# F8 Medium Efficiency Bag Filter

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> Last updated: 2026-09-20 16:13:23

Medium Efficiency bag filters are typically used as pre-filters for HEPA filters and terminal filters in air conditioning systems, reducing the load on high efficiency air filters and extending their service life.

An F8 bag filter is the last medium-efficiency stage before HEPA. At 90 to 95 per cent it takes the fine fraction that the coarser pocket grades pass, which is what makes it the standard choice for the pre-filter position in a cleanroom or a pharmaceutical air handling unit.

It shares the F5 to F9 pocket format — three, six or eight bags in a 592 mm frame, 2.80 to 5.68 m² of media. Because the media does more work per pass, resistance sits higher than on the coarser grades: 115 to 120 Pa initial against a 450 Pa final. Set the differential-pressure gauge at 450 Pa and the element runs its full service interval.

It is also the grade to step up to when an F7 is no longer holding the room: the holding frame and the 592 mm face are identical, so the change is an element swap rather than a housing modification.

## Key features

- **Filtration efficiency**: 90% – 95% (EN779 F8, the last medium-efficiency stage before HEPA)
- **Rated airflow**: 1,700 – 3,400 m³/h (3, 6 or 8 pockets matched to the volume handled)
- **Initial resistance**: 115 – 120 Pa (Declared per size at its rated airflow)
- **Final resistance**: 450 Pa (Set the differential-pressure alarm at 450 Pa)
- **Large media area**: 2.80 – 5.68 m² (Pocket geometry keeps resistance low while holding dust)
- **Protects HEPA**: Upstream of H13 (Cuts the load on terminal filters in cleanroom and paint-booth trains)

## Specifications

- Filtration grade: F8 (F9 available in the same frame)
- Efficiency: 90% – 95% (EN779 F8)
- Media: Non-woven synthetic fibre, or glass fibre
- Frame: Galvanized steel or aluminum
- Standard sizes: 287×592×550, 592×592×550, 592×592×600 mm
- Pocket count: 3, 6, 8
- Media area: 2.80 – 5.68 m²
- Initial resistance: 115 – 120 Pa
- Final resistance: 450 Pa
- Rated airflow: 1,700 – 3,400 m³/h
- Target particles: High-efficiency medium filtration upstream of HEPA

## Applications

Cleanrooms, Pharmaceutical Production, Electronics Manufacturing, Automotive Paint Booths, Hospitals, Food Processing

## Product Features

- Design & Durability: Large open-bag design for low energy consumption, stable performance, corrosion resistance, and easy recycling.
- Efficiency & Performance: 90%-95% efficiency; ultrasonic welded edges and electrostatic fiber media ensure airtightness, sub-micron particle capture, high dust capacity, and long service life.
- Material & Size Options: Special non-woven or fiberglass media with galvanized steel or aluminum frames; standard and custom sizes available.

## Technical Parameter