Windows Open the Way for Energy Savings

Warm and cold-climate window tips for your home.

U.S Department of Energy

Windows can be one of your home's most attractive features, but they account for a significant portion of your utility bill. The U.S. Department of Energy has some cold and warm-climate tips to help you save money.

Windows provide views, day lighting, ventilation, and solar heating in the winter, but they also account for 10 to 20% of your heating bill.

During the summer, your air conditioner must work harder to cool hot air from sunny windows. Install ENERGY STAR windows and use curtains and shade to give your air conditioner and energy bill a break.

If you live in the Sun Belt, look into new solar controlled spectrally selective windows, which can cut the cooling load by 10 to 15%.

If your home has single pane windows -- found in almost half of U.S. homes -- consider replacing them. New double pane windows with high performance glass (for example, low-e or spectrally selective) are available on the market.

In colder climates, select windows that are gas filled with low emissivity (low-e) coatings on the glass to reduce heat loss.

In warmer climates, look for windows with spectrally selective coatings to reduce heat gain.

If you are building a new home, you can offset some of the cost of installing more efficient windows because doing so allows you to buy smaller, less expensive heating and cooling equipment.

Cold-climate Window Tips

• Use heavy-duty, clear plastic sheeting on a frame, or tape clear plastic film on the inside of your window frame during cold winter months. Remember, the plastic must be sealed tightly to the frame to help reduce infiltration.
• Install tight-fitting, insulating window shades on windows that feel drafty after weatherizing.
• Close your curtains and shades at night; open them during the day.
• Keep windows on the south side of your house clean to let in winter sun.
• Think about installing storm windows, which can reduce heat loss through windows by 25 to 50%.

Warm-climate Window Tips

• Install white window shades, drapes, or blinds to reflect heat away from the house.
• Close curtains on the south and west-facing windows during the day.
• Install awnings on the south and west-facing windows.
• Apply sun-control or other reflective films on south-facing windows to reduce solar glare.

For Your Long-term Savings

Installing new, high performance windows will improve your home's energy performance. While it may take many years for new windows to pay off in energy savings, the benefits of added comfort and improved functionality may make the investment worth it to you.

When shopping for new windows, look for the National Fenestration Rating Council (NFRC) Label (it means the window's performance is certified).

Remember, the lower the U-value, the better the insulation. In colder climates, a U-value of 0.35 or below is recommended.

Select windows with air leakage ratings of 0.3 cubic feet per minute or less.

Keep in mind that new windows must be installed correctly to avoid air leaks around the frame. Look for a reputable, qualified installer.

This article, and hundreds more, can be found on the NEA Member Benefits Web Site in the “Member Library” section: http://www.neamb.com/consumer_articles.jsp.