In an attempt to keep up with new trends I try to read about everything I can get my hands on related to residential construction. One of my favorite sources is a relatively obscure periodical called "The Journal of Light Construction." In the June edition of the JLC, an article appeared to dispel some common myths about energy efficiency. Because this article was such an eye opener for me I thought I would share some of these myths with my readers.

1. Replacing old windows: On the surface it seems logical that replacing old inefficient windows will save money. Well, there is no question that it saves money; the question is, can you wait for the payback? According to estimates from the U.S. government Energy Star Web site, in Atlanta, replacing single pane windows with double pane, low E windows can save as much as $465 per year. According to my and the JLC's research that is about the replacement cost of one window. So, count the windows in your house. My house has 25; that's 25 years to pay back the cost of window replacement.

2. Air conditioning and comfort: With our hot summer temperatures and high relative humidity we Georgians typically find air conditioning a necessity, and all we need to stay comfortable in summer. But what is it about air conditioning that makes us comfortable? The air conditioner in your car or home actually performs two functions, both of which contribute to your comfort. First, as most of us know, the air conditioner cools the air. Second, and somewhat less obvious, the air conditioner removes humidity from the air. This dehumidification is also critical for human comfort. In an older, inefficient home the loss of air from the home on a hot day will result in the air conditioner running more frequently. That is good for dehumidification because the humidity is only removed when the air conditioner is running.

In more energy-efficient homes, however, the air conditioner does not have to run as long to cool the house. This can be a problem because it can allow humidity levels to elevate. These elevated humidity levels, in the worst case, can result in a cool, humid and uncomfortable environment. So, the traditional wisdom of air conditioning being all we need for summer comfort may not hold true in tight construction. The solution is additional dehumidification, either with stand alone or whole house dehumidifiers.

3. Caulking the exterior of your house saves energy: I myself have recommended yearly caulking of the exterior of houses for energy savings. Caulking can be a good idea when done properly. However, not every hole should be caulked. It is important to understand that houses must breathe. Some water vapor will always get into walls, floor and attics. This water vapor must be able to get out before it condenses against cool surfaces and becomes liquid water that can cause wood structures to rot. Some examples of improper caulking from the JLC article are weep holes in windows, and the bottom edges of horizontal lap siding. I also have seen improper caulking around storm windows, and in weep holes in brick veneer siding. A better idea for the weekend warrior is to use a can of expandable foam and seal gaps around electrical outlet boxes and light switches, around plumbing or electrical penetrations into the house from attics and basements, and around recessed light fixtures from the attic.

Do you have a home repair question? Send an e-mail to Ask the Inspector at homestyle@ajc.com.