Over last few decades, usage of energy has increased due to increase in population and industrialization there for researchers have been engaged in energy saving strategies as well as source of energy. So in order to minimize energy consumption, compact and efficient thermal system are being design and develop so helical coil heat exchangers are most usable thermal system. Helical coiled tubes are effective as heat transfer equipment due to their compactness and increased heat transfer coefficient parameters in heat exchanger. Heat transfer in curved and helical circular tubes has been the subject of several studies due to the relatively high heat transfer coefficients associated with them. Flow in curved tubes is different from flow in straight tubes because of the presence of centrifugal forces. The centrifugal forces generate a secondary flow, normal to the primary direction of flow, with circulatory effects, that increases the rate of heat transfer.