Let The Light Shine Through Without the Heat

double hung windows atlantaOne of the most obvious ways high-performance energy-efficient windows Atlanta Homes and buildings is by minimizing solar heat gain, but visible transmittance (VT) clearly offers additional benefits. Simply put, VT measures how much natural light can enter your home or building. It’s measured on a scale from zero to one. A higher number means more light can enter.Strange though it may seem, there exist many wavelengths in the electromagnetic spectrum that the human eye cannot detect. Unlike common goldfish, which are widely-believed to see infrared and ultraviolet light, both are invisible to humans.

Visible Transmittance: Let the Light Shine through Without the Heat

While this doesn’t directly affect energy use, it has an indirect impact by reducing reliance on electric lighting.

Choosing just the right level of VT can also make the indoor environment more pleasant and comfortable, emitting enough light to brighten rooms without causing glare on the television screen, for example. The right level of VT can also add privacy and reduce the fading of furniture and artwork, which is caused primarily by excessive exposure to ultraviolet light.

Solar Heat Gain & VT Make Homes More Comfortable & Energy-Efficient

VT is influenced by the glazing type, the number of panes, and any coatings, films, or tints. Levels of VT range from over 90 percent for uncoated water-white (picture frame) clear glass to less than 10 percent for coated or tinted glass.The VT of a typical double-pane Insulated Glass Unit (IGU) is 75-80 percent. Adding attachments such as blinds or shades allow modulating the transmittance to meet changing needs and to suit individual tastes and preferences. In the past, coatings designed to reduce solar heat gain also reduced VT. The nanomaterials revolution, however, has produced innovations such as adding thin layers of metal and metal oxide to windows, enabling them to block high levels of heat-generating infrared light while allowing the majority of visible light to pass through.

Solar heat gain and VT work in unison to make homes and buildings more comfortable and energy efficient, so be sure to check both before making a purchase. Combining low solar heat gain with high visible transmittance will help your energy dollars go further. Energy-efficient windows can provide peace-of-mind, while saving homeowners money on energy. We help homeowners solve problems and increase their homes value.

Tom Herron is the National Fenestration Rating Council’s senior manager, communications and marketing and a LEED Green Associate. You can reach him at 240-821-9505 or therron@nfrc

Call Jeff today for more information on energy-efficient windows Atlanta.  770-318-8514