Neb. Rev. Stat. §§ 18-2306
The air conditioning air distribution board, subject to the approval of the city council or village board of trustees, may adopt rules and regulations, not inconsistent with the laws of the state or the ordinances of the city or village, for the designing, installing, altering, inspecting, or repairing of an air conditioning air distribution and ventilating system placed in or in connection with any building in such city or village or within the area of extraterritorial zoning jurisdiction of cities of the metropolitan class describing the kind and size of materials to be used in such systems and the manner in which such work shall be done. All plans and specifications for any such system to be placed in a building shall be first submitted to the board or other body designated by the city council or village board of trustees for its approval before such system shall be installed.
Neb. Rev. Stat. §§ 18-2306