May 16, 2014 · NOTE: All documents linked from this page are in PDF-format. Interpretation 170-2013-1 – May 16, 2014 (Refers to the requirements in ANSI/ASHRAE/ASHE Standard 170-2013, Section 6 and Table 6.7.2, regarding “Operating room, procedures rooms (all class A, B, and C surgeries)” requirements for primary supply diffusers and additional supply diffusers.)