Refrigerant Oil Additives

Refrigerant oil additives are liquids designed to be introduced into all sorts of refrigeration systems, including air conditioners and chillers. According to vendors, these additives mix with refrigerant oil and improve heat transfer within refrigeration system heat exchangers. Vendors assert that the use of their products yields energy savings ranging from 5 to 30 percent of overall system energy consumption.

It’s not clear that these additives can consistently produce savings in the ranges that vendors claim—in fact, lab and field tests by independent, qualified laboratories indicate that the savings claims may be exaggerated. In addition, there’s a body of research that disassociates large gains in heat-exchanger efficiency from large gains in overall system efficiency.

But new research on the use of nanoparticles—extremely tiny particles—shows promise. Nanoparticles could be very effective as refrigerant oil additives because they’re more thermally conductive than existing additives, and they’re also much cheaper. The particles are composed of metal oxides or carbon and are being used today in products such as paints and certain food items for coloring. This technology has yet to be commercialized, but it holds promise as a cost-effective retrofit to existing air conditioners.

Uncertainties raised by tests
Uncertainties about savings mechanisms
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