What is AG3?
AG3 is a glass package developed exclusively by Win-Dor. It begins with a coating is a microscopically thin layer of metallic coating applied to a surface of an insulating glass unit and reflects heat. The AG3 coating reflects solar heat and UV rays back out into the atmosphere and away from the inside of your house. This keeps your house cooler reducing the amount of energy needed to run your air conditioning system during hot, summer months. It will also reflect heat from your heating system back into your home during cold, winter months. AG3 incorporates the glass, warm edge spacer technology along with reactive butyl sealant. Win-Dor uses AG3 as a standard in all of its vinyl windows and doors.
What is SHGC?
SHGC stands for solar heat gain coefficient. It is a measurement of the fraction of solar radiation admitted through a window, patio door. The lower the SHGC, the less solar heat it transmits. Win-Dor’s vinyl replacement windows and doors provide for low SHGC creating greater energy efficiency. For more information regarding solar heat gain coefficient, please visit the National Fenestration Rating Council at
What is U-Value?
U-value represents a product’s resistance to heat transfer and is a measurement of the total insulating ability of a window or patio door. It is used to measure all of the components that are part of the window or patio door: the frame, the spacer that divides the two panes of glass, and the glass itself. LowE2 and the insulating air space between the two panes of glass are also part of a U-value calculation. The smaller the U-value, the slower the transfer of heat through a window. Most energy efficiency programs, like ENERGY STAR, use U-value to recommend a window or patio door. For more information regarding U-Value, please visit the National Fenestration Rating Council at
What is visible transmittance?
Visible transmittance is a measurement of how much light is transmitted through a product. It is expressed a numerical value between 0 and 1 The higher the visible transmittance, the more light is transmitted. For more information regarding visible transmittance, please visit the National Fenestration Rating Council at