The optimal humidity range for a refrigeration system depends on the specific application, product, or process being cooled. For example, in food storage, a relative humidity (RH) range of 80-90% is often recommended to prevent drying and spoilage. In pharmaceutical storage, a narrower RH range of 40-60% may be required to maintain product stability. In industrial processes, the optimal humidity range may vary depending on the process requirements. It is essential to consult industry guidelines, product specifications, and process requirements to determine the optimal humidity range for your refrigeration system.