Ejectors are widely used in applications where deeper vacuum levels are required. They are highly reliable due to the absence of moving parts. The performance of an ejector depends on several components, the critical factor being flow channel configuration or arrangement. An extensive search on the design of thermal compressors is performed in this paper to select a better suction rate based on the design of the thermal compressor. The performance is measured by the suction (secondary) flow rate of the primary steam jet from a low-pressure vapor plenum. Numerical simulation is implemented to investigate the thermal flow behavior of the steam ejector. Out of the selected design, 1539% is the best jet flow rate without any flow channel, while some designs can only produce 13% of the jet flow. With flow channel implementation the flow rate decreases while the effects of temperature are the same. The finalized design has proved the impact of temperature on the suction rate in selected 9 plus designs.