The main focus of the work is to determine the performance efficiency of water-%CuO nanofluids and water at varied flow rate of 0.035 lit/sec, 0.045 lit/sec, and 0.065 lit/sec in an evacuated tube collector integrated with an heat exchanger. A heat exchanger made of copper tube connected to a horizontal pipe for collection of heat from a vertical tube, and a vertical copper tube for collection of heat from an evacuated tube collector for solar radiation were used in the investigation. Water showed no absorption, a low thermal capacity when it was not suitable for high thermal application for improvement in performance, the base fluid with colloidal dispersion of %vol CuO nanofluids in the force convection mode. The evacuated tube collector produced the highest efficiency of water -0.3% vol CuO nanofluids at flow rate 0.035 lit/sec compared to 0.1% and 0.2% vol of CuO nanofluids at flow rate of 0.045, 0.065 lit/sec and water. A comparison to the water CuO nanofluids with the highest effective concentration showed a greater increase in thermal efficiency.The performance of theworking fluid performances was examined for parameters like exit temperature, specific heat, thermal conductivity, energy productivity, and efficiency utilizing.