Unclassified 



SECURITY CLASSIFICATION OF THIS PAGEfWhe, 



20. Continued 



copper fin exchangers coated with any of the three different coating systems were superior in 

 thermal efficiency to the uncoated units. The opposite was true for the all aluminum units 

 and for the copper tube/aluminum fin units. Based on 1978 prices, coating of copper tube/ 

 copper fin exchangers increases their cost from 48 to 60%. It is believed this can be justified 

 on the basis of increased life expectancy alone. 



Library Card 



Civil Engineering Laboratory 



PERFORMANCE OF UNCOATED AND COATED NON- 

 FERROUS HEAT EXCHANGERS IN A TEMPERATE 

 MARINE ENVIRONMENT FOR TWO YEARS (Final), by 

 T. Roe, Jr., J. F. Jenkins, and R. L. Alumbaugh, Ph D 

 TN-1560 61ppillus August 1979 Unclassified 



1. Protective coatings 2. Heat exchangers I. YF53. 534.006. 01. 040 



Twelve finned tube heat exchangers — four pieces of three different materials or material 

 combinations — were operated in a marine environment (1) uncoated, (2) coated with an electro- 

 statically applied polyester enamel, (3) coated with a specification alkyd system, or (4) coated 

 with a zinc inorganic silicate material. Temperature drops across each exchanger were monitored 

 for 24 months and heat transfer capacities were calculated for selected periods. Copper tube/ 

 copper fin exchangers coated with any of the three different coating systems were superior in 

 thermal efficiency to the uncoated units. The opposite was true for the all aluminum units and 

 for the copper tube/aluminum fin units. Based on 1978 prices, coating of copper tube/copper fin 

 exchangers increases their cost from 48 to 60%. It is believed this can be justified on the basis of 

 increased life expectancy alone. 



Unclassified 



' CLASSIFICATION OF 



