Energy Efficient windows
What are Green or Energy Efficient windows?
Green or energy efficient, windows are windows that transmit the least amount of heat and reduce your home energy output. They also protect your home temperature from being affected by the external weather.
- Most of the heat loss in the home is caused by the windows, because of the type of glass and/or type of frame. This is because older windows, typically aluminum windows, are conductors meaning they transmit heat and cold.
- Installing green windows into your home will not only maintain the desired temperature of your home but in the long run will save you money on heating and cooling bills. Windows that are considered "green" insulate your home and decrease heat transfer making your home more energy efficient.
What determines energy efficiency of a window?
The type of glass used for a window, determines its efficiency rate how much and what kind of light will be let in.
- The newest technology for glass allows for a large reduction in heat loss. With a particular type of glass called "Low-E," or low emissivity, energy efficiency becomes possible.
- Low-E glass allows the visible light to enter the home, but blocks the bad light that damages skin and cause colors to fade. For the highest efficiency, the space between the panes is filled with argon gas to further insulate.
- Warm edge spacers in between the panes also reduce heat transfer as well as insulate the edges creating a highly efficient "green" window.
- For even greater efficiency, the frames of energy efficient windows are made with materials that also help reduce heat transfer while increasing insulation, like vinyl or fiberglass.
The circle graph above shows that one-quarter of your carbon footprint consists of home energy use, but this can vary depending on the kinds of energy sources available to power your home. ENERGY STAR calculates carbon savings for ENERGY STAR windows, doors, and skylights based on the mix of fuels in a region and the estimated energy use for a typical home.