International Weather for Energy Calculations (IWEC) contains "typical" weather files, suitable for use with building energy simulation programs, for 3,012 locations outside the USA and Canada. The files are derived from Integrated Surface Hourly (ISH) weather data originally archived at the National Climatic Data Center.
For these selected locations, the ISH database contains weather observations on average at least four times per day of wind speed and direction, sky cover, visibility, ceiling height, dry-bulb temperature, dew-point temperature, atmospheric pressure, liquid precipitation, and present weather for at least 12 years of record up to 25 years. Because the ISH database contains no measured solar radiation, the hourly total horizontal solar radiation is calculated using an empirical model based on the sun-earth geometry, reported cloud cover, temperature difference from three hours previously, relative humidity, and wind speed.
A second empirical model is used to calculate direct normal solar radiation based on the solar angle and the ratio of the derived total global horizontal compared to the extraterrestrial solar radiation. Other models then use these derived solar radiation values to calculate various illuminances (global horizontal, direct normal, diffuse horizontal) and zenith luminance that are useful for daylighting studies.
$229 (ASHRAE Member $199) / 2012 / CD
This DVD contains the results from ASHRAE Research Project RP-1477, "Development of 3012 Typical Year Weather Files for International Locations," developed by White Box Technologies, Moraga, California, Y. Joe Huang, Principal Investigator.