Effects of Refrigerant Oils and Molecular Sieve on Air Conditioner using Alternative Refrigerant

대체냉매를 사용한 에어콘에서 합성오일과 건조제(M/S)의 영향

To protect the ozone layer, R22 will be replaced with HFCs. R407C is a leading candidate as alternative refrigerant for air conditioner due to its similar thermodynamic characteristics with R22. In replacing R22 with R407C, the compatibility with lubricating oil is of major concern. Polyol ester (POE) oil among the synthetic oils is considered to be the best lubricant for use with R407C because of good electrical properties and miscibility. However, lubricating ability of mixture of R407C/POE oil is lower than that of R22/mineral oil due to the production of acid by hydrolysis which causes corrosive wear. Therefore, to minimize water content, it is needed to develop a molecular sieve desiccant which is compatible with R407C and ester oil. This paper discusses (1) the change of properties of POE oil when current molecular seive is used, (2) the effects of POE oils and additives on durability of compressor. Through compressor life test and bench wear test, it was found that inadequate use of POE oils and additives may promote the deteriation of molecular sieve, resulting in decrease of durability of compressor.