Use dehumidifier to dry wood questions

Re: FPL-GTR-57, etc.

William Duffield

It depends.

On the temperature, the humidity, the thickness of your wood, it's current moisture content, rate of air movement, species and quantity of wood. The USDA FPL has published extensive drying instructions and charts specifying all these parameters, and the time to hold the boards at each temperature before moving on to the next stage. You might start with a Google search for:

usda fpl drying schedule

My mentor did this with Yellow pine

Jim Matthews

Using a dehumidifier (with external condensate pan) and a 5 Mil plastic vapor barrier he could dry 8/4 stock from the local sawmill to less than 10% humidity in about ten days.

The volume the household dehumidifier could manage was the simple of a workbench -

3x4x8 feet.

It was prohibitively expensive compared to kiln dried, based on his electric bill - but was necessary because he needed lumber for a time sensitive order.

Results were adequate, but the topmost boards tended to take on wind.

****

Will it help? Yes - if the space is sealed and small enough.

Will it speed up the process? Yes - but electricity costs may be considerable.

Will it produce better results? Yes - if you seal all board ends, stack carefully and turn the stack more than once.

Oak is not easy to dry

Bill Tindall, E.Tn.

If you dry oak too fast you can get massive drying defects. My advice would be to not rush it unless you know how fast oak can be safely dried and have some means of monitoring and controlling.