EN 13053 Normative

Air treatment ventilation.  Filters installed in air treatment units.

The first filtration stage must be placed on the air inlet side, as near as possible to the opening for the outdoor air inlet, so as to keep the air treatment elements as clean as possible. Additional pre-filters G1 to G4 are authorised. The second filtration stage is placed on the outlet side at the start of the air supply duct to keep it clean.

When just one filtration stage is used for the supply system, the minimum that must be installed is a class F7 filter.

In the case of using a two filtration stages, the air supply fan must be placed between the first and second filtration stages. With the aim of preventing the development of microbes in the second stage air filters or in a superior stage, the relative humidity in the filter zone must be limited to 90%; temperatures below the dew point temperature must always be avoided. The air filters must not be placed immediately after refrigeration batteries with dehumidification or after humidifiers (exception –steam humidifiers).

If bag filters are used then the filtration zone must be at least 10 m² per 1 m² of the equipment transversal section. The joins used must be of a closed cell type, they must not absorb humidity and they must not form a nutritive substrate for micro-organisms. Permanent fixing for the sealing must be guaranteed (for example, operation from the dirty air side). Filtration sections from an inside height of 1,6 m must be set up with an inspection window (with a minimum interior diameter of 150 mm)  and light inside.

In the fan section, for the purposes of setting the pressure drop value in the filter on designing the air flow, this must be the average of the initial and final drops for clean and dust filled filters respectively.

Note 1 : The volumetric flow variation of air due to dust accumulation must be indicated in the technical specifications. If the specific tolerances for an application are not mentioned, <>10% is acceptable based on the average pressure drop.

The pressure drop in a filter section that is filled with solid particles must not exceed the values given in table 9. Lower pressure drops can also be specified when appropriate.

The filters installed in air treatment units used for human occupation must be tested and classified in accordance with the EN 779 Norm.

Maximum final pressure drop for filters

Class of filter Final pressure drop

G1 - G4

M5 - F7

F8 - F9

150 Pa

200 Pa


Note 2 : the final pressure drops indicated in the table for energy saving reasons are typical maximum values for working air treatment units and lower than those used in the  EN 779 Norm for classification purposes, and the performances obtained in the trials in accordance with the EN 779 Norm are not necessarily fulfilled with these lower pressure drops.

The following data must be shown in a clearly visible way (with a label) in the filter section: class of filter, type of filtering media, final pressure drop. On changing the filter the user must verify and update this information.