Usinga quasi-heat-pulse method to determine heat and moisture transfer propertiesfor porous orthotropic wood products or cellular solid materials

Understanding heat and moisture transfer in a wood specimen as used in the K-tester has led to an unconventional numerical solution and intriguing protocol to deriving the transfer properties. Laplace transform solutions of Luikov's differential equations are derived for one-dimensional heat and moisture transfer in porous hygroscopic orthotropic materials and for a gradual finite heat pulse applied to both surfaces of a flat slab. The K-tester 637 (Lasercomp) supplies a quasi-heat-pulse to both sides of a 2-ft-square specimen and records precise signals as function of time from surface thermocouples and heat flux thermopiles. We obtained transfer properties for moist and oven-dried redwood lumber flooring.