NY-14-029 -- Development of 3,012 IWEC2 Weather Files for International Locations (RP-1477) ✓ Most Recent

This paper is based on findings resulting from ASHRAE Research Project RP-1477.

This paper announces the completion of a large new data set of International Weather for Energy Calculations 2 (IWEC2), i.e., typical year, weather files for 3012 locations outside of the U.S. and Canada and describes the procedures used to produce these weather files, including how the raw weather data from the Integrated Surface Hourly (ISH) database were processed and how missing records and unrecorded climate parameters have been derived.Particular attentionwas paid to the derivation of global horizontal and direct normal solar radiation using a combination of empirical and analytical solar models. The procedure used to select the typical months making up the IWEC2 files from the historical weather record. is also explained. These IWEC2 weather files are then compared to other sources of international weather data and to an earlier, smaller set ofIWECweather files developed in 2001. TheIWEC2weather files are found to have very similar heating degree days, and slightly more cooling degree-days than the IWEC. There is substantially more variation in the solar radiation, with the IWEC2 weather files having somewhat less total and somewhat more direct normal solar radiation than theearlier IWEC weather files.