Estimating Air-Drying Moisture Content Losses for Red Oak and Yellow-Poplar Lumber

Air-drying below an optimum moisture content (MC) results in excessive costs as a result of both increased inventory expenses and loss of quality. Industry has found it impractical to obtain MC readings of air-drying lumber on a regular basis. An accurate means of estimating daily MC loss is described from which regional air-drying calendars can be developed. A study was done where drying samples were exposed to the environmental conditions in three air-drying yards over 5 months. The daily rate of moisture loss was then related to meteorological variables obtained from a regional weather station. The equation developed for four-quarter yellow-poplar lumber below 80 percent MC was: MCLOSS = -2.00 0.153(MC) 0.056(TEMP) – 0.062(RH) where: MCLOSS = daily MC loss, MC = MC at the beginning of the air-drying day, TEMP = average daily temperature, and RH = average daily relative humidity.

You must be logged in to download any documents. Please login (login accounts are free) or learn how to Become a Member