Nanolubricants are nanoparticles finely dispersed in a lubricant – are a potential cost-neutral technology that is able to increase the energy efficiency of HVAC&R systems. This talk focuses on the nanoparticles interaction with the working fluid during phase change processes. The speaker will provide a summary of the research conducted on smart nanolubricants with the support of the ASHRAE IRG. Nanolubricants provided augmented heat transfer rate in the heat exchangers with very small pressure drop penalization. The oil in circulation with the refrigerant in air conditioning system components was transformed from an unwanted contaminant to an effective energy efficiency promoter.