HOW CAN I CALCULATE THE SAME? ONE WAY IS SU = K .D.L K = FACTOR DEPENDS ON NO. OF COOLER TUBES D = DIA. OF TUBE L = LENGTH OF TUBE I HAVE 10 COOLER TUBES EACH 1.5 M DIA , 12.2 M LONG & TAKING K= 26 THAN RADIATION SURFACE PER METER = 1.5*26*12.2 = 485 M2 SO , ACCORDINGLY = 485/6 M2 PER METER PER TUBE = 79 M2 I TAKE TUBE SHELL TEMP. AT EVERY METER ALONG THE LENGTH OF TUBE FROM INLET TO OUTLET AT 6 LOCATIONS. I CALCULATE IT LIKE THIS 1 500K 79 M2 = KCAL/HR/M2 *79 2 600K 79 M2 = KCAL/HR/M2 *79 3 550K 79 M2 =KCAL/HR/M2 *79 4 573K 79 M2 =KCAL/HR/M2 *79 5 589K 79 M2 =KCAL/HR/M2 *79 6 600K 79 M2 = KCAL/HR/M2 *79 SUM IT IT WILL BE KCAL /HR IS IT CORRECT? RAJ