Moisture, shrinkage, density and kiln-drying equations.
SVP = 0.6108 x exp( (17.27 x T) / (T + 237.3) ) T in deg C, result kPaGreen weight = Oven-dry mass x (1 + Green_MC/100)Water to remove = Weight_current - Weight_targetBasic density = oven-dry mass / green volume (kg/m3)MC% = (Wet weight - Oven-dry weight) / Oven-dry weight x 100Drying rate = (Previous MC - Current MC) / Days elapsedDays to target = (Current MC - Target MC) / Drying rateProgress % = (Start - Current) / (Start - Target) x 100Drying time ~ k x Thickness^2 x severity_factor x ln(MC1/MC2)Schedule steps decrease wet-bulb (raise temp) as MC dropsTarget EMC at each step is set ~2-4% below current wood MCwhere S_total = radial or tangential total shrinkage coefficientVolumetric ~ Radial% + Tangential% (small-strain approximation)T/R ratio = Tangential / Radial (warp risk: under 1.5 stable, over 2.0 high)EMC = (1800/W) x [kh/(1-kh) + (k1kh + 2k1k2k^2h^2)/(1 + k1kh + k1k2k^2h^2)]Target EMC from room T and RH (Hailwood-Horrobin)Acclimation days ~ base x thickness_factor x gap_factor x airflow_factorThicker boards and poor airflow increase the time sharplyMC from mass = (Wet mass - Oven-dry mass) / Oven-dry mass x 100FSP temperature adjust = FSP_20 - 0.1 x (T - 20) (T in deg C)Free water (above FSP) = max(0, MC - FSP)