP and test report
F5/F6 labels still appear in older catalogues. Before replacement, always verify the stated standard edition and the certified report for the exact filter.
How to build a ventilation cascade
The first stage removes coarse dust, the intermediate stage protects the final filter and the final stage delivers the target cleanliness. Check the solution against total ΔP, dust holding, moisture, frames and fan capacity.
G3–F9 may identify legacy requirements; a new selection needs test evidence to the applicable ISO 16890 edition.
Terms used in the report
- ISO ePM1 — the ISO 16890 efficiency group referenced to the PM1 fraction.
- MPPS — the particle size at which a HEPA filter shows its minimum efficiency.
- ΔP — pressure difference between inlet and outlet, a filter loading indicator; the report states initial and final values.
Frequently asked questions
How should G4, F7, F9 and ISO ePM1 be compared?
Identify the standard first. G/F are legacy EN 779 grades; ISO ePM belongs to ISO 16890. There is no exact universal conversion: compare test reports at equal airflow and ΔP.
Can you match an OEM reference?
Yes — once dimensions, seal, media, grade or rating, flow and conditions are confirmed. A code alone, without checking the parameters, can lead to a wrong selection.
Ventilation filters in 3D
Related pages
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Open →Ventilation & clean airG3–F9, ePM, HEPA and ULPA: panels, pockets, V-bank, compact cells and final filters — selected by airflow, ΔP, climate and required cleanliness, from ordinary ventilation to ISO 5 cleanrooms.
Open →An engineer will answer your question
Send your process data — we will review the specification, flag missing measurements and propose a process arrangement.