Class 100 clean room ducting length

[Srinath]

what is the maximum length of the ducting that can be run from Air Handling Unit  to class 100 clean room. Please suggest the permissible length to achieve the above clean conditions. While designing for one of the projects, i want to locate the Air Handling Unit at a distance of 100 meters from the class 100 clean room. Will it pose any problems during maintenance/designing. Any suggestions / design parameters to be considered may please be suggested.