The convective boiling of refrigerant inside the horizontal smooth tube is a critical process in refrigeration systems. Besides the significant contribution that the vaporization process makes, there is still a phenomenon that causes a decrease in efficiency and some adverse effects during the operation of the system, which is the phenomenon of dryout. In this paper, the dryout phenomenon will be studied, analyzed, and evaluated based on experimental results and correlation models’ modeling. From there, solutions can be proposed to overcome this phenomenon to enhance the efficiency of the convective heat transfer coefficient (CHTC) of the boiling procedure in the tube. Experimental results showed that under evaporation temperature conditions of 5 °C of refrigerant R134a and heat flux of 18 kW/m2 with the mass flux of 333 kg/m2s in a horizontal pipe with 8.92 m inner diameter, the dryout phenomenon occurs at quality x = 0.89, with quality larger than 0.89, and the CHTC decreases quickly. The tube surface temperature is unstable and increases significantly. In addition, analysis results based on correlation models were also performed, with the results showing that Mori’s model and Wojtan’s model gave the most accurate results compared to the experiment.