The invention relates to a device for filtering contaminants, such as
particulates and vapor phase contaminants, from a confined environment
such as electronic or optical devices susceptible to contamination (e.g.
computer disk drives) by improving performance and possibly incorporating
multiple filtration functions into a unitary filter. The filter includes
flow layers which improve filter performance. Filtration functions
include a passive adsorbent assembly and can include a combination of
inlet, or breather filter and adsorbent filter. Moreover, recirculation
filter, diffusion tube and outside mount functions can be added to the
filter depending on desired functionality within the enclosure.