| 摘要 |
PROBLEM TO BE SOLVED: To lessen a heat loss and to melt snow efficiently by a method wherein a branch duct is provided in extension from a frame pipe for the structure supporting a film structure roof of a dome type and warm air is released toward a film surface from holes formed in the duct, while heat is radiated from the branch duct itself. SOLUTION: A main duct 6 connected to a warm air generator is laid in the shape of a double ring through the hollow inside of an upper frame pipe 2a. A plurality of branch ducts 7 joined to the outer peripheral parts on the opposite sides of the main duct are made to pierce the upper frame pipe 2a and opposed to a film roof 3 and warm air is let out from outlets opened in the outer peripheries and the fore ends of the ducts. These branch ducts 7 themselves radiate the heat obtained by heating and it is used for heating the film roof 3. Even when the frame pipe for the structure is disposed at large intervals, accordingly, the warm air can be blown against a roof surface evenly and, besides, the branch ducts themselves can be utilized for melting snow. |
