Virtis, a company that makes equipment for freeze-drying technology, is planning to use a new HFC refrigerant designed to work with mineral oils. The refrigerant has an ASHRAE designation of R-417A and consists of 50% 134a, 46.6% 125, and 3.4% 600 (butane). It is being produced and packaged by ICOR International of Indianapolis, IN, under the name NU-22.
The company said the refrigerant is rated A1 in terms of toxicity and flammability safety. The use of 125 and 134a allow for the refrigerant to be used “with wide temperature ranges,” said ICOR’s Gordon McKinney. The butane provides “for adequate oil return” when used with mineral, alkylbenzene, or POE oils, he said.