Synthetic Refrigeration Oils - Humidity Related Difficulties and Solutions

New lubricants have been developed to meet the performance demands of modem refrigerants and system components. A brief review of current refrigeration oil developments is presented. It is well known that the new lubricants used with polar refrigerants tend to absorb water. The ester hydrolysis process and the effect on the essential lubricant properties are described. The effect of increased water content on compressor performance is outlined and a test method to determine the hydrolytic stability of ester lubricants is presented. Polyglycol (P AG) lubricants are also discussed. Possible system problems associated with the hygroscopic nature of these lubricants are outlined. Rechargeable container systems for filling compressors under exclusion of air, special oil dehydration techniques and innovative new lubricant developments are presented.