To sustain world growth, energy use must increase. However, if increased energy use is not accompanied by energy conservation, the increased energy use may create environmental problems. Carbon neutrality is an important goal to consider when evaluating energy use; organizations trying to achieve carbon neutrality are exploring ways to optimize energy use, minimize waste energy, and minimize carbon use. Energy conservation must be addressed in current (retrofit) and future designs. One method of conserving energy and maximizing energy use is with enhanced heat transfer surfaces. Enhancing heat transfer and increasing the efficiency of heat exchangers are essential in trying to maximize heat transfer performance.