When the effective operation of a building or structure, or equipment within a building or structure, necessitates placing machinery, motors, generators or similar devices for cooling, heating or generating purposes, outside or on top of any structure, they shall be screened from public view. Said screening may consist of the following:
1. Densely planted evergreen shrubs, which shall grow to not less than five feet after one growing season, and
2. A solid and uniform fence at least five feet in height on four sides of said equipment, or
3. A masonry wall at least five feet in height on four sides of said equipment, or
4. Extensions of parapet walls or mansard roof lines or structural or ornamental screens or baffles, or
5. Any similar type of solid or uniform screening, which will prevent exposure of such equipment to public view.