The simple answer is dry air protects your products, your tools, and your equipment.  Air compressors will always produce water as a by-product of making air.  Refrigerated air dryers cool the air down and keep it dry, much like your air conditioner in your home.  Buying a good used refrigerated air dryer is a great way to save money and save your products, tools, and equipment from water damage.  We always have a good selection of used refrigerated air dryers and desiccant air dryers to choose from.  We stock used air dryers from 50 CFM up to 1000 CFM.  Air dryers if well maintained can last many years, investing in a used air dryer could save you literally thousands of $$$!