In the wake of energy crisis, the transportation of energy with the application of heat exchangers has become a vital issue. Present research has focused on the enhancement of heat transfer performance of heat exchangers by the application of highly efficient heat exchanging liquids. The scientists have done a remarkable amount of work and researchers on alteration of heat transfer surfaces, process parameters and flow passage configurations etc. There are limited works reported about heat exchanging liquids and their modifications. Present research was focused on synthesis and application of more efficient nanoparticle-based heat-exchanging liquids such as ZnO and bio-based functionalized graphene for heat exchangers. Different types of synthesized nanofluids were experimentally tested in single tube and annular flow passage heat exchangers and different regime and multiple range of Reynolds number. Heat transfer enhancement of about 30 percent, for metal oxides and composites of oxides were observed whereas about 40 percent enhanced was noticed in case of carbon structured and their composites based nanofluids with the low enhancement in pumping power. As the newly bio-based synthesized nanofluids have shown a noticeable enhancement of heat exchanger performance, so it can be considered as a high-performance heat exchanging liquid for future generation heat exchangers.