Asiana Airlines Premium Economy booking class is known as Economy Smartium. Some of the conditions that apply to Economy Smartium seats are as follows: ● Flight changes and refunds are possible only up to 48 hours before departure.  ● Refunds are possible only if the reserved seat is not available for some reason and will be made at the point of purchase.  ● If you’re travelling on an Ecomomy Smartium ticket on a long-haul flight to the USA, Europe, or Oceania from Incheon International Airport, you will have access to the airport’s Business Class lounge.