Window Energy Savings
Low-E Glass-making the difference.
Low emissivity glass, or Low-E glass, is an excellent way to increase your home's comfort and energy round. All Liberty Window products with the ClimaTech Glass Package utilize SolarBan® 60 Low-E glass from PPG. PPG's SolarBan 60 is created by applying multiple layers of microscopic, undetectable metallic coatings to the surface of a piece of flat, annealed glass. This coating helps to block out solar energy in the summer while retaining furnace heat and allowing warm short wave solar rays in the winter.
Low-E glass filters long-wave radiation from the sun. This reduces solar heat gain from the summer sun, helping to keep your home cooler. Additionally, in the summertime where windows are exposed to direct radiation, ClimaTech's Low-E coated glass blocks unwanted ultraviolet radiation and reflects away the long-wave infrared radiation that can add heat to the inside of your home.
Low-E glass takes on a new responsibility in winter months. It lets warm solar rays into your home, while blocking the heat inside your home from getting out. In cold weather, you spend your energy dollars generating long-wave radiation, as in heat from a furnace. That heat moves toward your cooler windows, but ClimaTech acts like a mirror, reflecting it back inside to help you save money!
Understanding U-Factors, a valuable lesson.
For all window products, the NFRC has created NFRC-100, which is the standard test for heat loss through a fenestration, or window product. Once the testing procedure has been completed, aU-Factor rating is applied to the window product. The lower the U-Factor, the better the product is at resisting heat loss. This chart easily illustrates why a window containing Low-E glass will thermally outperform windows with any of the lesser glass products.
U-Factors are often measured in two ways, the center of glass (COG), and the whole window. The NFRC requires that the whole window U-Factor, meaning the performance values of the entire unit be displayed. Glass manufacturer's however, when depicting the energy efficiency of their products, often rely only on the center of the glass unit for their testing purposes.
Consumers must be careful when comparing U-Factor performance ratings from one product to another.
The glass unit by itself will yield a superior performance rating, and may often be used to indicate the total windows performance values. This is not an accurate comparison. When choosing the best products for your home, it is critical to be presented with an "apples to apples'; or whole window performance comparison to help with your decision.
PPG Solarban 60 Low-E Glass.
Offering you the ultimate in energy efficiency.
Out of the many different styles of homes we see every day, it might be hard to realize, but each one of those homes will have heating and cooling requirements to enable that homeowner achieve the utmost in year round comfort within their home. Just as the ENERGY STAR label depicts different heating and cooling needs for northern and southern climates, so too must a window prove to be versatile enough to be efficient in many different climate or seasonal situations.
That is why the ClimaTech Insulated Glass Package relies on the many energy performance characteristics of PPG's Solarban 60 Low-E Glass. Shown below are three of the most critical performance requirements that should be considered when choosing an optionally enhanced glass unit for your new windows. It is important to note however, that since the benefits of Low-E glass and argon gas only are depicted below, the center of glass (COG) measurement has been displayed.
Improving a Window's Winter U-Factor Performance.
The U- Factor (also referred to as U-Value) is a number that represents the rate of heat flow through a glazing system. The lower the U-Factor, the greater a windows resistance to heat flow, and the better its insulating value. This performance is critical to those homeowners who may experience increased heating conditions not only during the winter months, but very possibly late fall and early spring as well. The Solarban 60 unit will outperform the standard clear unit by as much as 51 %.
A Solution for Solving the Solar Heat Gain Coefficient Dilemma.
The solar heat gain coefficient (SHGC) is a number that represents the fraction of solar radiation admitted through a window, both transmitted and absorbed, and subsequently released inward. The lower a window's solar heat gain coefficient, the less solar heat it transmits, which therefore leads to greater shading ability. Climates that rely heavily on air conditioning will benefit from a window product that displays a lower SHGC. As shown, the Solarban 60 unit will outperform the standard clear unit by as much as 49%.
Reducing UV Energy While Maintaining the Visible Light.
Ultraviolet light (UV) are the invisible rays of the spectrum, and are found in everyday sunlight. These rays of light are responsible for the fading of carpets, fabrics and even paint finishes. Visible light is simply that, the portion of the electromagnetic spectrum that produces light that can be seen. Solarban 60 Low-E Glass reduces harmful UV rays by as much as 72%, while still allowing about 88% as much visible light as a standard clear unit.
