Condensation heat transfer models of refrigerant outside horizontal low-finned tubes were surveyed.Thermodynamic properties of carbon dioxide were present.Surface tension effects on condensate retention angle and condensation heat transfer coefficient of carbon dioxide were studied.Effects of fin density and size upon fin efficiency

retention angle

condensation heat transfer coefficient

and heat transfer enhancement ratio were analyzed.Optimum fin size and heat transfer enhancement ratio were obtained.The generated results for a finned tube with a root diameter of 20 mm is that optimum fin density is 435 fins per meter

optimum fin height is 5.1 mm

and optimum fin pitch is 2.3 mm.