Drying device, printing apparatus, and control method thereof

A printing apparatus comprising:

• a conveying unit configured to convey a medium to which a liquid is discharged from a discharging head;
• a hot air blowing unit including a blowing unit configured to blow air, and a heating unit configured to heat air;
• a passage forming unit configured to form, between the hot air blowing unit and a region on a conveyance path of the conveying unit, a circulation path through which air blown from the hot air blowing unit is to be circulated;
• an adjusting unit configured to adjust a ratio between inside air circulating through the circulation path and outside air, outside the circulation path, that is introduced into the circulation path;
• and
• a control unit configured to control the adjusting unit,
• wherein, if a temperature increase instruction from a user is received through an input device, the control unit controls the adjusting unit to increase a ratio of the inside air, and
• if a temperature decrease instruction from a user is received through the input device, the control unit controls the adjusting unit to increase a ratio of the outside air.