This Recommended Practice (RP), IEST-RP-CC012.4, makes recommendations regarding factors to consider in the design of cleanroom facilities. The RP is limited to those environmental conditions that typically confront cleanroom designers and users. The RP is intended to provide users with a means to establish performance criteria for cleanrooms.

Abstract of Key Revision Areas for RP-12.4

What is Improved

  • Enhanced description about the “Integrity of Building Envelope and Interstitial Spaces to Prevent Insects/Pests Entry” in Section 4.3.12.
  • Improved description on “Process-specific airflow patterns”.
  • Revised language on “Wireless sensor”.
  • Detail discussions about dedicated space for storing cleaning equipment, water for cleaning and waste drain, etc. were added for the “Design considerations for controlling contamination” in Section 5.9.1.
  • Improved and more detail discussions on “Optimization of workflow/paths in existing cleanroom spaces”, “Design for facility disinfection” and “CFD” analysis.

What is New

  • Added discussion on “Impacts to building pressurization control”.
  • Added detail diagrams for 4 categories of airlocks: Cascading, sink, bubble and dual-compartment.
  • Added “Design considerations for cleanroom entry and exit for personnel”.
  • Added new discussion section on “Room pressurization strategy”.
  • Detail discussion about grounding connections for wrist strap, footwear, work surfaces, metal walls and ceiling grids to avoid charging and ESD, impacts by RFI generator and ionizers, etc. were added in the “Grounding systems” in Section 5.16.
  • Added more discussion on “Airflow turn-down and reset” to reflect new ISO 14644-4 (2022) standard.
  • Added discussion section for “Cleanroom enclosure airtightness”.
  • Added discussion on “Demand based airflow control” to reflect ISO 14644-4 (2022).
  • In the Appendix C of “Cleanroom Modeling Approach”, a new terminology called “contaminant removal effectiveness” was added to reflect the new 14644-4 (2022) and 14644-16 (2019) modeling equations, this correctional factor can increase the predictability in estimation and calculation airflow rate.
  • New discussion about ground filters, personnel grounding plan, ESD tester, etc. were added into the “Grounding systems” in Section 5.16.
  • Many new references (articles, books and standards) were added in the Bibliography of Appendix E.

Supersedes previous versions of RP-CC012

Considerations in Cleanroom Design was prepared by Working Group 012 of the IEST Contamination Control Division (WG-CC012).