Spruce belongs to most easily dried wood species, but nevertheless, larger number of cracks occurs in it, particularly in cold winter days, reducing the quality of dried wood. To find out factors causing worse quality in autumn and winter milder and sharper drying conditions were executed in a pilot experimental drying chamber. The quality of sawed wood was evaluated on fresh material, and followed to dry on target moisture of 10 %. Final control of quality of drying was assessed by designation of the achieved final moisture, moisture gradient, number and size of cracks and degree of warp and casehardening. Drying the spruce with sharper conditions showed as more risked, because a larger number of cracks occurred, so as larger moisture gradients and casehardening. In winter, after drying on high temperatures, unless the hot wood is adequately cooled, additional cracks can emerge.
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