Windows, the eyes of our buildings, let our imaginations soar with their views and brighten our interiors with natural light. But they also represent major holes in our buildings through which energy (and money) pours. Each year, American taxpayers spend over $25 billion on summer air conditioning and winter heating. Although a wealth of new glazing products promises to reduce this energy drain, the challenge of finding the right product for each building can boggle the most adept architect.
So how do you sort through the myriad of products and specifications to pick the right glazing for the job? The energy specifications that describe glazing performance are key indicators of which glazing is best for each application.
High Visible transmission values are important to deliver as much daylight as possible, but may produce glare unless the glazing is protected.
Let the Daylight In:
Solar energy is composed of Ultraviolet (UV), Visible and Infrared (IR) radiation. Glazing types differ in how much they transmit in each of these regions. Bringing in daylight through windows and skylights counts on the transmission of energy in the visible part of the spectrum.
Visible Light Transmission (VLT): This specification indicates the percentage of visible light that is transmitted through the window.