Energy Efficient Windows 101

Windows not only affect the overall look of your home. They also protect your family from the elements when it gets too cold in the winter and too hot in the summer. With the right materials and proper insulation, your windows can help reduce your energy consumption too! Energy efficient windows are growing in popularity.

If you are building a house from the ground up, then you have more freedom in customizing the construction of your windows. However, most people do not have this option. They have to live with the original design of the home developer and wait for wear and tear before spending for a windows retrofit.

How to Make your Windows Energy Efficient

• Add stick-on plastic, low-E films to single pane windows.
• Install curved-end valances to enclose the whole frame.
• Extend the drapes all the way to the floor to conserve more heat.
• Add caulking, sealing or weather stripping to drafty windows.
• Replace warped and damaged aluminum windows

Window Technology Jargon

There are three important terms you need to know about window technology.

Glazing

This refers to a smooth, transparent sheet of glass or plastic. In a triple-glazed window, there are either three full glass panes or two glass panes with a plastic sheet in between. Many window builders inject gas – argon or krypton – into glazing spaces to reduce heat and noise.

Low-E

This refers to a very thin coating made of tin or silver oxide that is applied to the surface of an outer pane. During winter, it reflects infrared radiation to keep heat inside the home. During summer, low-E coating blocks harmful UV rays from the sun while still allowing visible light.

U-factor

This refers to how quick radiant heat gets through the center of window. They are the inverse of R-values, which measure how well insulation can stop heat gains and losses in walls. An energy efficient window will have a U-factor of around 0.35 to as low as 0.18.

Keep in mind that an energy efficient window will have more glazes, inert gas, and low-E coatings.

Low-E Glass Coating

Home windows are made of 75% glass. Heat loss from glass windows can significantly contribute to the annual heating costs of a home. This is why it is extremely important to install windows that can effectively maintain a comfortable interior temperature while blocking extreme hot and cold weather outside.

Low emissivity glass or Low-E is the best way to maintain comfortable temperatures inside the home and reduce energy costs. Consult with a professional window builder to make sure you have the appropriate Low-E coatings for your region.

Weather Sealing and Stripping

Weather stripping helps create a tight seal along window frames to reduce air infiltration and conserve energy.

These are the most common types of weather stripping:

• Reinforced foam
• Felt
• Vinyl tension seals
• Closed cell foam tape
• Gaskets
• Sweeps
• Bulb seals
• Magnetic weather stripping
• Window frame construction

Frame construction can play a crucial role in the energy efficiency of a window. Vinyl frames with foam insulation are the most cost effective, easy to maintain, and energy efficient. Other materials that are commonly for window frames are wood and cased fiberglass.

Gas-Filled Pane Gaps

Modern windows typically come with multiple panels of glass, Low-E coatings, and a gas-injected spacer system between the panes. The gas between gaps acts as an additional buffer between extreme weather outside and the atmosphere inside the home. They minimize heat loss and transfer between the panes of glass.

Argon is the most commonly used gas filling for window panes because it is non-toxic, non-reactive, clear, and affordable. Some builders use krypton to fill very small gaps but it is more expensive. Both gases conduct up to 50% less heat than air and provide added protection against condensation and cold weather when injected into a triple pane window.

Unless you are a building contractor, do not attempt to install your own windows. Trust only a professional to handle this job safely and efficiently. Contact ASP Windows and Doors today for a free consultation on energy efficient windows.