Abstract: A novel green manufacturing process for medium and high-density fiberboard (MDF and HDF) production is disclosed, where the green manufacturing process refers to a novel low-emitting manufacture of MDF and HDF in terms of HAP emission. The novel manufacturing process comprises a preconditioning unit operation for raw wood furnish material, where blends comprising two or more woody materials having disparate moisture contents are held in a preconditioning vessel for up to 48 hours under controlled temperature conditions, where the moisture content is homogenized to produce a blend having substantially uniform moisture content. The blend is preconditioned in the novel manufacturing process to facilitate moisture homogenization kinetics, and to uniformly increase the material temperature above the lignin glass transition temperature. Subsequent process steps, such as defibration and fiber drying, require lower temperatures to produce and dry wood fiber, thus lowering HAPs emission.