The desalting of seawater has been a vital issue in several countries around the world in which water shortage is a serious problem. Through the process of designing desalination systems, with consideration of energy crisis, amount of energy consumption is a very important economical factor. In multi-effect distillation systems with thermal vapor compression (MED-TVC), thermo-compressor plays a main role in energy consumption. The geometry and operating conditions of thermo-compressor can have a significant influence on energy consumption. In this research, the influence of changing the suction position of thermo-compressor on the amount of energy consumption of the plant is analyzed. Results of the study showed that variation in suction pressure of thermo-compressor has considerable effects on the entrainment ratio. However, in order to have the maximum entrainment ratio and consequently reduce energy consumption, integration of MED-TVC with MED desalination must be optimized into the position of thermo-compressor suction. It was found that changing the suction location of thermo-compressor from the last effect to the middle effects or increasing the suction pressure has a valuable role in decreasing the energy consumption of the system. Results showed that the optimum value of compression ratio of thermo-compressor is between 2 and 2.5. (C) 2011 Elsevier B.V. All rights reserved.