The use of occupancy as a surrogate for particle concentrations in recirculating, zoned cleanrooms

摘要

The substantial energy demands or today s cleanroom environmental-maintenance systems provide large opportunities for energy conservation. However, cleanroom environments are subject to much more stringent standards and operate with much smaller tolerances, and therefore simple application of industrial/commercial controls is not sufficient. We conducted a set of measurements in a Class 1000 cleanroom to confirm that humans are the predominant source of particles in a cleanroom, supporting that occupancy can be used as an effective surrogate for particle concentrations. Our data suggest that people release approximately 1.7 x 104 particles per minute into the cleanroom and raise the local concentration of particles by 1742 ±481 particles m~3 person'. Furthermore, our timescale analysis on control system and ventilation unit responses indicates that a predictive-occupancy system is required for implementing demand-controlled ventilation.