Patent ID: 6849100

Claim:
An apparatus for providing fresh air to a clean room, comprising: a fresh air duct having a first portion configured to direct fresh air from an input of the fresh air duct to an output of the first portion; and a second portion releaseably coupled to the output of the first portion and configured to direct fresh air from the output of the first portion along a pathway through the second portion, the fresh air duct including an outlet portion downstream from the second portion, the fresh air duct configured to direct fresh air filtered by an air conditioning system towards a clean room downstream from the fresh air duct, the fresh air having a first level of particle density; a first detachable filter comprising a separate particle filter in the second portion of the fresh air duct, downstream from the air conditioning system and upstream from the clean room, configured to further filter the fresh air to provide filtered fresh air having a second level of particle density therein that is less than the first level; and a second detachable filter in the outlet portion of the fresh air duct configured to provide filtered air downstream of the second detachable filter to the clean room.