RetroWAL™ Platinum Series
The RetroWAL™ Platinum Series features two panes of tempered glass, carefully separated by a small air-less gap. Maintained by a matrix of micro-spacers that hold the glass panes in place, the space is void of air molecules and virtually eliminates thermal conduction and convection, two of the three most common sources of heat loss in a window. The other – thermal radiation – is minimized by a low-e coating on the glass to minimize the amount of ultraviolet and infrared light that can pass through the window. By combining advanced insulating technology and low-e glass, the RetroWAL™ Platinum Series improves the center of glass R value up to 12.5, far outperforming traditional replacement insulating glass units.
The two examples above use Windows 6.3 modeling software. In each case, the RetwoWAL™ system utilizes a 2” airspace from the existing window. The IGU is uncoated and has a ½ airspace. These values are for COG or Center of Glass.
One other factor not taken into consideration in this table is the reduction in air leakage around the gaskets of the glass. RetroWAL™ has been tested to dramatically reduce air leakage.
R Value: This is the measure of thermal resistance and is in the English units BTU/(h °F ft2).
U Value: This is the reciprocal of R value and is used in the fenestration and window industry.
SHGC: This is the Solar Heat Gain Coefficient and is the energy transmittance of the glass window due to solar radiation. It ranges from 0 or totally blocked to 1 or direct sunlight.
VL: Is the Visible Light transmitted through the glass. The idea is to maximize the amount of natural light but to minimize the solar heat of infrared radiation. The values range from 0 to 1.
Weight: This is the additional weight per square foot the RetroWAL™ system adds to the window opening. In large curtain wall buildings it is important to maintain the structural integrity of the window and add as little weight as possible.