POLAR WATER COOLED PACKAGED AIR CONDITIONERS / WATER-COOLED CEILING AIR-CONDITION - unit casing is constructed of electro-galvanized steel sheet,casing surface is finished with epoxy polyester power coating. - extra high efficiency is attained by tube-in-shell condenser and specially designed screw thread - surfaced tubes. - complete with safety protection and error indication system. - units designed for easy servicing. - each unit is factory leak-tested,evacuated,dehydrated,precharged with refrigerant and performance-tested before delivery.