September 2018 EnergyWiseSM Tip: Over Your Head
If you’re not there already, go to the top floor of your home and look up. What do you see? A drywall ceiling? HVAC ducts? Light fixtures? An attic access door? If your home is like most, an unconditioned attic is on the other side of that ceiling. Ask yourself this question: This January, what will the temperature be like up there? Without realizing it, you could be losing more than 30 percent of the heat in your home through your ceiling!
When looking for ways to make improvements, first consider light fixtures, and in particular, recessed "can" lights. Can lights, especially those manufactured before 2004, have plenty of holes and gaps to allow conditioned air from the living space to escape into the attic. Because these fixtures traditionally use hot, incandescent bulbs and protrude up, they should not be covered with insulation without first installing a cover with an airtight barrier. While you may choose to make covers yourself out of sheet metal or lumber, most home improvement stores offer air-tight can light covers made of a fire-retardant material that are designed specifically for this purpose. Once the cover is ready for installation, apply spray foam insulation to seal air leakages and secure it in place. Ceiling penetrations for other light fixtures or ceiling fans may also leak air from your conditioned space and should be sealed in a similar manner.
If you saw a register, grille or air diffuser when looking up, you have ductwork running through your attic. Is it insulated? Uninsulated ductwork running through unconditioned spaces can lose as much as 40 percent of a heating or cooling system's energy. Special insulation designed for ductwork with at least an R-6 insulative rating and a vapor barrier is also available at home improvement stores.
If you have air conditioning, properly insulated ducts are necessary for more than energy efficiency. During the summer, cool air passing through metal ducts in warm attics can cause condensation on ductwork, and dripping will occur. This can lead to mold growth and safety issues. Uninsulated ducts are also at risk of becoming rusted and leaking conditioned air.
How about an attic access door or panel? If you have stairs or a ladder mounted above, install a molded insulation cover above the access door. If you have a simple door or panel, you can easily insulate yourself with rigid-foam insulation panels and construction adhesive. Finally, install weather stripping to reduce air leakage around the perimeter of the door or hatch.
Now, for the big one. Consider your attic insulation. Due to temperature, compression, aging and moisture accumulation, some insulations lose their R-value over time. The Department of Energy recommends Nebraska homes have an R38 insulation value or better. Insulation batts and blankets are made of fiberglass or mineral wool and are most commonly used in unconfined areas, like unfinished attics, roofs and under floors. Batts and blankets often have an R-value of 2.9 to 4.0 per inch of thickness. Blown-in loose-fill insulation is commonly made of cellulose, glass fiber, mineral wool, perlite or vermiculite. It can be easily blown or spread into areas needing more insulation. Loose-fill insulation usually has an R-value of 2.2 to 3.8 per inch of thickness. If you don’t have at least one foot of either of these insulation types, you probably have an energy efficiency improvement opportunity.
Note that reflective insulation or radiant barriers are sometimes installed in attics to reduce summer heat gain and reduce cooling costs. Barriers consist of a highly-reflective material that redirects radiant heat away from the living space rather than absorbing it. Unfortunately, the same effect occurs in winter when radiant heat is beneficial. Since Nebraska has a heating-dominated versus cooling-dominated climate, the summertime benefit is often negated by increased energy use in colder months. Some representatives of radiant barrier material claim their product will provide an equivalent of thermal insulation with an R-value of 25 or higher. These claims are not substantiated because these products by themselves do very little to reduce heat conduction like thermal insulation materials.
If your attic has six inches or less of insulation and you use primarily electricity to heat it, there is an EnergyWiseSM program to help if you want to add an R-value of at least 19 or six inches of blown-in insulation. By participating in the Residential Attic Insulation Program, customers are eligible for an incentive of $0.15 per square foot of insulation with a maximum incentive amount of $300 per existing residential dwelling. New construction and/or additions do not qualify.
Your local utility and Nebraska Public Power District want to help you make the most of your home energy use. For more ideas on how you can make your home or business EnergyWiseSM, along with possible energy efficiency financial incentives for a variety of improvements, contact your local utility or visit www.nppd.com.