Design and Tests of a Solar- Dehumidifier Kiln with Heat Storage and Heat Recovery Systems.
A rockbed heat storage unit, an additional solar collector, and a heatpipe heat recovery system were added to an existing experimental solar-dehumidifier kiln and tested with 4/4 yellow-poplar. This novel system kiln-dried and conditioned yellow-poplar lumber from green (92%) to 8 percent moisture content in 7 to 11 days throughout the year. These drying times are almost equal to the conventional steam-heated kiln-drying time of 6 to 10 days. Lumber quality was excellent. The lumber was lighter in color than conventional kiln-dried lumber. No collapse, surface checking, or end checking was observed in the dried lumber. Adding heat storage and heat recovery systems and a second solar collector to the solar-dehumidifier kiln increased the kiln's energy efficiency by nearly 30 percent. A solar-dehumidifier kiln, with heat storage and heat recovery systems and an additional collector, offers an energy-efficient method of drying hardwood lumber.
Forest Products Journal
Chen, P. Y. S. & Helmer, W. A. (1987). Design and tests of a solar- dehumidifier kiln with heat storage and heat recovery systems. Forest Products Journal 37(5): 26-30.