When a baseball or a rock smashes a hole through a school window, it's clear to even a first-grader that there is a problem. Nothing remains to keep the outside elements-wind, rain, noise and more-from entering a classroom and disrupting the environment or damaging the interior.
But aging windows can cause similar, though less detectable, problems for schools. Windows may appear intact, but the frames may have become rotted and corroded. That was happening with some of the windows in the Leicester Memorial School, which houses grades 3 through 5 in Leicester, Mass.
Windows put in place when the school was built in 1954 did not provide the energy efficiency and insulation that new windows can. And after being battered by vandalism, stormy weather and student use for more than 40 years, the wind whistled through many of the school's 9-by-12-foot window frames.
"We might as well have not had any windows at all, they were leaking so bad," says Carl Wicklund, facilities administrator for the Leicester School District.
The district followed the path that many education institutions have in upgrading windows: installing units that improved energy efficiency, while using available natural light to complement classroom lighting fixtures.
Money out the window Worn-out windows and frames not only allow unwanted heat and cold into a classroom and boost a school's energy bill, but also they can let rain and other moisture seep into a building and damage walls, floors and ceilings.
The Energy Efficiency and Renewable Energy Network, part of the U.S. Department of Energy, lists several ways to reduce the amounts of energy lost through inefficient windows.
"Low-e" glazings are special coatings on windows that lessen the amount of heat transfer. They are typically applied during manufacturing, but schools also can purchase low-e film to apply onto older windows.
Other glazings can absorb or reflect sunlight and heat before it reaches the classroom. Caulking and weatherstripping can reduce air leaks, and double- or triple-pane windows can provide greater insulation to repel the elements.
In Leicester, for the top two-thirds of the 9-by-12-foot classroom openings, the school installed translucent fiberglass. More traditional windows that can be opened were installed in the bottom third of the openings.
The fiberglass lets about 25 percent of the natural light to filter into the classroom-enough, Wicklund says, to brighten the room without overheating it or causing a glare that would distract students.
"Instead of being dark and gloomy, the rooms are bright and cheerful," says Wicklund.
Make it natural Many schools built a generation ago had a minimal number of windows. Districts felt fewer windows made air-conditioning more efficient, reduced external noise and vandalism, and saved on maintenance costs.
But the pendulum has swung, and many school designers now are advocating greater use of natural light in classrooms. Their rationale, backed up by some studies, is that exposure to natural light can help improve student performance.
The translucent windows at Leicester also meant that teachers didn't have to wrestle with the ungainly 9-by-12-foot venetian blinds that they once needed to control how much sunlight entered the rooms. And, while the new windows allowed natural light into the rooms, the brightness did not overwhelm the classrooms.