Fan Filter Unit Package Assemblies (FFUPAs) for large clean zones I.E. the (“Primary”/”Secondary” FFU set)
Typically FFUs are not made over 12 square feet in size due to ergonomic restrictions, as well as the practicality of packaging and shipping the completed product. Additionally, there are some practical complications in making a single HEPA/ULPA/PTFE filter over 72” in length. When a tool has a clean environment that is being designed to operate as a single “zone” with a goal of identical pressure or flow throughout, we use a “Primary”/”Secondary” approach. The “Primary” FFU” has the speed control or pressure control , and powers the lights and ionizers, if required. Meanwhile the “Secondary” FFU(s) gets its/their control from the “Primary FFU”. In this way a very large clean zone can be controlled from a single point on the “Primary FFU”. See the speed control/pressure control section for details on the methods of controlling the “Primary” FFU, and thereby the entire zone.