We have a wood drying kiln. Dh found a Nyle L200 used from a guy that used it once before going through a divorce. Got the kiln and 3000 bf of red oak 2 x 4's that are making our wood floor for $2000.
We then built the building that becomes the kiln to hold the wood (a well insulated 10 x 16). The Nyle L200 is like a reverse heat pump that sits inside and removes the moisture in the wood. Huge fans in the kiln building keep the air moving through the stickered wood so that the drying process is even. The red oak for our floors sat in a covered carport for 2 years. You would think that the moisture content would be near 20% at that point, and in some parts it was, but alas it was nearly 80% still in parts of the wood towards the center. After 3 weeks in the kiln (running 24 hrs a day), Dh got the moisture content down to 10% throughout the boards---evenly. At the beginning of the drying process, we were getting 20 gallons of water out a day. Towards the end, that was reduced to 5 gallons or less in a day.
If you down your trees, paint the ends with a special sealer that you can purchase from NYLE. This keeps the ends from drying too fast and keeps the wood from splitting. If you have ever looked at the ends of oak firewood before splitting it, you know what I mean.
Gene Wengert is acknowledged as one of the most knowledgable guys in the US on drying wood. He gives seminars in Memphis several times a year. Dh went to one of his seminars and said it was worth every penny. Also, go to
www.woodweb.com and
www.sawmillingmag.com for some additional info.