On The House July 2011

Wading through all those energy-saving claims

By Arnie Katz
Wading through all those energy-saving claims

Q: I’d like to reduce my energy bills to save money and improve the environment, but I find a lot of conflicting information about the best ways to do it. What can I do in my home that will really make a difference?

—Brenda, Siler City

A:Brenda, you’ve put your finger on a real problem. You’d think that after several decades and gazillions of dollars of research, it should be relatively easy to answer that question. The problem is that there are so many factors influencing what happens in a particular house, coming up with clear, one-size-fits-all advice is very difficult.

One certainty is that reducing your use of energy regularly will reduce your energy bills.

Whenever you read anything on the Internet about houses, the first questions to ask are, “Where is this person located? What kind of climate do they have there? How similar is his or her climate to mine?”
Often, very honest people sharing information about something that worked well for them can lead you down a path to disaster. The fact that something works well in Arizona or Florida or Montana does not mean it will work in Siler City.

Another problem is that people who write Web pages sometimes simply find information on other Web pages that they think is credible and “recycle” that information over and over. A great example that can be found everywhere is to “caulk around doors and windows.” This will have an impact on your energy bills, but only a negligible effect. Even so, you still find it recommended on a lot of websites and booklets.

Sometimes, this is suggested because it is low in cost and easy for homeowners or volunteers to do. It’s true that something is better than nothing. I guess each of us can decide whether we want to spend time feeling like we’re doing something or actually having a significant impact.

Another issue is that a lot of the information out there is published by product manufacturers or distributors. This is often solid information, but it is presented in a way to make the product look as good as possible. Many manufacturers invest substantial amounts of money to test and improve their products. They really do want them to work well, since that’s the only way they’ll have long-term success in the marketplace.

On the other hand, sometimes the research data are presented in a way that comes very close to deception. A window company, for instance, may determine that replacing old windows with new energy-efficient windows will reduce the heat loss or heat gain through the windows as much as 50 percent. A local window replacement company takes that data and advertises that you can save 50 percent on your utility bills by installing new windows.

Many people will read that and think it means they will save 50 percent of their entire utility bill. But, obviously, it won’t have any effect on the lights, water heater, refrigerator or dryer. It won’t have any effect on how much heat is lost or gained through the attic, or through leaks in the ductwork, for example. It will only have an effect on the portion of your heating and cooling bill that’s caused by heat lost or gained through the windows, which is typically 10-20 percent of the total heating and cooling. In most of North Carolina, approximately half of your total bill is heating and cooling, so replacement windows might save you up to 20 percent of 50 percent of your bill. If you pay id="mce_marker",200 a year (average id="mce_marker"00 a month) then you might save as much as id="mce_marker"20 a year if you replace all of your windows.

Over the next few months we’ll look at some other common recommendations. Will you really save money by getting your furnace or AC unit tuned up? How about changing the filters? Replacing light bulbs with CFLs or LEDs? Insulating your attic or your walls? Stay tuned to find out.

About the Author

Arnie Katz is the former building science consultant for Advanced Energy in Raleigh. advancedenergy.org

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