This paper describes the development of a second generation of hourly weather files for energy calculations, WYEC2, which represents a significant improvement over the original set of WYEC (weather year for energy calculations) files developed by ASHRAE more than 25 years ago. The paper discusses both the process and rationale for WYEC2 development and describes a CD, separately available from ASHRAE, that contains the WYEC2 hourly weather files along with a User's Manual and Toolkit to aid in their use and application. The WYEC files contain data on 58 U.S. and Canadian cities. Development of the files and software was sponsored by ASHRAE Technical Committee 4.2, Weather Information.

Units: Dual