scope:

FOREWORD

Addendum a revises the definition of the moisture-design reference year in Sections 3.1 and 4.5 as indicated and adds a related evaluation criterion in Section 6. Since publication of Standard 160, ASHRAE Research Project 1325-RP, "Environmental Weather Loads for Hygrothermal Analysis and Design of Buildings," was completed. This research project analyzed several existing weather year selection methods, including the tenth-percentile warm and cold years currently used by Standard 160, and showed that the existing methods were not successful in correctly ranking the severity of weather years for hygrothermal analysis. The project developed a new method of ranking weather years that was found to be consistently successful. This addendum will bring the standard in line with these research results, incorporating the new weather years and removing the old.

Note: In this addendum, changes to the current standard are indicated in the text by underlining (for additions) and (for deletions) unless the instructions specifically mention some other means of indicating the changes.