I am using the guidelines established by the CDA. As indicated in the FPN, the CDA guidelines utilize the average of the 2% ASHRAE design temperatures for each region and major city in the state.
The guildelines and sliding scale card can be obtained FREE from
www.copper.org_________________________
Bryan P. Holland, ICC Electrical Code Official
CBO, Plans Examiner, Inspector, Instructor
Secretary - IAEI Florida Gulf Coast Division
Secretary - BOAF Gulf Coast Chapter