Microchannel heat exchangers have been widely considered as a revolutionary, advanced technology because they can provide more than 50% reduction in size and mass, refrigerant charge and air side pressure drop. Wide use of microchannel heat exchangers will make a significant contribution to reduction of energy consumption and consequently carbon emission. The research involves theoretical modelling and accurate measurements. It aims at providing fundamental understanding of the phenomena and accurate, reliable and robust prediction methods for heat transfer and pressure drop for design and optimisation of microchannel heat exchangers.