Home dehumidifier for drying lumber

Can a home dehumidifier be used to kiln dry lumber? January 31, 2001

Can a home dehumidifier be used to kiln dry lumber after the wood has been shed dried for several months? To minimize corrosion of the unit, is there a starting moisture content level at which it is less likely to corrode the dehumidifier?

Forum Responses
You can use a home dehumidification unit, but times are longer than with commercial units and deterioration is likely at almost any MC. Remember that a 50 pint DH unit will remove about 1% MC from lumber per day if the lumber will release its MC fast enough.

Gene Wengert, forum technical advisor

Would hot lights in an insulated box accelerate that?

I have been told that the chemicals in some woods will eat the coils of a home DH quickly.

I think that with a home DH unit, you will not have as good of a control system. You may have some fire hazards, especially with hot lights. In fact, if you do this in your home, I wonder if your homeowner's insurance would cover you if you had a fire.

Gene Wengert, forum technical advisor

Home dehumidifiers can work but they are designed for operation to about 45-50% RH, which is not low enough for 6% lumber. The components are not designed to last in an acidic atmosphere and they are designed to work at temperatures below 100 degrees F. We have had scores of customers over the years who ate a pile of home dehumidifiers before giving in and buying a real system.

I have a homebuilt kiln that does exactly what you are talking about and I use an old window air conditioner as the heater and dryer. I do keep a small, portable dehumidifier in the kiln to keep the relative humidity down after I dry it so the wood stays in the 8% range until I use it.