September 2020 EnergyWiseSM Tip: Infiltration!
By: Energy Efficiency Program Manager Cory Fuehrer
Infiltration! It sounds like a headline ripped off the daily news or part of a book title from a Tom Clancy action/thriller. You might dismiss what I will share as a conspiracy theory. However, you should know, this one likely involves you.
Consider the following: Everyone uses energy to heat and cool their homes. In fact, most Nebraska homes use four times more energy per year to keep them warm than to keep them cool. Thus, the forces of inadequate original construction and decay of building materials over time silently feed the infiltration monster hiding in so many homes. Ultimately, it leads to people asking, "Why is my electric bill so high?"
Conspiracy? I ask you to consider these two deceptive energy wasters and view your home in a different dimension. It requires taking a "Twilight Zone" perspective. As Rod Serling would say, "It is a dimension as vast as space and as timeless as infinity. It is the middle ground between light and shadow, between science and superstition…" It is the realm of infiltration in your home!
Infiltration is caused by wind, negative pressurization of the home, and air buoyancy forces combined with how these variables allow outdoor, unconditioned air into your living space. To put it simply, these intruders are leaks!
Where do the biggest offenders occur? According to the Department of Energy:
- • Floors, walls and ceilings (average 31%) - This includes recessed can lights that mount in an attic. If they aren't sealed and insulated, they can leak. Another common oversight is band joist areas, which are where the house's frame makes contact with the basement or foundation. This area on homes built prior to the 1970s was seldomly sealed, while newer homes may have missed proper sealing during construction.
- Ductwork (average 14%) -You might think since most ductwork is inside the space you're trying to heat and cool, leaky ducts don't matter. They do. They can create pressure imbalances that draw outside air into your home. Even in "tight" homes, all duct unions and joints must be sealed.
- Windows (average 10%) - Most people suspect windows as the main reason for energy loss in their home. In reality, unless your windows are of poor quality or have outlived their useful life, there's another lurking problem. While you might suspect the window itself, most infiltration usually occurs around the window and how it mounts through the wall. Caulk ages and cracks over time. If sealants weren't used when your windows were first installed, you might assume costly full-scale replacement is necessary over inexpensive retrofit sealing. The bottom line: If you feel a draft around the trim of your windows on windy days, you've got infiltration. Seal it up!
- Fireplaces (average 14%) - Who doesn't love a toasty fire on a cold night? While ventless fireplaces and wood stoves are popular, their penetrations through an exterior wall often cause infiltration concerns. Done right, they provide an excellent source of heat and ambience. Done wrong, they literally send your heat up the chimney!
- Penetrations (average 10%) - Whether it's plumbing vents through the roof or dryer vents through the side of your home, inadequate sealing can allow unwanted air inside. Foam seal all penetrations to ensure no unwanted air from outside comes in, as well as any unwanted "critters."
Conspiracy? I think not. Be EnergyWiseSM!
Southwest Public Power District and Nebraska Public Power District want to help you make the most of the energy they provide you. If you’d like additional information on finding and reducing infiltration in your home, please reach out to them. You may be eligible for incentives to reduce the cost of energy efficiency improvements. Southwest Public Power District can update you on other incentive opportunities or visit www.nppd.com.