Commercial-scale RF/V drying of softwood lumber. Part 3. Energy consumption and economics

This paper addresses the capital and operating cost requirements for commercial size radio frequency/vacuum (RF/V) kiln installations of various power densities and radio frequency amplifier sizes for the drying of softwood lumber. Furthermore, a feasibility study of future commercial RF/V kilns is carried out. Generally, it is concluded that RF/V drying costs are more competitive than conventional kilns for lumber 101 mm and thicker, with at least a 15 to 25 percent cost advantage depending upon species and grades. Thinner sections of high-grade softwood lumber can likely be RF/V dried more competitively, particularly if the costs can be recovered with a higher lumber sales value in the marketplace.