Active (X) vs. Stationary (O) Panels:
In the business of windows and doors it’s important to always keep in mind which part of the product is going to move and which will stay stationary. Most companies use the X and O system, respectively representing active and stationary. We always view the window product from the outside and read left to right. From the outside: XO = Left is Active and Right is Stationary. XOX = Left and Right are active, while center is stationary. XX = both panels are active. OX = Left is Stationary and Right is Active.
Spectrally Selective Low E Coatings:
A coating that allows short wave energy (such as energy emitted from the sun) to pass through the glass while long-wave infrared energy (such as heat from your furnace)is reflected back into your home. Essentially the Low E coatings have been tuned to let energy into your home that heats up your items in your house, and then drastically slows the speed in which the heat is lost.
Solar Heat Gain Coefficient:
The percentage of solar heat that is entering the structure through the window unit. The lower the SHGC number the better the window.
The U-Factor is the rate of non-solar heat gain or loss, displayed as a percent. This factor is displayed on all NFRC (National Fenestration Rating Council) certified windows. The higher the number the less efficient the window will be in your home. In general, products such as wood, vinyl, and fiberglass, in addition to the use of dual pane glazed windows with Spectrally Selective Low E type coatings would have a better U-Value than the single pane aluminum windows that are found in many older homes. Visit the Milgard or PPG website if you want to find out more, or give us a call and we can help with finding the appropriate products for your application.