What is the difference between the HEAT DRY and AIR DRY options?

With HEAT DRY selected, air inside the dishwasher is heated during the dry part of the cycle. With AIR DRY selected, the air is not heated, which helps save energy but means dishes take longer to dry (overnight) and some water spotting may result. Some items such as plastics may need towel drying when using the AIR DRY option.