What Makes Windows Energy-Efficient?

When it comes to saving money on energy bills, many people think of insulation, programmable thermostats and CFL (compact fluorescent lamp) bulbs. But your windows also have a huge impact on your home’s energy.

Replacing your old windows with new energy-efficient models can help you reduce your heating and cooling costs. Keep reading to learn more about what makes windows energy-efficient!

Window Energy Efficiency

Factors that affect a window’s energy efficiency include:

Material: Certain materials have higher thermal efficiency than others. Vinyl windows (which we offer) are very energy-efficient

Style: The style of the window can influence its energy efficiency. Due to the tight seal created between the sash and the frame, casement and awning windows tend to be some of the most energy-efficient types of windows. Picture (fixed-pane) windows, which don’t open, are also energy-efficient.

Type of glass: Many windows today come with low-E glass—or have it as an option. This type of glass has coatings that help keep heat inside your home during the winter and outside in the summer.

Panes: Two panes of glass are better insulators and can also help with impact resistance and sound control. Many windows also have gas (usually either argon or krypton) between the panes, which increases their ability to stop heat transfer.

Spacers: A window’s spacer keeps the panes the correct distance apart. Non-metallic spacers help reduce heat transfer by insulating the edges of the panes.

ENERGY STAR & Window Testing

You have probably heard the term “ENERGY STAR” when it comes to window replacement, but what exactly does it mean? How does a product get an ENERGY STAR label? ENERGY STAR qualified replacement windows:

  • Are manufactured by an ENERGY STAR partner
  • Are independently tested and certified by the National Fenestration Rating Council (NFRC)
  • Have NFRC ratings that meet strict energy efficiency guidelines set by the U.S. Department of Energy (DOE)

Qualified products must be 40 percent more efficient than common building codes and reduce energy bills by at least 15 percent. ENERGY STAR qualification is based on NFRC certified product ratings.

The ratings provide information about the window’s:

  • U-factor (measures how well a window prevents heat from escaping a home)
  • Solar Heat Gain Coefficient (measures how much  heat from the sun is blocked)
  • Visible Transmittance (measures how much light comes through a window)
  • Air leakage (measures how much outside air comes into a home through a window)
  • Condensation resistance (measures how well a window resists the formation of condensation)

Learn more»

The ENERGY STAR label was initially created to accomplish two things:

  • Make it simple for consumers to buy energy-efficient products that offer great savings but are just as convenient and reliable as conventional products
  • Reduce greenhouse gas emissions and other harmful pollutants caused by inefficient energy use

Energy-Efficient Windows in Indianapolis

If you live in central Indiana and are in the market for new energy-efficient windows, Overhead Door Co. of Indianapolis & Muncie can help. We offer products from American Window and Great Lakes Window that are ENERGY STAR qualified. Contact us to learn more!