Leaky Homes Waste Money, Decrease Comfort and Harm the Environment

Created:
Tue, 2009-09-22 10:08

Summer officially arrived on June 21, but for most people it got here at the start of June when a big heat wave hit the Carolinas. Along with the heat, many local area homeowners found out the hard way that their central air conditioning systems cannot keep up with scorching outside temperatures that regularly exceed 90 degrees. What most people do not realize is that while their central air system may seem to be the source of their troubles, there is a very good chance that the rest of their home is actually the problem.

The biggest mistake homeowners often make when their house cannot stay cool in the summer is to buy a bigger air conditioning unit. Much of the time, the real source of discomfort is an improperly sealed building envelope that lets good air escape to the outside and sucks bad air in to replace it. It is the same as leaving a window open and then complaining that your AC is not doing its job. Aside from reducing comfort, home air leakage costs money, as it takes more electricity to heat or cool the same space. Your AC system could be cooling your home’s roughly 75 degree air, but instead it is working harder to cool the humid 90 degree plus outside summer air. In fact, the Department of Energy (DOE) estimates that fixing home air leakage is the most cost-effective method of increasing efficiency and saving money.

One common misperception is that a home should be allowed to “breathe.” While there should be proper ventilation, uncontrolled home air leakage is all too common of a problem. The DOE recommends that a healthy and energy-efficient home should turnover 100% of its air every 3 hours, while a leaky home will often complete the same turnover in as little as 30-45 minutes. The best air conditioner in the world would only be about 10% efficient if hooked up to a home like that. Of bigger concern than the amount of natural air flow in a home is from where new air is pulled. Leaks often pull unfiltered air from crawlspaces and attics, which can carry with it dust, pollen, allergens, mold, radon, and pollution. So what are your home’s most common air infiltration problems? Areas around windows and doors are usually the first places people consider.

However, there are also attic access hatches, recessed lights, bathroom fans, electrical outlets, and more. All of those little gaps and cracks can add up to the equivalent of having a large window open at all times. A trained energy auditor can use a special diagnostic tool called a blower door to identify major sources of air infiltration. This equipment depressurizes a house to quickly expose leaks and estimate the amount of air turnover it experiences under normal conditions. Once the leaks are identified, a homeowner will know which problem areas to work on. The good news is that fixing home air leakage is usually much less expensive than buying a bigger air conditioning unit. Depending on the age and quality of a home, solutions can sometimes be as simple as caulking and weather-stripping around windows and doors. With today’s energy prices, payback on air sealing can be as little as three months.