Question-and-Answer Resource for the Building Energy Modeling Community
 | 1 | initial version |
See this note in the Auxiliary Programs Reference:
The ground temperatures in .epw files are calculated from "a heuristic, time lagged calculation based on dry bulb temperature and location. References on the topic are found in Kusuda (see references)."
References are:
Kusuda, T., “Earth Temperatures Beneath Five Different Surfaces”, Institute for Applied Technology, NBS Report 10-373, 1971, NBS, Washington DC 20234.
Kusuda, T., Least Squares Technique for the Analysis of Periodic Temperatures of the Earth’s Surface Region, NBS Journal of Research, Vol. 71C, Jan-Mar. 1967, pp 43-50.
I was able to find .pdfs of both Kusuda documents with a google search.
