Nanorefrigerants: A comprehensive review on its past, present and future

• All the aspects of nanorefrigerants have been reviewed.
• Various nanorefrigerant preparation methods have been addressed.
• The boiling heat transfer may get enhanced or deteriorated by the addition of nanoparticles.
• The refrigeration systems become more energy efficient by the addition nanoparticles in the refrigerant or refrigerant-oil mixture.

Nanofluid as a heat transfer fluid has been gaining popularity ever since its inception. Consequently, the researchers and experimentalists from the refrigeration industry could not keep themselves away from the ever growing horizon of nanofluid applications. The research on the refrigerant based nanofluids or a nanorefrigerant is slowly but surely increasing. The boiling heat transfer coefficient data for nanofluids and nanorefrigerants have been inconsistent but, in general, researchers have observed a rise in the boiling heat transfer coefficient that encourages them to pursue their research further in this field. Numerous studies regarding nanorefrigerants have shown that the addition of nanoparticles lead to a better system performance and energy efficiency. This review paper is an attempt to summarise all the aspects of nanorefrigerants such as its preparation, thermophysical properties, pressure drop in nanorefrigerants, boiling heat transfer and performance of nanorefrigerants in various domestic refrigerators.