in ; tube id 0.834 in ; tube pitch = 2 in (square pitch) ; k = 26 btu/ft-hr-F There are 10 tube rows with each row containing 60 tubes 30 ft long The inside heat transfer coefficient, hi, = 1200 btu/hr-ft2-F The tubes are "finned" resulting in a total outside surface area of 3.8 ft2/ft ; The fin efficiency is 0.95 The area of the bare tube exposed (not covered by the fins) is 0.2 ft2/ft Air-side: Air is flowing outside and perpendicular to the tubes at 15.05 ft/s Air enters the exchanger at 80F and leaves at 180F Air properties at the Air bulk temperature are as follows: Air is at atmospheric pressure viscosity = 0.046 lb/ft-h Cp = 0.25 btu/lb-F k = 0.0162 btu/ft-h-F Fa (air flow arrangement factor) can be assummed to be 0.95