RECOMMENDATIONS FOR MOISTURE CONTROL in buildings should be based on the specific climatic conditions that the building experiences or will experience. In Chapter 23, “Thermal and Moisture Control in Insulated Assemblies-Applications,” in the 1997 ASHRAE handbook [1], three climate types are delineated for the purposes of moisture control: heating, cooling, and mixed climates. However, the definitions of these climate types are somewhat arbitrary, and they are used only to formulate a set of prescriptive and generic moisture control strategies. Neither the definition of climate type nor the moisture control strategies in the 1997 ASHRAE handbook are supported by analyses of the performance of buildings under design weather conditions and under standard indoor moisture design loads. At present, a standard for such moisture design loads is under development within ASHRAE (SPC 160P-Design Criteria for Moisture Control in Buildings). It will include criteria for moisture design weather data but will not provide the actual weather data. Until such design weather data are available, a moisture analysis has to be conducted with currently available weather data or design weather data generated by the user.