Protecting the Skylights
At a zoo, keepers prepare food in a care room beside the okapi habitat. Windows in the roof, called skylights, let daylight into the room. During a storm, falling hail cracked a skylight. Rain then dripped onto the work counter. The zoo wants a guard above each skylight that can reduce damage while letting daylight through.
A class built small models to compare guards. Tissue-paper squares stood for skylights. Tears in the tissue stood for damage. The class tested wide mesh, fine mesh, a clear panel, and solid card. Mesh is a material with many openings. They also tested an open frame with no guard.
For each design, the class tested ten new tissue windows. An adult dropped one soft clay ball above each window from the same marked height. The class used balls of the same size and kept the window size and guard height the same. They counted torn windows, then repeated the test twice with fresh tissue. Each design had thirty window tests altogether.
The class also measured light beneath each guard using the same lamp and meter. A higher meter score meant more light. These were indoor model tests, away from animals.