In this study, a performance experiment was conducted on the feedwater conditions of a polyvinylidene fluoride hollow-fiber vacuum membrane distillation (VMD) module prior to construction of a VMD seawater desalination demonstration plant in South Korea that will have a capacity of 400 m³/d. The VMD module, manufactured by Econity Co., Ltd., South Korea, has an effective area of 5.3 m². For the performance test of the hollow-fiber VMD module, a laboratory-scale VMD system was built and the tests were conducted under various feedwater conditions. The results showed that under feed conditions of 75°C, 8 m³/h feedwater flow rate, and salinity of 35,000 ppm, permeate flux was up to 18 LMH and salt rejection was up to 99.99%. [ABSTRACT FROM AUTHOR]