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Humidity in Attics -- Sources and Control Methods

Conference ·
OSTI ID:893037

Guidelines for the control of moisture in attics are in a state of flux. The 1981 ASHRAE Handbook of Fundamentals gives only ''Past Practice'', and notes that such practice might not be currently valid. Furthermore, in the past it was assumed that the attic was an inert structure on which moisture would either condense or pass through unaffected. Results are presented which show that the attic is in a constant state of flux, absorbing and releasing moisture. A mathematical model for predicting the moisture content of attic wood members is presented. The model is used to predict hour-by-hour attic air humidity ratio, and seasonal wood moisture content. Results are compared with measured data. The application of the model to the re-calculation of attic ventilation standards is discussed, both with respect to condensation and wood rot.

Research Organization:
Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
Sponsoring Organization:
USDOE Director, Office of Science
DOE Contract Number:
DE-AC02-05CH11231
OSTI ID:
893037
Report Number(s):
LBL-17590; TRN: US200625%%68
Resource Relation:
Conference: 1984 American Society for an Energy EFficientEconomy Summer Study of Energy Efficiency in Buildings, Santa Cruz, CA,08/14-22, 1984
Country of Publication:
United States
Language:
English