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Drying hardwood is an essential part of lumber processing. Traditionally, manufacturers have used forced heat kilns for drying lumber. 

While traditional kilns get the job done, they are not always the best option. Vacuum-kiln drying offers the advantages of speed, gentleness and higher lumber end-quality.

The Process

Vacuum kiln drying creates more refined, straighter, flatter lumber; less stressed lumber, and better color retention. The Vacuum Dryer operates a vacuum to lower the temperature at which water boils (vaporizes). Wood becomes stronger at a lower temperature. By drying at a low temperature we can accelerate the drying time without harming the wood. Vacuum pressure also sucks the water from the core to the exterior, which is particularly handy for thicker dimensions.

The Tools

At C3 Forest Products we look for the best of the best when it comes to purchasing equipment for our shop. We were immediately impressed with the iDRY system and know that you will be too. iDry models provide fast, reliable and efficient drying, using a combination of heat and vacuum. We use the iDRY PLUS model which dries wood about 5-10 times faster than conventional kilns, and doesn't damage the wood like other traditional methods may.

About the IDry Plus

The iDRY PLUS, which is the model that we use here at C3 Forest Products, dries the same as the traditional size iDRY. This kiln uses airflow to dry a stickered pile similar to a DH kiln or conventional kiln, but under a vacuum pressure equivalent to that on top of Mt Everest; making this a fast and nice drying system.

The pressure applied to the top of the lumber can be as high as 1,600 pounds per square foot and is sustained even while the lumber is cooling after the final moisture content has been reached. The by-product is very flat and linear lumber, free from any cupping, twisting and bowing. Heating the lumber is required to circulate water within the wood and bring it to the exterior so that it can be evaporated as steam, which either condenses on the cool walls of the pressure chamber and runs to drain or is pulled out of the pressure chamber by the vacuum pump as steam. 


Have questions? Feel free to contact us today to talk to a member of our team or to get started on a project.