This study addresses the comparison of CFI over shell and tube heat exchanger. Helical coils have been used in place of baffles as well as of tubes by which, cost is decreased for the same heat exchanger. Normal CFI gives higher heat transfer rates, heat transfer coefficient and less pressure drop up to certain range of Reynolds no. Although everything goes in favor of CFI but simultaneously it has a drawback that at higher Reynolds no. its thermal characteristics get down.