Cassette Filter (ZIG ZAG)
Cassette Filter (ZIG ZAG) is a panel-type air filter designed for pre-filtration in ventilation and HVAC systems. Its synthetic filter media is arranged in a zig-zag form and installed inside a metal frame.
Compact G3 and G4 Class Pre-Filtration
The zig-zag filter structure provides a larger filtration surface than flat filter media. Therefore, it helps capture coarse particles in a compact cassette. It also promotes more uniform use of the filter surface.
Cassette filters are available in standard and high-capacity versions. They can be manufactured in 48 mm and 96 mm depths with galvanized metal or stainless steel frames.
ISO Coarse
Used to capture coarse particles and protect downstream filtration stages.
G3 and G4
Provides G3 and G4 performance options according to the former EN 779 classification.
48 and 96 mm
Two standard depth options are available according to the filter housing and pressure-drop requirements.
Up to 80°C
Suitable for operating temperatures up to 80°C with the appropriate filter media, frame and gasket selection.
What Is a Cassette Filter?
A cassette filter is a compact pre-filter in which synthetic fiber filter media is folded into a zig-zag form and fixed inside a metal frame. The zig-zag form provides a larger filtration surface area within the same face dimensions.
Single-sided or double-sided expanded metal support can be used to help prevent deformation of the filter media under airflow. In addition, different gasket options can reduce air leakage between the frame and the filter housing.
Product selection should consider airflow, face velocity, filter class, filtration area, initial pressure drop, operating temperature, ambient humidity and installation dimensions.
Operating Principle
Dirty Air Inlet
Air containing coarse dust and fibers reaches the face of the cassette filter.
Flow Through Zig-Zag Media
Air passes through the synthetic fiber filter media with its large surface area.
Particle Capture
Coarse particles are captured by the filter fibers, reducing the airborne contaminant load.
Filtered Air
Air with reduced coarse contaminants is directed to the next filtration or air-conditioning stage.
Technical Specifications
| Technical Parameter | Value | Technical Parameter | Value |
|---|---|---|---|
| Filter Standard | ISO 16890 | Recommended Final Pressure Drop | Initial ΔP + 50 Pa or initial ΔP × 3, whichever is lower |
| Filter Class | ISO Coarse | Maximum Operating Temperature | 80°C |
| Filter Media | Synthetic fiber | Standard Depths | 48 and 96 mm |
| Frame Type | Galvanized metal or stainless steel | Media Support | Single-sided or double-sided expanded metal |
Product Coding Table
| Filter Type | Filter Class | Frame Type | Expanded Metal | Capacity | Dimensions | Gasket Type |
|---|---|---|---|---|---|---|
| GZ: Zig Zag Filter | G3 G4 |
G: Galvanized metal | 1: Single-sided 2: Double-sided |
M: Standard H: High |
Width × Height × Depth
Example: 592 × 592 × 48 mm |
W: No gasket P: Cast gasket PP: Double-sided cast gasket E: EPDM gasket EE: Double-sided EPDM gasket C: Grey EPDM gasket CC: Double-sided grey EPDM gasket |
GZ-G4-G-2-H-592-592-96-W
GZ = Zig Zag Cassette Filter
G4 = Former EN 779 filter class
G = Galvanized metal frame
2 = Double-sided expanded metal support
H = High-capacity construction
592-592-96 = Width, height and depth
W = No gasket
Standard Capacity Models
The reference performance values for standard-capacity cassette filters identified by the letter M in the product code are shown below.
| Filter Model | EN 779 Withdrawn |
ISO 16890 | Dimensions W × H × D |
Filtration Area m² |
Nominal Airflow m³/h |
Initial Pressure Drop Pa |
|---|---|---|---|---|---|---|
| GZ-G3-G-2-M-287-287-48-W | G3 | Coarse 45% | 287 × 287 × 48 | 0,1 | 850 | 70 |
| GZ-G3-G-2-M-287-437-48-W | G3 | Coarse 45% | 287 × 437 × 48 | 0,2 | 1.220 | 70 |
| GZ-G3-G-2-M-287-592-48-W | G3 | Coarse 45% | 287 × 592 × 48 | 0,3 | 1.700 | 70 |
| GZ-G3-G-2-M-437-592-48-W | G3 | Coarse 45% | 437 × 592 × 48 | 0,4 | 2.500 | 70 |
| GZ-G3-G-2-M-490-592-48-W | G3 | Coarse 45% | 490 × 592 × 48 | 0,5 | 2.800 | 70 |
| GZ-G3-G-2-M-592-592-48-W | G3 | Coarse 45% | 592 × 592 × 48 | 0,6 | 3.400 | 70 |
| GZ-G3-G-2-M-287-592-96-W | G3 | Coarse 45% | 287 × 592 × 96 | 0,5 | 1.700 | 45 |
| GZ-G3-G-2-M-592-592-96-W | G3 | Coarse 45% | 592 × 592 × 96 | 0,9 | 3.400 | 45 |
| GZ-G4-G-2-M-287-287-48-W | G4 | Coarse 55% | 287 × 287 × 48 | 0,1 | 850 | 80 |
| GZ-G4-G-2-M-287-437-48-W | G4 | Coarse 55% | 287 × 437 × 48 | 0,2 | 1.220 | 80 |
| GZ-G4-G-2-M-287-592-48-W | G4 | Coarse 55% | 287 × 592 × 48 | 0,3 | 1.700 | 80 |
| GZ-G4-G-2-M-437-592-48-W | G4 | Coarse 55% | 437 × 592 × 48 | 0,4 | 2.500 | 80 |
| GZ-G4-G-2-M-490-592-48-W | G4 | Coarse 55% | 490 × 592 × 48 | 0,5 | 2.800 | 80 |
| GZ-G4-G-2-M-592-592-48-W | G4 | Coarse 55% | 592 × 592 × 48 | 0,6 | 3.400 | 80 |
| GZ-G4-G-2-M-287-592-96-W | G4 | Coarse 55% | 287 × 592 × 96 | 0,5 | 1.700 | 55 |
| GZ-G4-G-2-M-592-592-96-W | G4 | Coarse 55% | 592 × 592 × 96 | 0,9 | 3.400 | 55 |
High-Capacity Models
High-capacity models identified by the letter H in the product code provide a larger filtration area within the same face dimensions.
| Filter Model | EN 779 Withdrawn |
ISO 16890 | Dimensions W × H × D |
Filtration Area m² |
Nominal Airflow m³/h |
Initial Pressure Drop Pa |
|---|---|---|---|---|---|---|
| GZ-G3-G-2-H-287-287-48-W | G3 | Coarse 45% | 287 × 287 × 48 | 0,3 | 850 | 70 |
| GZ-G3-G-2-H-287-437-48-W | G3 | Coarse 45% | 287 × 437 × 48 | 0,5 | 1.220 | 70 |
| GZ-G3-G-2-H-287-592-48-W | G3 | Coarse 45% | 287 × 592 × 48 | 0,6 | 1.700 | 70 |
| GZ-G3-G-2-H-437-592-48-W | G3 | Coarse 45% | 437 × 592 × 48 | 1,0 | 2.500 | 70 |
| GZ-G3-G-2-H-490-592-48-W | G3 | Coarse 45% | 490 × 592 × 48 | 1,1 | 2.800 | 70 |
| GZ-G3-G-2-H-592-592-48-W | G3 | Coarse 45% | 592 × 592 × 48 | 1,2 | 3.400 | 70 |
| GZ-G3-G-2-H-287-592-96-W | G3 | Coarse 45% | 287 × 592 × 96 | 0,8 | 1.700 | 45 |
| GZ-G3-G-2-H-592-592-96-W | G3 | Coarse 45% | 592 × 592 × 96 | 1,7 | 3.400 | 45 |
| GZ-G4-G-2-H-287-287-48-W | G4 | Coarse 55% | 287 × 287 × 48 | 0,3 | 850 | 85 |
| GZ-G4-G-2-H-287-437-48-W | G4 | Coarse 55% | 287 × 437 × 48 | 0,5 | 1.220 | 85 |
| GZ-G4-G-2-H-287-592-48-W | G4 | Coarse 55% | 287 × 592 × 48 | 0,6 | 1.700 | 85 |
| GZ-G4-G-2-H-437-592-48-W | G4 | Coarse 55% | 437 × 592 × 48 | 1,0 | 2.500 | 85 |
| GZ-G4-G-2-H-490-592-48-W | G4 | Coarse 55% | 490 × 592 × 48 | 1,1 | 2.800 | 85 |
| GZ-G4-G-2-H-592-592-48-W | G4 | Coarse 55% | 592 × 592 × 48 | 1,2 | 3.400 | 85 |
| GZ-G4-G-2-H-287-592-96-W | G4 | Coarse 55% | 287 × 592 × 96 | 0,8 | 1.700 | 55 |
| GZ-G4-G-2-H-592-592-96-W | G4 | Coarse 55% | 592 × 592 × 96 | 1,7 | 3.400 | 55 |
Custom dimensions can be manufactured.
Differential pressure tolerance should be evaluated according to whichever value is greater: ±10% + 5 Pa or 10 Pa + 5 Pa.
Standard vs High-Capacity Comparison
M – Standard Capacity
An economical product group with a standard filtration surface area for general HVAC pre-filtration applications.
H – High Capacity
Provides a larger filter surface area within the same face dimensions. As a result, it can help increase dust-holding capacity and service life.
Application Areas
Product Advantages
Filter Selection Criteria
Technical Performance Note
The filtration area, nominal airflow and initial pressure-drop values shown in the tables apply to the specified product dimensions and reference test conditions.
Actual pressure drop and service life can vary according to face velocity, dust load, filter media, number of zig-zag folds, ambient humidity, installation conditions and process conditions.
G3 and G4 are former classifications from the withdrawn EN 779 standard. The ISO 16890 class should therefore be verified according to the tested performance of the relevant product.
Cassette filters are coarse pre-filtration products. Applications requiring fine-particle filtration, HEPA filtration, gas removal or odor control require additional filtration stages.
Get Technical Support for Cassette Filter Selection
Cassette Filter selection should consider filter dimensions, airflow, filter class, capacity type, frame material, gasket configuration and the allowable pressure drop.
Contact Airtes for the selection and supply of standard or custom-sized Cassette Filter (ZIG ZAG) products.
