A filter section, or filter box, is used in an air transport system to clean air and/or to keep it clean.
Material quality and thicknesses
For normal comfort ventilation, filter sections are manufactured from the following materials:
- Casing: Sendzimir galvanised steel;
- Filter: compact, panel, or bag filter; available in different filter classes, suchas G3, G4, M5, M6, F7, F8, and F9;
- Other choice of material, depending on the application, in consultationwith the supplier.
The filter section is available with circular and rectangular connections.
The available nominal dimensions of the intermediate filter sections are standardised according to NEN-EN 1505 (rectangular connections) and NEN-EN 1506 (circular connections) and can be selected as indicated in the tables for standard dimensions, as referred to in this guide in sections 220.127.116.11 (rectangular connections) and 18.104.22.168 (circular connections). They refer to internal dimensions with a tolerance of +0 to -5 mm. The dimensions depend on the manufacture.
It must always be possible to inspect intermediate filter sectionsfor contamination. Therefore, when installed, there must be a possibility to easily remove, check and replace the filter. For this purpose the filter section must be equipped with a removable inspection cover. This cover is attached to the housing in an airtight manner.
Filter sections must be fitted in accordance with the manufacturer's instructions. If present, they must at least comply with the requirements of paragraph 3.1.4.
Filter sections with circular connections can be connected to the air ducts more efficiently than filter sections with rectangular connections and contribute to the airtightness of the air duct system, if these fittings possess sufficient airtightness in accordance with NEN-EN 15727.