Chiller systems are used to cool water or other fluids for industrial and commercial applications. There are two main types of chiller systems: air-cooled chillers and water-cooled chillers. Air-cooled chillers use air to cool the refrigerant, while water-cooled chillers use water to cool the refrigerant. Air-cooled chillers are typically used in smaller applications, as they are more cost-effective and require less maintenance. Water-cooled chillers are typically used in larger applications, as they are more efficient and require less energy to operate.