Ideal Humidity

[Rick Gooden]

Anyone know what the ideal humidity for a ww shop would be. Here in the Ohio Valley it gets really humid in the summer, but air conditioner in the shop seems to keep it under control. During the winter it can get quite dry (in comparison) with the heater going. I can control that with a humidifier. Just wondering at what % I should try to keep it.

[Joe Chritz]

I missed this earlier.

I believe that sawmills and kilns attempt to reach 38% RH.

Here is a rough chart for RH to MC. Changes in temp effect the RH a decent amount.

58-64 RH -11%
52-58 RH -10%MC
46-52 RH - 9% MC
39 -46 RH - 8% MC
32 -39 RH - 7% MC
25 -32 RH - 6% MC
19-25 RH - 5% MC

Woodweb has a commercial drying forum that has enough info on humidity and drying lumber to make ones head hurt.

Joe