Bag (pocket) filters
Pocket filters that hold more dust for longer service life.
G3 – G4 coarse and M5 – F9 fine bag filters for primary and secondary stages in air handling units, including premium energy saving grades.
Typical use
AHU primary and secondary
G3 – F9
coarse to fine grades
300 – 625mm
pocket lengths
Energy saving
low resistance option
Next-day
on stocked synthetic sizes
The bag filter range
Three constructions, each with a full specification
Choose a type to see its filter grade, media, header, pocket lengths and standard sizes.
G3 – G4G3 – G4 bag filters
Stand-alone or pre-filter
- ISO 16890
- ISO Coarse 50% – 60%
- Pocket lengths
- 300mm – 625mm
- M5 – F9
M5 – F9 synthetic bag filters
Secondary filter, HEPA pre-filter
- ISO 16890
- ePM10 55% – ePM1 85%
- Pocket lengths
- 300mm – 625mm
M5 – F9M5 – F9 premium energy saving bag filters
Energy saving secondary filter, HEPA pre-filter
- ISO 16890
- ePM10 55% – ePM1 85%
- Pocket lengths
- 300mm – 625mm
Compare bag filter types
| Specification | G3 – G4 | M5 – F9 synthetic | M5 – F9 energy saving |
|---|---|---|---|
| EN 779 | G3 – G4 | M5 – F9 | M5 – F9 |
| ISO 16890 | ISO Coarse 50% – 60% | ePM10 55% – ePM1 85% | ePM10 55% – ePM1 85% |
| Media | 100% polypropylene pockets | 100% polypropylene synthetic, two-stage | 3-layer fibre media, endless edge-welded pockets |
| Header | Galvanised steel | Galvanised steel, metal or plastic header | Galvanised steel |
| Header depths | 20mm, 25mm | 20mm, 25mm, 30mm | 20mm, 25mm |
| Pocket lengths | 300mm – 625mm | 300mm – 625mm | 300mm – 625mm |
| Max temperature | Standard HVAC | Up to 80°C | Up to 80°C |
| Availability | Non-standard sizes made to order | Stocked sizes next-day, non-standard made to order | Non-standard sizes made to order |
A high-capacity workhorse
Long dust holding capacity for typical ventilation loads
Pocket filters use a large media area folded into pockets, giving a long service life and lower running resistance than a comparable panel filter.
Large media area
Multiple pockets extend the time between filter changes.
Lower resistance
Energy saving grades reduce fan energy over the filter life.
Matched airflow
Pocket count and length selected around the system duty.
Header options
Header depths and metal or plastic frames to suit the housing.
Specification options
The information needed for an accurate quote
Confirming the housing and duty helps select the right grade, pocket count and length.
| Variable | Typical information to confirm |
|---|---|
| Filter grade | Required grade, from G3 to F9 |
| Face dimensions | Height × width of the housing |
| Pocket length | 300mm – 625mm |
| Pocket count | Number of pockets for the airflow |
| Header | Header depth and metal or plastic frame |
| Quantity and site | Demand, delivery point and change plan |
Common applications
Where bag filters are used
- Air handling units
- General ventilation
- Commercial offices
- Hospitals
- Computer centres
- Pharmaceutical
- Food industry
- HEPA pre-filtration
Not sure what is fitted?
Start with what you can see
The label, face size, pocket count and pocket length are a useful starting point. For larger or mixed estates, a site survey can create a clearer asset record.
Bag filter questions
Useful answers before you specify
Bag filters offer a much larger media area, so they suit systems where longer service life and lower running resistance matter, typically as the main filtration stage in an air handling unit.
Technical help without the hard sell
Send your bag filter housing details
Face size, pocket length, pocket count, grade and quantity, or a photo of the existing label, help Maxi confirm the right specification.