Replacement filters fail for boring reasons: a frame that is 6 mm too deep, a gasket on the wrong face, or an efficiency class that does not match the validation protocol. This checklist covers what to confirm before a batch is ordered.
Measure the installed filter, not the catalogue
- Record the actual frame width, height and depth of a removed filter, or of the housing opening if no filter is available. Nominal sizes such as 610 × 610 mm hide real differences between makers.
- Note the frame material (aluminium extrusion, galvanised steel, stainless steel or MDF) and whether the frame has a flange or a knife-edge channel.
- Photograph the label of the installed filter. It usually shows the maker’s code, the rated airflow and the test date.
Confirm the sealing method
- Gasket seal: state which face carries the gasket (upstream, downstream or both) and the gasket material.
- Gel seal: state the knife-edge width and the position of the gel channel. Gel-seal frames are not interchangeable with gasket frames.
Confirm performance
- Efficiency class to the standard the site uses, for example H13 or H14 to EN 1822, or the equivalent your protocol references.
- Rated airflow and the initial pressure drop the housing or fan filter unit was balanced for. A filter with a higher pressure drop at the same airflow can push a fan filter unit outside its operating range.
- Whether individual test documentation per filter is required by the site’s validation procedure, or a batch certificate is acceptable.
Plan the batch and the handling
- Quantity per size and the replacement cycle, so that the batch can be packed and shipped as one consignment.
- Storage conditions on site: filters should stay in their cartons, upright, dry and away from forklift traffic until installation.
- Who installs the filters and who carries out the post-installation leak test.
What a complete request looks like
40 × HEPA panel filters for existing FFU housings, measured frame 1170 × 570 × 69 mm, aluminium frame, gel seal, H14 to EN 1822, 1,000 m³/h rated airflow, batch certificate acceptable, destination country named on the order, installation and leak test by our service contractor.
Filters are quoted per batch with their test documentation and packing data. Single urgent pieces are quoted only when a matching configuration already exists.