Biofilter cover

摘要

The invention concerns an open biofilter (1) with a cover (4) made of a laminate comprising at least one microporous functional layer and a carrier layer to which the functional layer is secured. The functional layer can be an expanded polytetrafluoroethylene membrane and the carrier layer can be applied to both sides of the functional layer. The functional layer or the laminate is permeable to gas or air and impermeable to water, such that all the outgoing air from the biofilter can pass through the laminate whilst the moisture is retained in the biofilter.