Drying via vacuum actually produces steam.
Water boils at a lower temperature under vacuum.
So @ -200mbar water boils @ 61.5 Deg C.
each litre of water extracted from the wood, produces about 800 litres of steam that is extracted and condensed back into water.
We are having tests done on the extracted water to see if any extractives are carried over with the condensate from the wood.
Any one want some wood alcohol. :D