Developing and evaluating continuously changing schedules for Hardwood lumber dry kilns

Two methods for designing continuously changing hardwood dry kiln schedules were developed. A continuously changing mini step drying schedule for 4/4 red oak was successfully designed and adapted to a micro computer. The demonstration trials were successfully completed. Comparison with a conventional step schedule trial shows the designed midpoint schedule performed as expected taking 11 percent longer but using 5.1 percent less energy. A second method for designing continuously changing hardwood dry kiln schedules using equations was developed. Equations using percent moisture content to predict dry bulb or wet bulb depression temperatures were found for 8 dry bulb and 9 wet bulb depression schedules. An evaluation of continuously changing hardwood dry kiln schedules indicates an estimated 6.5 percent savings in energy. Energy and time savings result in a 3.8 year pay back period for the investment of computer equipment.