1.HF Vacuum Dryer 2.All kinds of wood 3.Faster and ... need boiler No polution. 2. ThoeryHF and Vacuum condition:As HF heats from inside, so the core of wood will dry ... the surface and leave permanent defect on the wood, but HF vacuum condition will totally eliminate the problem.3. Temperature control ... very sensitive on the temperature, this is a big advantage. HF Vacuum Dryer (3CBM)