Wednesday was energy day at the Glass Association of North America’s (GANA) Annual Conference, underway this week at the Coronado Island Marriott Resort and Spa. Numerous speakers throughout the day focused on the topic and how glass relates. During the energy division session, the group heard from Mudit Saxena of Heshong Mahone Group who gave a presentation titled “Daylight, View and Windows: the Human Connection.”
Saxena asked the question: What is a window’s purpose? If windows could answer, he said, they would likely say they want humans to have a view and daylight.
“That’s the purpose of putting a hole in the wall in the first place,” said Saxena. “You [the glass industry] are in the view and daylight business.” He explained that view is an essential value provided by windows; heat flow management, weather protection, etc., are secondary.
“They are not why a window exists,” he said, noting that numerous studies have shown the benefits of daylighting, such as improved learning abilities in school and increased productivity in the workplace. But view remains the big winner in all of these studies.
“Window design is a balancing game between light, heat and view,” said Saxena.
However, there can be challenges in design, such as glare, that can cause architects to either use fewer windows or design with very dark glazing.
Saxena said yes, glare is a problem, “but it is not the window’s problem. You can solve glare with cheap and simple solutions: blinds and shades,” he said. “If you make it a window problem you will end up with the black window glass of the 1980s.”
He said the energy solution is a simple calculation; the question, though, is what are we solving: is it finding the lowest energy use; is using less glass better? Saxena answered that when designing a healthy building with daylight views “the answer is not to decrease the use of glass, but to use window products that provide daylight and views with the [smallest] energy penalty.”
According to Saxena, the design approach should be to first optimize the window orientation for daylight and views and then solve the energy equation to achieve the least amount of energy use.
He said there is still research and data needed.
“We need to optimize window performance,” he said. “One good dataset enables all kinds of research.”
GANA’s annual conference continues this week. Look to usgnn.com™ for more news and reports from the event.