Abstract: electricity consumption by refrigeration equipment is about 20% of the total energy consumption. Ways to improve the efficiency of refrigeration units is one of the most urgent tasks in the light of the general policy of energy saving in the world. The efficiency coefficient of refrigeration machines depends on the efficiency of heat exchange in the system. In addition to the obvious ways to improve the design of the refrigeration circuit itself, there are a number of alternative solutions to improve the energy efficiency of heat exchange processes. Among them there is the addition of metal oxide nanoparticles to the circuit, which have a high heat transfer coefficient. The article presents a review of the literature on the use of nanoparticles in cooling systems, which describes the energy efficiency from 9.6% to 28% depending on the material of nanoparticles and their concentration. Also, an experimental refrigeration unit was manufactured, where copper oxide nanoparticles in a concentration of 1% were used. This installation showed a decrease in electricity consumption by 18%, as well as a better dynamics of temperature decrease.

Keywords: nanofluids, refrigeration systems, freon, heat transfer, nanotechnology, energy saving, energy efficiency