Air conditioning apparatus in plant cultivation

An air conditioning apparatus, comprising:

• a carbon dioxide generating unit that generates carbon dioxide;
• an air supply unit that supplies ambient gas or outer air;
• a mixing unit coupled to the carbon dioxide generating unit through a first duct, coupled to the air supply unit through a second duct, and configured to mix the carbon dioxide generated from the carbon dioxide generating unit and the ambient gas or the outer air supplied from the air supply unit, to form a mixed ambient gas;
• a plant cultivation apparatus;
• a hole defined in the plant cultivation apparatus;
• and
• connection pipes coupled to the mixing unit, and having outlets that supply the mixed ambient gas above the hole defined in the plant cultivation apparatus,
• wherein the connection pipes include a circular pipe portion arranged in a circle that is concentric with the hole defined in the plant cultivation apparatus,
• wherein the outlets are arranged on the circular pipe portion,
• wherein the circular pipe portion has a diameter D,
• wherein 100 mm≦D≦250 mm,
• wherein the outlets include at least three outlets and at least three of the outlets are arranged for the hole defined in the plant cultivation apparatus, and the outlets are installed so that angles formed by centers of the adjacent outlets and a center of the hole defined in the plant cultivation apparatus are equiangular or less than substantially 180 degrees, and
• wherein:
• a horizontal angle θ1 which is an angle when at least one of the outlets is directed toward the center of the hole defined in the plant cultivation apparatus is 0 degrees with respect to a line connecting the center of the hole defined in the plant cultivation apparatus and the center of the at least one of the outlets, and a clockwise direction at a time of rotation around the at least one of the outlets within a surface parallel to the plant cultivation apparatus is defined as positive, and
• a vertical angle θ2 which is an angle when the at least one of the outlets is directed toward the hole defined in the plant cultivation apparatus in a direction parallel to the plant cultivation apparatus is 0 degrees with respect to a top surface of the at least one of the outlets, and a vertical upward angle is defined as positive, and
• each of the outlets is installed such that (i) when the horizontal angle θ1 is 0 degrees or more and 25 degrees or less, the vertical angle θ2 is 30 degrees or more and 75 degrees or less, (ii) when the horizontal angle θ1 is above 25 degrees and 35 degrees or less, the vertical angle θ2 is 45 degrees or more and 75 degrees or less, and (iii) when the horizontal angle θ1 is above 35 degrees and 45 degrees or less, the vertical angle θ2 is 45 degrees or more and 60 degrees or less.